Cam Chain replacement, possible engine damage

[Ginganinja]

Ok so here's the run down, with full disclosure. The bike is an 07 pregen 250 with 41k miles on it. so i was having an issue with what sounded like a valve ticking, so i decided to pop off the cover and do a valve adjustment. When i opened the top and started adjusting the valves there were two things i noticed,

1. One of my intake rocker arms on cylinder 2 wasn't there....


i found most of it in the top in a crevice tho, broken, i'm still missing a piece of it, that i believe fell down where the cam chain is.

2. The cams seemed to be a little off, in the sense that the lobes for TDC on my engine didn't seem to match this picture which i found on the 250 riders club page:

instead the cams were slightly outward more like this:


Well i didn't think much of it at the time, i replaced the rocker arm, and began adjusting the valves when i noticed as i turned the engine from the crankshaft, that it was jumping. Upon closer inspection, i realized my cam chain is really really loose. and possibly skipping teeth?



So I pulled out the tensioner and it was really quite a mess, so i cleaned it and put it back inside the bike to no avail. The chain tightened some but not enough, so a chain replacement is obviously in call for without even having to measure it.

The issue here that i'm worried about is that the failure of the cam chain tensioner caused the cams to shift one to two teeth in the chain from where they were supposed to be due to slack, eventually causing the rocker arm on the intake valve to break. This may be a silly question but what are the potential effects of the cams shifting like this? it would either retard or advance the exhaust or intake timing correct? causing the valve to slap the piston?

So is replacing the cam chain, the camshaft sprockets, possibly the tensioner, and readjusting the valves going to fix this issue or may i have caused more damage in the process that I will run into as i tear into it and get the head off?

Also, if the piece from the rocker arm has fallen into where the cam chain runs, is there the possibility that it will end up in the crankcase, or is it blocked from going into the crankcase, and i will most likely find it when replacing the cam chain?
Any insight or advice on replacing the cam chain, removing the engine, the cylinder head, or anything else that i might have missed is also greatly appreciated!!!

As far as parts go, I am anticipating that I will need the following:
the chain
new cam sprockets
cylinder head gasket

Are there any other parts, pieces, or gasket cement that I may want to use or replace while i have the engine torn apart?


I will update the thread with more pictures and info as i begin to tear into it.

[Motofool]

Welcome to Ninjette.org, Andrew !!!

Sorry to read that this has happened to your bike.

The chain may have or not jumped out of synchrony before you opened the valves' cover.

If it did it before, you may have one or more bent valves.
If it did not, you may have caused the jump by rotating the engine against its natural rotation.

There is no reason to assume that the chain needs replacement, unless you measure it as specified in the repair manual.

I would time the cams and chain and run a leak down test to verify any bent valve.

Please, see this link:
http://www.dansmc.com/leakdown.htm

[Ginganinja]

Originally Posted by Motofool

Welcome to Ninjette.org, Andrew !!!

Sorry to read that this has happened to your bike.

The chain may have or not jumped out of synchrony before you opened the valves' cover.

If it did it before, you may have one or more bent valves.
If it did not, you may have caused the jump by rotating the engine against its natural rotation.

There is no reason to assume that the chain needs replacement, unless you measure it as specified in the repair manual.

I would time the cams and chain and run a leak down test to verify any bent valve.

Please, see this link:
http://www.dansmc.com/leakdown.htm

Thanks for the welcome!!

Ok so I am 99% sure that the sprockets shifted in the chain before i even removed the valve cover, why do i think this?

My reasons for this are:

*new symptom*
Lately as i had been riding the bike i had been experiencing what i thought had been the clutch slipping when taking off from stop lights, except it wouldn't rev like a slipping clutch normally does, instead it would feel like there is a slight loss of power and then all of a sudden the engine would engage, it felt almost as if i had just put the bike into first from neutral except i was in gear the whole time and moving. Upon the new insight that the chain is loose, i believe this symptom was actually the slack in the chain causing it to come off the sprocket such as in this picture, and when it finally realigned on to the sprocket it caused the rough engaging feel of shifting from neutral to first.

My second reason is that, i did not rotate the crankshaft backwards as to cause slack in the chain, i always rotated it counterclockwise. and if somehow the wrench slipped and it did rotate backwards and cause slack wouldn't rotating the engine in the right direction again cause it to tighten and cure this? whereas i can do a full rotation of the crank in the correct counterclockwise direction and it will still have spots where it comes off the sprockets and then be tighter in other spots.

[Motofool]

I see.

Having a valve that does not open can cause those symptoms as well.

Rockers act like fuses to save the valves, as they are made of a fragile material.
When valve-piston interference happens, something has to yield: the rocker, the valve or the piston (in that order normally).

Another common cause of failure of rockers is over-torque of the jam nut during valves' adjustments.
If that is your case, the rocker may have been broken and the valve may have been not working soon after the last adjustment.

My apologies for assuming wrong rotation of the crankshaft.
The tensioner presses over the vertical run of the chain that is not loaded, back rotation reverses the situation and overload the tensioner.
As that has not been your case, your tensioner (normally the non-return ratchet mechanism) has failed to do its job, allowing excessive slack.

http://faq.ninja250.org/wiki/Cam_cha...sioner_removal

The metal protector over your cam sprockets and under the shaft sprocket (in the clutch compartment, where that lost piece of metal is now) are there to avoid chain jumps even when the tensioner fails.

The slack on the top horizontal run is caused by back pressure exerted by the springs of the valves via the cams in an alternated way.

I am telling you all this long story because replacing the cam chain takes some money and work, which may not be necessary in your case.

[KJohnson21]

I think you might have to pull off the head to see what condition the valves and everything are in.

[Alex]

/moved to pre-gen tech

[Ginganinja]

Originally Posted by Motofool

I see.

Having a valve that does not open can cause those symptoms as well.

Rockers act like fuses to save the valves, as they are made of a fragile material.
When valve-piston interference happens, something has to yield: the rocker, the valve or the piston (in that order normally).

Another common cause of failure of rockers is over-torque of the jam nut during valves' adjustments.
If that is your case, the rocker may have been broken and the valve may have been not working soon after the last adjustment.

My apologies for assuming wrong rotation of the crankshaft.
The tensioner presses over the vertical run of the chain that is not loaded, back rotation reverses the situation and overload the tensioner.
As that has not been your case, your tensioner (normally the non-return ratchet mechanism) has failed to do its job, allowing excessive slack.

http://faq.ninja250.org/wiki/Cam_cha...sioner_removal

The metal protector over your cam sprockets and under the shaft sprocket (in the clutch compartment, where that lost piece of metal is now) are there to avoid chain jumps even when the tensioner fails.

The slack on the top horizontal run is caused by back pressure exerted by the springs of the valves via the cams in an alternated way.

I am telling you all this long story because replacing the cam chain takes some money and work, which may not be necessary in your case.

Ok First off, thanks so much motofool for helping me out, and talking theories with me for why this could have happened, i appreciate all the advice and wisdom.

So now back to the business, to see if i indeed have to tear it all apart and replace the chain.

I'm more than halfway through the process of removing the engine, one because i figured it would be a hell of alot easier to work on it out of the bike, plus if i end up having to replace the cam chain it saves me the hassle of pulling it out later, and plus i needed to change all my fluids anyways, so why the hell not. lol

what do you mean about having a valve not open? as in when the rocker arm fell off and there was nothing there to push the valve down? how else would it not open?

That's great info to know about the rockers. I guess it would help if i included some more info on the engine and the malfunction of the rocker arm too. the engine has 41k miles on it, with the last valve adjustment occurring at 18.5k miles, and done by a shop. So i don't think the rocker arm malfunction was due to improper adjustment and it wasn't anytime soon after it. here's a picture of the broken rocker arm to help you get an idea...

I do believe that the tensioner is ultimately to blame for all this, because when i took the tensioner out to clean it earlier, i noticed grooves on the rod and flat spots on the bearings, which tells me that the ratcheting technique of the tensioner may have not been working properly and letting slack in the chain. The tensioner will be getting replaced either way before i button everything back up as I don't think just thoroughly cleaning it will be sufficient as it didn't take up all of the slack when i placed it back in, and made a couple full revolutions of the crank. Sorry I don't have a picture of it, but i can snap one of the grooves and the bearings if anyone wants to see it. I've also heard someone suggest sanding the grooves smooth on the rod rather than replacing it......Comments on that?

At first I was set on just replacing the cam chain without measuring it, but after your suggestion, i do agree with you that it would be best all around if i do measure it anyways. it will give me definite evidence supporting that it needs to be replaced and it's good peace of mind just to know what the slack was before the project. So when i get the engine out and have the cam shafts off, i'll measure the chain and report back with my measurement. After doing some quick searching, I found that this these are the measurements for the chain:
20 Link length
Standard: 127-127.4mm
Service Limit: 128.9mm

Does that sound right?
I'll report back with anything else i find and plenty of pictures for you guys to look at. keep ideas and suggestions coming!

[Motofool]

Sorry, I don't have time this morning.

Please, see these links:

http://n4mwd.blogspot.com/2013/06/ov...ts-during.html

http://www.ninjette.org/forums/showthread.php?t=133823

http://www.ninjette.org/forums/showthread.php?t=117854

[Ginganinja]

Originally Posted by Motofool

Sorry, I don't have time this morning.

Please, see these links:

http://n4mwd.blogspot.com/2013/06/ov...ts-during.html

http://www.ninjette.org/forums/showthread.php?t=133823

http://www.ninjette.org/forums/showthread.php?t=117854

Those are all great links!! thanks so much. The first one was a great explanation of why not to torque it down too tight, and it looks like that might be why that rocker arm broke instead of the chain after all. it was only the "dog ear" that broke of so maybe i got lucky....

[Motofool]

You are welcome

Let's go over some of your previous comments:

Originally Posted by Ginganinja

............what do you mean about having a valve not open? as in when the rocker arm fell off and there was nothing there to push the valve down? how else would it not open?

Yes, the broken rocker did not push to open one of the valves, which reduced the breathing and performance of one cylinder.
If one or several valves were hit by the pistons and the stems got bent, those may have remained open as they could not retract freely, causing lack of compression and similar performance problems.
That is the reason of performing a down leak test or a compression test.

Originally Posted by Ginganinja

.............the engine has 41k miles on it, with the last valve adjustment occurring at 18.5k miles, and done by a shop.............

These cam chain should last between 80K~100K miles, unless something catastrophic happens.
The service manual recommends more frequent adjustments, in order to avoid damage to the seats and edges of the valves.
The gap gets reduced with use and the valves may not kiss the seats long enough to be properly cooled down, or worse, they may partially leak.

Originally Posted by Ginganinja

I do believe that the tensioner is ultimately to blame for all this, because when i took the tensioner out to clean it earlier, i noticed grooves on the rod and flat spots on the bearings, which tells me that the ratcheting technique of the tensioner may have not been working properly and letting slack in the chain............ I've also heard someone suggest sanding the grooves smooth on the rod rather than replacing it......Comments on that?

Some marks on the plunge are normal, but balls must remain spherical in order for the ratcheting effect to work.
The spring alone cannot fight the slack of the chain; yes, it keeps tension on it but needs the ratchet for preventing any slack to develop.

There is only so much movement that the tensioner can have; there is point in the crankcase that the mechanism hits as the chain elongates to certain point.

I adjust the valves of my pre-gen and clean and lubricate that ratchet every 6K miles.

I hope that your engine is undamaged and that our expert, @n4mwd brings more tips to your thread.

[n4mwd]

Its unusual, that is, lucky, that it didn't destroy all the rockers and maybe do even more damage. I've heard of low and no damage rocker arm failures before, but they are rare.

What it looks like to me is that the previous shop done valve adjustment was done incorrectly and a dog ear was cracked. But it looks like in your photo that it wasn't a clean break so it didn't come off immediately.

Here is what I would do in your situation.

Pull the cams and remove all the rockers. They need to be carefully inspected for cracks and such. As Motofool said, they are the first point of failure if the timing gets askew. First inspect with the naked eye, then go back and do it again with a magnifier to look for fine cracks - especially around the mid section.

Your chain might not be bad. Check the chain guard around the crankshaft to see if its still there. If its broken off, then you probably do need a chain. You also need to find where the broken piece went to.

You didn't mention or show in your photos, but there should be a chain guard that goes over the top of the cam sprockets.

You can test the cam chain tensioner mechanism by using a socket extension and poking it in the hole where the cam chain tensioner plunger goes. You should be able to visibly tighten the cam chain by pushing down on it. Just don't hammer it or push too hard because you can break the hinge.

If its stiff, spray some silicone lubricant (anything but wd40) in there and work it back and forth until its loose. Then squirt regular oil on it and work that in.

If the chain wont tighten up, then its either stretched too far or the tensioners on the sides are bad.

The tensioners are fairly easy to replace, but if you need to replace the chain, it usually means splitting the engine. If the lower chain guard broke off, then it can be done without splitting the engine.

Not sure about valve damage. If you have to split the case to get the chain on, you can inspect them visually. But valve damage will usually show up with a leakdown or compression test.

[Ginganinja]

Before making this thread i had done a compression test with the results being 60psi dry in both cylinders, and 90psi wet in both cylinders. I think however that might not be accurate because my timing might be off if the sprockets jumped the chain. As for now, i'll start working on it and taking measurements tomorrow morning. i'll keep my camera handy to take plenty of pictures.

I have the chain guide that goes over the sprockets, i had just removed it before i took the picture.

I'll check the chain tensioner mechanism as you have suggested too, the engine is out of the bike right now, i'm just waiting to open up the head and take the cams out, measure the chain, inspect the rockers, remove the head, check the valves and pistons, and at that point possibly replace the chain if it needs it

[n4mwd]

With that many miles, I would just go through the whole thing. Change the chain and/or tensioners if they need it. You might also want to take a close look at the rings, pistons and cylinders. The valves can throw the compression off, but the wet difference says the rings may be worn.

I suggest that you don't unbolt the rod ends. You can test the bearings by gently shaking and twisting the rods. They should not do either of that much. If you remove the bolts, you have to buy 4 new sets to replace them with. New bearings are about $10 each half ($20 a pair). I personally use plastigage and only replace bearings that need it.

Do you have a good way to hold the engine while you work on it? Here is what I used....
http://www.ninjette.org/forums/pictu...ictureid=10635

[Ginganinja]

Ok so i have an update for you guys, now that i had time this weekend to finally tear it apart. Again Thank you everyone for all your help, this forum is awesome and you guys are great at helping and really informative.

First off, putting this back together, I'm gonna need a service manual for torque specs, and the head bolt installation pattern. Any opinions on best place to get one. if nothing else, i'll just order one from my kawi dealership. I've just been going off my basic mechanical knowledge, and the internet for now, *gasp* which is not good enough to put it back together.

Alright so i measured the chain, and you guys were all correct, it doesn't look like i need a new chain as it is within specs.
127.5 mm per 21 pins. measured at the center of the pins




However, I know better than to just measure it in one section rather than a few different places, so i moved the chain around and i believe i found the source of the problem, why it was "jumping teeth", one of the links is a little chewed up and causing the chain to kink instead of moving freely.





I didn't find the "dog ear" from my broken rocker arm after removing the head and checking everywhere, but i did find a few metal flakes when i drained the oil, and emptied the oil screen. so it sounds like the "dog ear" fell in there and was chewed into residual metal flakes by the cam chain, which also bent the cam chain and caused it to kink.


SOOOOO..... i need a new cam chain after all to solve the bent link and the kink in the chain, even tho it is still within spec.

Also after inspecting the cams i saw the exhaust cam has some pitting on one lobe, and the intake cam has perpendicular wear marks across the cam that you can feel with your fingernail on two lobes. I think I should replace both of them, correct? There are also a couple rocker arms that need to be replaced due to some wear. One of which was under the pitted cam.
Exhaust cam pitting:



Intake cam wear:


Obvious rocker arm that needs replacement.



And here's some pics of the pistons and valves.
Cylinder 1 Piston:




Cylinder 2 Piston @TDC



Cylinder 1 Valves:


Cylinder 2 Valves: Is that little crack on the edge of the exhaust valve fine?


Both Cylinders valves:



Here's pics of the cam chain tensioner, and why I'm replacing it.
Flat spots on bearings:

Grooves in the rod:

[Motofool]

Somehow, lubrication failed (likely more than once) and metal parts were rubbing directly against each other.

How were the rubber guides of the chain?

There is no way the tensioner was doing its job in that condition !!!

Have you considered buying a used engine in good condition rather than repairing this one?

[Ginganinja]

Originally Posted by Motofool

Somehow, lubrication failed (likely more than once) and metal parts were rubbing directly against each other.

How were the rubber guides of the chain?

There is no way the tensioner was doing its job in that condition !!!

Have you considered buying a used engine in good condition rather than repairing this one?

The rubber guides looked fine to me, but this is my first 250 engine i've seen on the inside of, so i can snap some pics this week and if you don't mind, you can tell me if they look normal, since you have more experience with these things and what they're supposed to look like. I presume that a worn guide would have chain marks or something similar going across it and i didn't see much of those.

I thought about the used engine route, but i don't think there is that much damage internally with this one. and if i spend 2-250 bucks to fix this one and it goes disastrously wrong, then i'll shell out the $4-500 for a used one, and chalk up the $200 as a useful learning experience. Not the best route to go, and certainly not the cheapest, but i guess i can be a bit stubborn. Also with a used engine in good condition, there is no guarantee that the same thing might not happen to that one within a few miles...right?

[Ginganinja]

Do you really think it's that far gone?

[Motofool]

Originally Posted by Ginganinja

Do you really think it's that far gone?

Let's request the opinion of some other members:

@alex.s
@Racer x
@choneofakind
@FvnnyL3tt3r1ng
@dcj13
@old3

[alex.s]

time to buy a 300!

[Ginganinja]

Originally Posted by Motofool

Let's request the opinion of some other members:

@alex.s
@Racer x
@choneofakind
@FvnnyL3tt3r1ng
@dcj13
@old3

Thanks for calling in the back up on this one!

Originally Posted by alex.s

time to buy a 300!

lol It's just my commuter. my heart still lies with my r6.

[Racer x]

Based on the milage alone I am nervous about rebuilding. The cracked valve is very bad. No compression will result if that is not fixed. How much carbon is in the back of the valves?
The cam and rockets are shot. The trashed rocker is an indication than metal has been running through the oil. I bet the crank is showing this.
Honestly I would get a newer 250 or 300. The used 600 seems OK at first but when it breaks you are in the same boat with a very expensive engine to repair.

Why do the piston tops look different? Is it just the photo? Or is number two have raised lumps and number one has recessed portion for the valves to clear?

[n4mwd]

I agree with motofool in that it looks like there is some oil starvation going on in there. The huge pile of metal flakes is very ominous. I suggest you use a magnet to separate the aluminum flakes from the steel ones. Steel = bad, aluminum = not as bad.

It looks like the broken rocker did hit the cam chain after all, but somehow it didn't completely destroy the engine.

I think its time to strip it to the crank and inspect that. The crank is the most expensive part of the entire engine. If that is bad, then repairing the engine gets a lot more costly. The crank cannot be ground down and resurfaced like it can in an old Ford truck.

So basically, I would let the crank condition dictate my next move. A new one is about $500, but they can be had on ebay for $100-$200. If the crank is in good shape, then I would just rebuild the engine. But keep in mind that the tolerance on the crank is measured in microns, so it doesn't take much to destroy one.

If the rod bearings did their job, the crank might be fine. If not, .....

Here is some stuff to help get it back together when the time comes. I also have the torque chart I can post as well.

[n4mwd]

Ebay is your friend when it comes to rebuilding a Ninja 250 engine.

4 exhaust valves - $20
Camshaft set - $30

Rocker arms are expensive. Usually you can find them for about $10 each, but right now there isn't anybody on ebay selling them that cheap. There is one guy selling a set for $75, but they look worse than yours.

[Ginganinja]

Originally Posted by Racer x

Based on the milage alone I am nervous about rebuilding. The cracked valve is very bad. No compression will result if that is not fixed. How much carbon is in the back of the valves?
The cam and rockets are shot. The trashed rocker is an indication than metal has been running through the oil. I bet the crank is showing this.
Honestly I would get a newer 250 or 300. The used 600 seems OK at first but when it breaks you are in the same boat with a very expensive engine to repair.

Why do the piston tops look different? Is it just the photo? Or is number two have raised lumps and number one has recessed portion for the valves to clear?

I'll check the back of the valves and try and get pictures for you. I'll get more pictures of the crank as i open it up, this doesn't sound hope inspiring at all.

As for a newer 250 or 300, mehhh, i like my pregen. I'd rather rebuild or put a new engine in it and keep it then buy one of the newer 250s, except i do like that the 300s are FI. That would be worth it, in itself.

It's just the pictures, I think it was double lighted from natural lighting and garage lighting, so it was casting weird shadows in the photos. both pistons are the same, raised in the center and recessed where the valves clear.

As for the R6, that's not going anywhere, its my track build.

[Ginganinja]

Originally Posted by n4mwd

I agree with motofool in that it looks like there is some oil starvation going on in there. The huge pile of metal flakes is very ominous. I suggest you use a magnet to separate the aluminum flakes from the steel ones. Steel = bad, aluminum = not as bad.

It looks like the broken rocker did hit the cam chain after all, but somehow it didn't completely destroy the engine.

I think its time to strip it to the crank and inspect that. The crank is the most expensive part of the entire engine. If that is bad, then repairing the engine gets a lot more costly. The crank cannot be ground down and resurfaced like it can in an old Ford truck.

So basically, I would let the crank condition dictate my next move. A new one is about $500, but they can be had on ebay for $100-$200. If the crank is in good shape, then I would just rebuild the engine. But keep in mind that the tolerance on the crank is measured in microns, so it doesn't take much to destroy one.

If the rod bearings did their job, the crank might be fine. If not, .....

Here is some stuff to help get it back together when the time comes. I also have the torque chart I can post as well.

Thanks for posting the torque specs and the bolt patterns! Those are a huge help!!

I'll tear it down to the crank then and see what i find. and keep you posted, it might be a day or two, before i get that done though.

it is some sort of miracle nothing else fell into the chain, so i'm hoping i got away with murder on this one, and it's still possible to rebuild it.

[Ginganinja]

Originally Posted by n4mwd

Ebay is your friend when it comes to rebuilding a Ninja 250 engine.

4 exhaust valves - $20
Camshaft set - $30

Rocker arms are expensive. Usually you can find them for about $10 each, but right now there isn't anybody on ebay selling them that cheap. There is one guy selling a set for $75, but they look worse than yours.

Those valves are pretty cheap, depending on whether it's getting rebuilt, i'll pick those up.

The only bid so far on the second link for the cams plus other stuff is mine I already saw that and couldn't pass it up lol

the cheapest i've seen rocker arms go for is $30 a piece, in the last two weeks. I called a couple local shops too and they're the same price.

as for the tensioner, i found a used one on ebay is the same price as buying a brand new tensioner rod and bearing from kawasakipartsnation.com ~$15

[Ginganinja]

Just curious too, will an 08+ engine fit the 07 frame?

[Racer x]

Engine swap Is an option but exhaust front mount radiator all need to be changed.
If you like the older bikes than definitely buy or build an engine. Parts are super cheap. Engines are scarce. Do you have a real ma nine shop in your area. If not you can ship the parts to one. You can't rally build an engine out of junk parts and experience it to last. Head work is easy but you need to address the valves seats and install new valves maybe guides. That is my question about the carbon on the valves. If its all coked up. The guides or seals need to checked.

[n4mwd]

Originally Posted by Ginganinja

Those valves are pretty cheap, depending on whether it's getting rebuilt, i'll pick those up.

The only bid so far on the second link for the cams plus other stuff is mine I already saw that and couldn't pass it up lol

the cheapest i've seen rocker arms go for is $30 a piece, in the last two weeks. I called a couple local shops too and they're the same price.

as for the tensioner, i found a used one on ebay is the same price as buying a brand new tensioner rod and bearing from kawasakipartsnation.com ~$15

Oops, sorry, I thought the cam auction was buyitnow. HERE is a buyitnow with a makeoffer. He might take $25 for the pair.

The first guy was including the cam caps with his auction which tells me that he's an idiot. The cam caps are not interchangeable with other engines. They are a matched set to the head.

I think $30 is too much for a rocker. Unless you are in a hurry, I would wait for someone to sell one at a reasonable price. Of course, the dealer wants about $50 for the same thing.

[Ginganinja]

Originally Posted by Racer x

Engine swap Is an option but exhaust front mount radiator all need to be changed.
If you like the older bikes than definitely buy or build an engine. Parts are super cheap. Engines are scarce. Do you have a real ma nine shop in your area. If not you can ship the parts to one. You can't rally build an engine out of junk parts and experience it to last. Head work is easy but you need to address the valves seats and install new valves maybe guides. That is my question about the carbon on the valves. If its all coked up. The guides or seals need to checked.

Yeah i'd prefer to rebuild this engine, since it's only my commuter, it's not doing extreme duty. And it should be a good learning experience, and way for me to learn more of the ins and outs of an engine relatively cheaply.

I should have a few decent machine shops nearby, none that i know of off the top of my head but I live in LA so there's bound to be some near. Do you think lapping the valves would help at all in this case. or is it strictly replace the valves and have it grinded?

[Ginganinja]

Originally Posted by n4mwd

Oops, sorry, I thought the cam auction was buyitnow. HERE is a buyitnow with a makeoffer. He might take $25 for the pair.

The first guy was including the cam caps with his auction which tells me that he's an idiot. The cam caps are not interchangeable with other engines. They are a matched set to the head.

I think $30 is too much for a rocker. Unless you are in a hurry, I would wait for someone to sell one at a reasonable price. Of course, the dealer wants about $50 for the same thing.

Another member, (i don't know if he would want me to mention his name) pm'd me and said he has a head that he'll give to me at the cost of shipping, to help me out. I owe that man many beers and a thanks! I haven't seen what shape it's in, but it's worth the risk if the cams, valves, and rocker arms are in good shape. That'll solve many of my problem right there.

I have to say that, everyone on this forum has been very helpful, and generous with their time and information. I've stalked around here a couple times before to get some info but never thought about joining til this happened, but i'm sold. i'm gonna stick around. you guys are all very awesome.

i'll post some pics of what i receive with the new head, so we can assess it together.

[baxtc1]

Don't know if this is any good to you, but here is a pic of old and new cam chain guides.

[IMG][/IMG]

[Ginganinja]

Originally Posted by baxtc1

Don't know if this is any good to you, but here is a pic of old and new cam chain guides.

[IMG][/IMG]

Always useful!!

I think mine look somewhat similar to your used ones in the picture. Does that call for replacement? I wouldn't think that yours even needed to be replaced yet, they still look usable.

[baxtc1]

Nah, I only replaced them becauase I bought them when I bought the chain.

[n4mwd]

Originally Posted by Ginganinja

Another member, (i don't know if he would want me to mention his name) pm'd me and said he has a head that he'll give to me at the cost of shipping, to help me out. I owe that man many beers and a thanks! I haven't seen what shape it's in, but it's worth the risk if the cams, valves, and rocker arms are in good shape. That'll solve many of my problem right there.

I have to say that, everyone on this forum has been very helpful, and generous with their time and information. I've stalked around here a couple times before to get some info but never thought about joining til this happened, but i'm sold. i'm gonna stick around. you guys are all very awesome.

i'll post some pics of what i receive with the new head, so we can assess it together.

Its still a good idea to strip it to the crank and see if its still good. With that much metal in the oil, and evidence of oil starvation, the rod journals could be toast. If the crank is bad, its time for a new engine.

Since you have your head off, you should be able to feel any funny business with the rods just by feeling how the pistons move.

Its also possible that the oil flow to the head is plugged somehow. The hose and banjo bolts would be the place to look first for clogs.

[Racer x]

Don't grind the head. It will make problems with valve and piston clearance. And you can put new valves on old seats and lap them . But it is not as good as cutting the seats.

[Ginganinja]

Originally Posted by n4mwd

Its still a good idea to strip it to the crank and see if its still good. With that much metal in the oil, and evidence of oil starvation, the rod journals could be toast. If the crank is bad, its time for a new engine.

Since you have your head off, you should be able to feel any funny business with the rods just by feeling how the pistons move.

Its also possible that the oil flow to the head is plugged somehow. The hose and banjo bolts would be the place to look first for clogs.

Yeah, will do! I still need to replace the cam chain, so i'll have the crankcase split open anyways. I'll check it out and throw some pictures up later this week when i have more time.

Anyone have any other good ideas to hold the engine when splitting the case? Since i don't have one of these guys:

[Ginganinja]

Originally Posted by Racer x

Don't grind the head. It will make problems with valve and piston clearance. And you can put new valves on old seats and lap them . But it is not as good as cutting the seats.

Good to know. I'll start looking for some machine shops.

[n4mwd]

Originally Posted by Ginganinja

Yeah, will do! I still need to replace the cam chain, so i'll have the crankcase split open anyways. I'll check it out and throw some pictures up later this week when i have more time.

Anyone have any other good ideas to hold the engine when splitting the case? Since i don't have one of these guys:

you could prop it up with a small wooden box. But its easier if you get the stand. you can usually find them on sale for around 40 to 50 dollars. the steel for making the adapters will cost you another $10. if you ever have to rebuild another engine, you'll have this ready and waiting.

[Racer x]

I do 99 % of the work on a work bench. Ita a good practice to clean the engine before doing any internal work. Even if its trashed.