Rebuilding Questions

[eulark]

I kinda explained my situation in the new member section, but to clarify, i have a 2003 250 that i blew a rod bearing on. The guy who pulled the motor apart for me also for heavy carbon deposits on the pistons so i was running too rich or hot. ( BTW is that normal or should they not be black? I know the 250 was at 13,000 rpms alot but the guy before me messed with the carbs)

Anyways, after some craigslist searching, while the guy was pulling my motor apart, i found a guy in Raleigh who sold me two boxes full of parts. Enough to build a motor by itself. It came with a bottom end completely intact. The rods have no play and i didnt feel or see any metal shavings and from peeking through the oil filter hole, the gears look good. Is there any other way of testing it to know if its good without pulling it all apart? If this bottom end is still good, i could leave it be and just put the good top end parts on and have a good running motor ideally.

Also, can i just clean the pistons up and reuse them? Or should i try to get new ones? Thanks for looking.

Also trying to pinpoint the best place to buy the remplacement parts i need like gaskets etc.

Thanks for reading and helping me get my baby back up and running.

[Racer x]

It is hard to answer. Cheap cycle parts is where I get my parts. As for the box. You will need to have the mechanic look at the stuff. You can reuse pistons but new rings are good. Maybe start with photos of what you think are the best parts.

[eulark]

Yeah I'm thinking i want to lay everything out and take some pics any ways. I was referring to my old pistons however from my motor since the top end was still good. Granted these boxes had plenty of top end parts too. Basically though, the complete bottom end that came in one of the boxes seems solid.
Pics tonight i guess are in order.

Thanks

[n4mwd]

Pistons are nearly always black. Just clean them with some purple or easy off oven cleaner. If you have a good tight bottom end, then that sounds like a good way to go. Just try to check the transmission and clutch to make sure everything is good there.

As for parts, I use ronayers.com, they are the cleapest for OEM parts, but they charge a $15 shipping fee. If you are getting a bunch of stuff then they are worth it, but if I just need a little $2 part, then I go to the local dealer.

[eulark]

Originally Posted by n4mwd

Pistons are nearly always black. Just clean them with some purple or easy off oven cleaner. If you have a good tight bottom end, then that sounds like a good way to go. Just try to check the transmission and clutch to make sure everything is good there.

As for parts, I use ronayers.com, they are the cheapest for OEM parts, but they charge a $15 shipping fee. If you are getting a bunch of stuff then they are worth it, but if I just need a little $2 part, then I go to the local dealer.

Any particular method of testing the gears and clutch? I somewhat remember there being a power drill involved but i cant remember. Also, is there any gaskets on the bottom end that i should replace while i have it sitting there?

[n4mwd]

Originally Posted by eulark

Any particular method of testing the gears and clutch? I somewhat remember there being a power drill involved but i cant remember. Also, is there any gaskets on the bottom end that i should replace while i have it sitting there?

There wasn't much for gaskets on the lower end. Its stuck together with Hondabond HT. The only gaskets are the two side cover gaskets and the oil screen gasket underneath. There are a few oil seals at the output and shifter shafts that you can change if you want to. The top end has the upper and lower cylinder head gaskets. The top one should be changed. Some say to change the lower one too, but I'm not convinced that routine changing it is necessary unless its damaged.

Test the clutch plates and springs with a caliper to make sure they are within spec. The clutch basket nut is supposed to be replaced, but I know some people don't.

Once you have the bottom end apart, just pull the gears out and examine them. Look for chipped teeth and bearings that don't feel right.
You can also spin it by hand to test the shifting.

[eulark]

Originally Posted by n4mwd

Once you have the bottom end apart, just pull the gears out and examine them. Look for chipped teeth and bearings that don't feel right.
You can also spin it by hand to test the shifting.

as far as pulling the bottom end apart, do i need to pull the clutch basket to do that? I know the guy that has my other motor has been struggling with pulling the clutch basket.

[n4mwd]

Originally Posted by eulark

as far as pulling the bottom end apart, do i need to pull the clutch basket to do that? I know the guy that has my other motor has been struggling with pulling the clutch basket.

I don't know if you have to take off the clutch basket. The nut may be torqued against the bearing so that would make it really hard to split the case. I do know that you can leave the flywheel on, but not taking that off makes it hard to get one of the oil tube bolts off. You'll need a flywheel puller if you take that off.

The clutch basket isn't that bad to get off. Just use an impact wrench and a 27mm socket (Harbor Freight sells it for $3). They also make clutch basket tools to hold the inner and outer rings together so you can get the nut off. The nut has about 100# of torque on it. Its much harder getting it back on than off. To get it on, you need a torque wrench.

[alex.s]

gotta pull the clutch basket to get the oil line off on the newgen at least. 3 rebuilds and i still have not removed the flywheel hub yet. no reason to. i use an impact and a clutch basket grip tool from cyclegear (looks like a long pair of vice grips with weird sideways teeth on the end)

[n4mwd]

Here's what I used. I made this out of an old disk that I was replacing. There are four angled Tang's that are riveted on the disc. I put this in between the two baskets and then use a screwdriver or something to hold the assembly from rotating. Or you could just buy one. I think motion pro makes one just like this but with a nice handle for about $15.

EDIT: It looks like its EBC and not Motion Pro. Here is one for sale on ebay.
EDIT2: The part number is EBC CT016 of the one that fits the pregen.

[n4mwd]

Originally Posted by alex.s

gotta pull the clutch basket to get the oil line off on the newgen at least. 3 rebuilds and i still have not removed the flywheel hub yet. no reason to. i use an impact and a clutch basket grip tool from cyclegear (looks like a long pair of vice grips with weird sideways teeth on the end)

What oil line? The only oil line I saw was the one under the flywheel.

In any case, I've seen plenty of people split the case without taking the hub off, but never anybody doing it without taking the clutch basket off.

[eulark]

Bringing this back up from the dead.

Im starting up on the rebuild, but i have some questions.

1. Cam Chain tensioner...i wasnt present during the tear down, so is there a source to look at for reassembly of this part? The manual shows a cave man diagram of it.

2. I bought the tool to pull the bottom end apart. My question is do i really want to? To refresh, i bought a bottom end that is supposedly good and i trust the guy. I want to be relatively sure that it is without pulling the bottom apart. Can i turn the motor by hand and shift through the gears and be able to tell it is good that way?

3. What about needing to clean out the bottom end since it has been open for a while? any need?

This is my first real rebuild. I rebuilt a 47cc pocket rocket once, but thats it as far as rebuilding goes. I am mechanically inclined however.

Thanks guys

I cant wait to get back on the road this spring!

[TonyKZ1]

Keep us updated on your progress, I've got an engine or two that I need to rebuild and I've never rebuilt one before. I've done some repair/maintenance on these (valve adjustments, stator replacement, carb repair/rebuild) but just replaced the engines when they had problems. Seems like the supply of pre-gen engines is slowly drying up.
Thanks, Tony

[eulark]

will do. Hopefully the fact that the bottom end is good will mean that this is really just a top end rebuild plus new clutch and some other things. But i think detailed pictures would be helpful in the future.

And i agree. it looks like there are less engines than before. I know everyone always says you can get a motor for 500 to your door. Now its pushing 700 with shipping. I paid 1000 for my ninja period(granted it was a fantastic deal.)

Oh well, thankfully craigslist exists and i have the parts i need.

[n4mwd]

Just test out your bottom end before you install it.

1. Wiggle and twist the rod a little with your fingers to see if there is too much play. If there is, you'll need to open it up and replace the bearings (>$100).
2. Remove the oil screen and oil filter. Inspect them for IRON shaviings and particles. Do this by putting a magnet inside a plastic baggy and holding it over the screen and filters. A flake or two is not terrible, but a lot is very bad.
3. Aluminum particles are what will be left. A few is nothing to worry about, but a lot is bad.
4. With someone else holding the rods so they don't bind, you should be able to rotate the crankshaft freely by pulling on the timing belt.

If the bottom end is good, then reassembly is pretty simple.

[eulark]

I've played with the rods. The motor i had on the bike blew the bearings so i know what loose feels like. The bottom end i have now the rods are nice and tight. I didnt see an oil filter for it, but i can certainly try to see what a magnet picks up. What about the aluminum? What is a lot? several small particles or several larger ones and just picking up a ton just by swiping my finger there?

Simple sounds nice. At this point I'm more worried I'm gonna find gremlins with the reassembly of the whole bike.

[n4mwd]

Originally Posted by eulark

I've played with the rods. The motor i had on the bike blew the bearings so i know what loose feels like. The bottom end i have now the rods are nice and tight. I didnt see an oil filter for it, but i can certainly try to see what a magnet picks up. What about the aluminum? What is a lot? several small particles or several larger ones and just picking up a ton just by swiping my finger there?

Simple sounds nice. At this point I'm more worried I'm gonna find gremlins with the reassembly of the whole bike.

If you're getting aluminum on your finger inside the oil filter chamber, then you need to open it up to see what is going on. This could be residue from the top end that went bad, or something else. At the very least, you need to open it to clean out the residue.

Splitting the bottom isn't that costly - just time consuming. You'll need new side cover gaskets and the oil screen gasket. That's about the only mandatory parts. Any additional parts depends on what's inside. If the bearings are acceptable, just reuse them. They are too expensive to replace "just because." Just don't get them mixed up as to which goes where.

[eulark]

So here we go. Tonight i went through my box of parts and took some inventory of what i have. I also checked out the bottom end how i could.

Here's what i got.

First image. Here is a glimpse of the inside of the bottom end im going to be using. Everything looks clean for the most part and the gears have all their teeth and no cracks or anything.


Next up is some oil that leaked out when i removed the oil filter. Those pieces of metal are the only one that came out at that part.


The inside i swiped with my finger pretty good and this is all i got


This rod here is what i spun around while peering into the bottom end. All the gears have their teeth and there is no aluminum shards anywhere.



I believe this motor came from a 2006 since the number on the motor is EEA25XXX. Hopefully that means it is actually a very low mileage motor. It seems to be clean enough. It looks like the tear down was due to a holed piston if the one in the box with the motor came from the same motor.

So hopefully, i can just transfer my clutch basket over, find the best clutch plates i have and then put in my top end with freshly cleaned pistons from my old motor and be good to go.

I guess we will see what tomorrow bring.

Thoughts and ideas will be accepted

[n4mwd]

Originally Posted by eulark

I believe this motor came from a 2006 since the number on the motor is EEA25XXX. Hopefully that means it is actually a very low mileage motor. It seems to be clean enough. It looks like the tear down was due to a holed piston if the one in the box with the motor came from the same motor.

So hopefully, i can just transfer my clutch basket over, find the best clutch plates i have and then put in my top end with freshly cleaned pistons from my old motor and be good to go.

I guess we will see what tomorrow bring.

Thoughts and ideas will be accepted

The aluminum flakes could be from the pistons or top end. Its a big question mark. If any of that got past the filter, you'll have a big mess. The center hole in the top of the oil filter section is the main inlet to the engine. Check that with your finger to make sure no particles are in there. Even one particle can ruin the bearings on the crank. This bike has very high tolerance bearings (measured to the micron) so it doesn't take much to mess it up.

Based on your description and photos, I doubt there is anything wrong with the bottom end. Its just a matter of contamination.

Regarding the transmission, its very rare to have a problem with it, but I have heard of people who did.

[eulark]

I wasnt terribly worried about the tranny, but i figured while i had the chance i might as well check it over to be sure. Id hate to have built the whole thing and got it on the bike only to discover there was no third gear or something haha.

No aluminum shavings anywheres. So I think im good.

Anyone know of where i can get calipers for cheap to measure the clutch plates? Also as a side note, all the ones i have seem to be saturated in oil. I dont remember if that's how they are supposed to be.

Thanks guys!

[n4mwd]

Originally Posted by eulark

Anyone know of where i can get calipers for cheap to measure the clutch plates? Also as a side note, all the ones i have seem to be saturated in oil. I dont remember if that's how they are supposed to be.

The fiber clutch discs should actually be soaked in oil overnight before assembly. The metal ones only need to be coated. When installing the clutch basket, make sure the basket is not resting on the oil pump gear. It should be meshed nicely, but its easy to miss that and blow the engine.

Harbor freight is a good source of cheap calipers. You can usually find a coupon to get a digital set for about $10.

You will need a new clutch cover gasket, but the flywheel cover gasket can be reused if you use RTV on it (its metal). You can order that when you get the oil screen cover gasket.

[eulark]

Thanks for that link D. I'll have to brush up on the oil pump gear etc. and how it goes together. What about the clutch itself. I feel like i read somewhere that there is a set of washers or something that go bad sometimes on the back of the basket?

I'll get all the gaskets i have sitting here together and see what i have and what i need. I will need a clutch cover gasket for sure, but both the flywheel cover gaskets look good i know. Im somewhat confused by the various other gaskets ive found including one that looks like it was made of cork. Looks like a head gasket?

By the way n4mwd, i'll owe you a case of beer once i get this up and running.

[eulark]

Thanks for that link D. I'll have to brush up on the oil pump gear etc. and how it goes together. What about the clutch itself. I feel like i read somewhere that there is a set of washers or something that go bad sometimes on the back of the basket?

I'll get all the gaskets i have sitting here together and see what i have and what i need. I will need a clutch cover gasket for sure, but both the flywheel cover gaskets look good i know. Im somewhat confused by the various other gaskets ive found including one that looks like it was made of cork. Looks like a head gasket?

By the way n4mwd, i'll owe you a case of beer once i get this up and running.

[rickthefix]

try powersportsplus.com for parts, have not found any cheaper anywhere & pretty low shipping prices, the link might redirect to partszilla.

[n4mwd]

Originally Posted by eulark

Thanks for that link D. I'll have to brush up on the oil pump gear etc. and how it goes together. What about the clutch itself. I feel like i read somewhere that there is a set of washers or something that go bad sometimes on the back of the basket?

I'll get all the gaskets i have sitting here together and see what i have and what i need. I will need a clutch cover gasket for sure, but both the flywheel cover gaskets look good i know. Im somewhat confused by the various other gaskets ive found including one that looks like it was made of cork. Looks like a head gasket?

By the way n4mwd, i'll owe you a case of beer once i get this up and running.

There are no gaskets made of cork in the Ninjette. The head gaskets are both metal. The flywheel cover gasket can be reused, but you need to coat both sides with RTV and then coat the joining surfaces with a thin oil to prevent them from sticking. The clutch cover gasket is paper so it has to be discarded, but you can cut one out of gasket paper if you don't have a factory one.

As far as the clutch basket, there is a bevel washer that goes in first, but it doesn't usually go bad. The only part that has to be replaced is the big nut on the flywheel. The manual says it has to be replaced for some reason. For the oil pump gear, all you have to do is to make sure its meshed with the clutch basket gear. If its not meshed properly, it will bend the oil pump shaft and damage it then the engine wont get enough oil.

[eulark]

Here is that gasket i was talking about.



And its flimsy


So i mean, im guessing its a gasket, but im confused...there wasnt one on my motor i dont think. Was this maybe a cutout by someone for some reason?

[eulark]

Here is that gasket i was talking about.



And its flimsy


So i mean, im guessing its a gasket, but im confused...there wasnt one on my motor i dont think. Was this maybe a cutout by someone for some reason?

[EMSRacer07]

lol wtf. where was that? the head gasket or where the case splits?

[eulark]

I have no idea Byron. It came with the boxes of parts i bought from a guy on craigslist. My motor didnt have anything like it. So im not sure what it is...

[EMSRacer07]

well like n4wnd said the head gasket is metal. the others are paper or rubber. I think someone mentioned that the one between the case is cork but thats like really thick cork. Looks like someone cut it by hand

[eulark]

Actually let me correct myself, the more im looking at it now with the understanding it is not a normal ninjette part, i can see some marker ink along some of the edges. It looks like someone before me traced the head gaskets...I wonder why? Maybe to machine their own?

***edit

haha you beat me to it

[EMSRacer07]

yeah dont use that lol o yeah idk if anyone mentioned this but if you worried about crap in your engine or tranny you can take it to a machine shop to get it cleaned, head, tranny, etc. If not just run cheap oil in it for like the first couple of minutes and flush it and put good oil in.

[eulark]

I really like your last idea there actually haha. Probably what ill do anyways, but im too worried anymore now that ive taken some good looks at the bottom end. I think tomorrow night im going to attempt to remove the clutch basket on my old bottom end. I'll post pics tomorrow of what im dealing with with all that stuff.

[n4mwd]

If you got the new bottom end from the same guy that you got that cork gasket from, then I would say that splitting the bottom end and checking it over is probably mandatory now. The reason is that if he is making his own parts like that, then you need to open it up to see what else he has cobbled up.

Since you already have the clutch cover off, it shouldn't be that big of deal once you have made a suitable stand for it. You don't need to replace any bearings or seals unless they are bad. The only thing you need to put it back together is Hondabond HT (available at your local Honda dealer). Don't use regular RTV because it doesn't hold up. Oh, and you will also need a torque wrench ($10 @ harbor freight).

Most everything is obvious as to how it goes back together, but if its your first time, you should video record it or take lots of still photos. You also have a known good bottom end (albeit broken) that you can use as a reference.

[eulark]

I'm really not sure what that cork thing was for to be honest. The bottom end hasnt been opened up and it all looks good. So Im gonna leave it as is. This summer i will probably pull my old one apart and really rebuild the whole thing for a learning experience. But i think this one i have is fine. Like i said, the boxes of parts i bought, are from a couple motors that the guy compiled. If the motor blows though, you definitely get a "I told you so" moment. haha.

Anyways, i have 5 good pistons, 2 of which are really good. All of them have all the rings and stuff. How do i determine which rings to use, plus the little holding ring pin things?

[n4mwd]

Originally Posted by eulark

I'm really not sure what that cork thing was for to be honest. The bottom end hasnt been opened up and it all looks good. So Im gonna leave it as is. This summer i will probably pull my old one apart and really rebuild the whole thing for a learning experience. But i think this one i have is fine. Like i said, the boxes of parts i bought, are from a couple motors that the guy compiled. If the motor blows though, you definitely get a "I told you so" moment. haha.

Anyways, i have 5 good pistons, 2 of which are really good. All of them have all the rings and stuff. How do i determine which rings to use, plus the little holding ring pin things?

Use the same pistons that were in your bike to start with. Don't take the rings off the pistons because they break easily - and are expensive. Pistons are balanced to the rod so don't mix them up.

The manual says that you have to replace the round spring clips that go on both sides of the wrist pin to hold it in. They are worried it will come loose and score the cylinder. I don't know if that is true, but its what the manual says.

If you are positive that he hasn't dropped anything down inside the short block that can get knocked between two gear teeth and damage them, then you don't have to rebuild it. The cork thing is his attempt to make his own head gasket. This might work for a 1957 chevy, but not Ninjas.

[eulark]

Haha, he was an older fellow. He had just sold his 250 and bought a gsxr i think. Maybe it was him, but i feel pretty confident about it.

Unfortunately, my old motor was torn down by a family friend, and he took the rings off my pistons. They arent broken however and i have a ring compressor somewhere. I will probably go ahead and replace with new wrist pins to avoid any unnecessary issues.

With removing the clutch basket, i have the tool, and a socket big enough, but will i still need an impact wrench to pull it off? Because that i dont have.

[n4mwd]

Originally Posted by eulark

Haha, he was an older fellow. He had just sold his 250 and bought a gsxr i think. Maybe it was him, but i feel pretty confident about it.

Unfortunately, my old motor was torn down by a family friend, and he took the rings off my pistons. They arent broken however and i have a ring compressor somewhere. I will probably go ahead and replace with new wrist pins to avoid any unnecessary issues.

With removing the clutch basket, i have the tool, and a socket big enough, but will i still need an impact wrench to pull it off? Because that i dont have.

To get the clutch basket off, you need something that can deliver a lot of torque. A breaker bar will work.
You need about 100# of torque on that nut. The 27mm socket is about $5 at Harbor Freight.
An impact wrench makes it easier, but not required. You'll need something to hold the basket together like this one I made:


Or you can just buy one. You will also need a chain vice grip to hold the whole assembly from turning.

As long as the rings don't break or bend, you can use them. Just be sure they are right side up and the crack is oriented the right way.
You don't need new wrist pins, you need wrist pin keepers - the wire circlip things on the ends.

You'll find it much easier to work if you have the whole thing on a sturdy engine stand.
This is the one I use:



I have this one connected so that I can split the case, but if you aren't doing that, you can simply connect to the two rear engine mounts.

[eulark]

I have this tool already
http://www.oemcycle.com/Item/product...m_campaign=NXT

The socket i also have, although im thinking it may be a star style, so im pretty sure i dont want to put 100# of torque on it, so there's another thing going to the list. Guess its time to start actually making the list.

So far, i have on my list

new side cover gaskets
oil screen gasket
Clutch Basket Nut
Clutch Spring Bolts, (i'll post a pic of what happened to mine later)
wristpin circle clips
Oil filter
gasket sealer? (do i really need this stuff and what kind and for what places eg head gasket stuff is different from side cover stuff)

I think that covers the basics from just the motor, later on i will have to refurbish the whole bike.

Any thing else that anyone can think of that should probably be replaced? I might as well get a new sprocket too.

[eulark]

Oh, and im looking into the engine stand, but unfortunately i live in an apartment complex and a small apartment at that, so i may have to find an alternative. I would love one though. Maybe i could get a table top one fabbed up... hmmmmm....