Rebuilding Questions

[n4mwd]

Once you have the cap off, the key mechanism comes apart so you can clean and lubricate it. My 2007 was in similar shape. A little cleaning plus some Break Free fixed it.

[eulark]

yep. I cleaned it up and its moving. Now i just need to pick up some grease to keep this from happening again haha.

Note, anyone looking to donate a gas cap lid sans lock cylinder?

[n4mwd]

You should invest in a can of Break Free.

The only place I know that carries it is gun shops. Its used to clean guns.

PS- The only bad thing is that it costs between $10-$30 for a can depending on the size.

[eulark]

Alright, so i cleaned the tank out best i could with tools at hand and the nearby store. Looks pretty good. Cap is installed. Tank now installed. Gas is flowing through the cleaned petcock.

So i hooked it all up to see what happens. First try nothing. Or the second. Just turning over. I spray some carb cleaner in the intake. Try again, little something happens. This cycle repeats maybe three more times. On the last try, I heard a Pop by my left leg. And it gets warm. Weird...So i look down, and find my bike is trying to kill me. There is a flame coming out the side of the carb area, not sure what exactly is throwing the flame, but i figure the carb flooded or something and a backfire threw a flame. Me not being sure what was going on, grabbed a near by hose after blowing it out and still seeing smoke and gave the area a couple blasts of water. I looked and didnt see any damage though. So i think once i recover my courage, I'll jump back out there and give it another go, but its looking like i will need to pull the carbs and give them a good cleaning.

[n4mwd]

I think the US should hire you to go work on North Korea's missiles.

Your petcock should not let any gas through when its not running. If it was, then its broken. Could be partially responsible for your fire.

It sounds like you are saying the the first time you hit the starter button, the engine would not turn over at all. Then you pressed it a second time and it turned over but didn't start. Your battery is suspect. On a Ninja, the battery will continue to crank the engine long after its too weak to work the igniter - the opposite of cars.

You should always have a fire extinguisher available in your work area. But if its backfiring in the first place, that is saying there is possibly an issue with the timing.

I'll need more details to say anything for sure.

[eulark]

Oh no, sorry. The engine turned over like a champ every time. The battery i just filled with water and took to the auto parts store. They tested it, charged it and tested it again. And tested it again a week later for my curiosity's sake. haha.

My guess is that the carbs are just really gummed up. I probably played with the choke too much too. Live and learn i guess.

And it wasnt pouring gas before trying to run it, i pulled the line after the first few tries and then it poured a small stream like it should i think. Otherwise nothing was coming out.

Anywho, i went ahead and pulled the airbox, went ahead and did the battery box cutoff mod to make life simpler next time, and pulled the carbs. I'm taking it all home to clean and possibly do that airbox cutting mod. Have to look into it, but i dont know if it will require rejetting with the airbox mod...I have a full muzzy to install once everything is running and i have some cash to play with. haha. So i would rather hold off on rejetting until then

The timing is good for sure. I triple checked it. So at least in N. Korea our missiles wont be off on that haha.

On the plus side, while i was pulling everything, i realized i lined my back tire up wrong. Slanted to the brake pedal side, so if anything, I caught that. Now its lined up nice and straight too and the chain is nice and tight.


How worried should i be about rust in the gas tank? I know most is cleaned out, but still...


Thanks guys!

[n4mwd]

When the petcock is switched ON or RES, if any gas comes out beyond a drop or two that was stuck in the pipe, then its bad. Could be as simple as the diaphragm spring needing a little stretching. You test it with a short piece of small rubber tubing on the smaller port. Suck on that with your mouth and gas should come on when you suck and go off when you stop. It shouldn't keep running. Not even a trickle.

The carbs may have been flooded. If it was like that long, the oil may be contaminated with gas and have to be changed. When gas gets in oil, it stops being a lubricant so you can burn up your engine if you run it that way. Its an easy test to find out though. The oil will smell like gas and the level will be up.

You should have just used my string method for cutting off the battery box. You don't have to remove anything to do it and the only tool you need is a piece of string. Not sure why people want to do it the hard way.

You'll need to rejet for sure with a different exhaust. Your main problem was probably the petcock, but the carbs are probably gummed up too if they are in an unknown state when you got them. So at the very least they need to be cleaned (2 jets per carb). Check with @choneofakind to see what he recommends for the proper jet size for a muzzy. He's our resident carb expert.

Now the real question is what started the fire? Gas alone doesn't just spontaneously ignite. You need to find out what started it. Is the starter terminal tight? Did you remember to attach the ground to the engine?

PS: Don't worry about rust in the tank as long as it isn't rusted through. The add on filter that goes between the tank and the carb will stop that from clogging up the carb.

[choneofakind]

If you're sticking with the stock intake and a full Muzzy, start with the stock 105 mains, 2-3 washers under the needles, and the standard 2 1/4 - 2 1/2 turns out on the mix screws.

If you're going with a hacked open intake lid, go up to 108's and 2-3 washers.

If you're going with pods, start with 108 mains and test up to 112's. Again, 2-3 washers.


Those are just starting points. Change as needed for your personal bike. Always make sure your carbs are fully functional and not gummed up before changing the jetting. No sense in trying to diagnose jetting with dirty clogged carb parts. It just won't work right.

Remember to sync the carbs after all this work and jetting is said and done.

[eulark]

N4mwd

It was a backfire and i think the flame came from where the carb and the intake connect. It wasnt really well pushed together. It not unheard of. In fact carb backfires are the leading cause of car fires i think.

So i think the flame was just too much gas with fumes going straight back to the carb and voila.

But im going to go ahead and clean the carbs. And the exhaust, filter mod, and rejet will have to wait a bit. I'd rather get the bike running stock first, use that as a baseline, and go from there later.

Thanks for the info chone, i'll be sure to reference all this when it happens haha

I'm using the ninja250.org guides for the carb cleaning, but is there any good threads around here worth going through? I'll be doing searches and all later tonight to study up. But i figure if anyone knows of a good one that would be great.

I just cant wait to get back out there.

Thanks!

[jayman87]

When I rebuilt the engine, I was thinking of it like I was getting my old bike back. I ended up switching crankcases, so I needed a set of new bearings and new piston rings. When it was done, I put the same old Rotella T6 Synthetic Oil in it. A couple days later I went riding with a friend who just bought a new Yamaha FZ6r. He was taking it pretty easy because of the break-in period, where as I was flying the entire time. At some point it occurred to me that with the new piston rings I should be having a break-in period too. Also you shouldn't use full synthetic until the engine is broken in? So am I gonna be replacing these piston rings again?

And how long does it take engine oil to turn completely black? I'm at about 150 miles since the rebuild and while checking oil level I notice it's completely black.

Last thing. I think my clutch is slipping. I notice little dips in power. Best way I can describe them is the bike beginning to shift its weight forward like when rolling off, but only for a split second. I watched my tack while accelerating through second gear and didn't notice any dips or jumps in engine speed. However in that time it may have happened 3 or 4 times. My clutch cable is adjusted with a little bit of slack so it's not like is partially disengaged.
Any thoughs?

[jayman87]

Originally Posted by eulark

I'm using the ninja250.org guides for the carb cleaning, but is there any good threads around here worth going through? I'll be doing searches and all later tonight to study up. But i figure if anyone knows of a good one that would be great.

I just cant wait to get back out there.

Thanks!

For something common like this there are many easy to find guides. I read a few and watch these vids:

https://www.youtube.com/watch?v=vJVHu8itDls

https://www.youtube.com/watch?v=0U3a_FtDSqg

to get an idea of what to do and expect, then cleaned them based on info from all that I learned.

[n4mwd]

Originally Posted by jayman87

... At some point it occurred to me that with the new piston rings I should be having a break-in period too. Also you shouldn't use full synthetic until the engine is broken in? So am I gonna be replacing these piston rings again?

It will probably survive. Are you sure you got the synthetic rotella T6? They have a non-synthetic version. You should still take it easy for a at least a tankful or two. The clutch is probably fine. But you might want to check your chain and make sure there isn't a link sticking.

[jayman87]

Originally Posted by n4mwd

The clutch is probably fine. But you might want to check your chain and make sure there isn't a link sticking.

I spun the tire and looked it over, everything still looks fine. If anything it might be a little tight. There is a section of the chain that isn't as white from the Bel Ray, but I'm sure when I cleaned and lubed it I cover the whole chain well.

P.S. I don't know how my R clip got so jacked up but I have others.

[Alex]

Hard to tell with precision, but it does look like the chain could be a little tight. Not great to run a tight chain, as it can bind up the rear suspension as it hits bumps, and in the worst case, can put enough pressure on the front sprocket to damage the transmission.

[n4mwd]

Originally Posted by Alex

Hard to tell with precision, but it does look like the chain could be a little tight. Not great to run a tight chain, as it can bind up the rear suspension as it hits bumps, and in the worst case, can put enough pressure on the front sprocket to damage the transmission.

And it will. If the chain is too tight, something has to give when you hit a bump. If the chain is new and too tight, it will probably be the transmission that gives and you'll need a new main bearing. Replacing it means splitting the case.

The min/max deflection on the chain while on the center stand should be something like 1.25" to 1.75".

I use a tape measure on the floor to measure chain slack. I lock the tape measure so its hard to pull out, then I hook it over the chain and push it up as far as it goes while pulling the tape measure out. Then I pull the chain down as far as it goes and read the distance at the top of the chain on the tape.

[choneofakind]

Eh, I just give it about 1.5" while it's on a swingarm stand. That way, I'm intentionally giving it a bit more slack than if I were adjusting it on the center stand. A little sloppy is better than a little tight IMHO

[eulark]

Updates!

I have the carb mostly apart. Everything looks rather clean with the exception of the two holes on the intake side of the carb one the actual inlet. I plan on cleaning it all really well and then its back to the bike for checking the timing.

As far as getting it to start, recommendations? Seafoam is in the tank right now. But I'm wondering if i shouldnt squirt a little gas in the cylinders or something. Opinions? I want this running so bad haha.

[n4mwd]

Originally Posted by eulark

Updates!

I have the carb mostly apart. Everything looks rather clean with the exception of the two holes on the intake side of the carb one the actual inlet. I plan on cleaning it all really well and then its back to the bike for checking the timing.

As far as getting it to start, recommendations? Seafoam is in the tank right now. But I'm wondering if i shouldnt squirt a little gas in the cylinders or something. Opinions? I want this running so bad haha.

Cranking with a dry carb is a little rough. You might need to crank it about 30 seconds with the choke full on to get it going. You might could speed up the process by putting a temporary hose on the small port on the petcock and suck on it a little. This will let the gas run into the carb bowls. Then put the regular tube back.

[eulark]

Alright so after another set back, I'm gonna try to get this bugger started again.

After i took the carbs of, I came back two weeks later to give it all a shot and turns out my CDI got filled with water from the rains somehow...so Of course I poured out the water and set the thing in a bag of rice for another week and then hooked it up to the bike. Tried to start, no joy. Checked the spark plug while turning over, no spark. Since it was spitting flames before and now it isnt, the common denominator points to the CDI having gone bad. So now that I picked up a used one on here, I'm giving it a shot tonight. Here's to hoping I get it running tonight.
I just want to see those RPMs rising.

Only other thing I may have an issue with is that while i was trying to start the bike, after a bit the carbs leaked some on the down leaning side (the kickstand side). Is that normal or should i check to be sure the screws are tight? The guy before worked on these carbs and definitely stripped that side's drain screw...

[n4mwd]

Originally Posted by eulark

Only other thing I may have an issue with is that while i was trying to start the bike, after a bit the carbs leaked some on the down leaning side (the kickstand side). Is that normal or should i check to be sure the screws are tight? The guy before worked on these carbs and definitely stripped that side's drain screw...

The carbs might have bad bowl gaskets and/or sticky floats. But if the guy working on them didn't know what he was doing, he might have used RTV on the gaskets which dissolves in gasoline.

[n4mwd]

I should also point out that gasoline causes rubber parts to shrink and stiffen when they dry. So the normal gaskets may be shrunk. If that could be the case, sometimes they will swell back up after being exposed to gasoline again for a few days. Otherwise, you may have to replace them.

[eulark]

Well, the leak is gone for now, the new cdi is on and i have spark.

Oh and it RAN!!!!!!!!!!!! Battery was low so it was with a jumpstart, but it was running!!!!
Still have some gremlins to hunt down but all in all I'm just glad it didn't explode.

Currently now, when i start it, it has to have the choke all the way open and then it ahs no problem idling. If i shut the choke off, the bike dies. Also if i gas it up to 6K RPM it dies. So I'm think the petcock is the place I'm gonna start with. It sat in that tank with old gas that was bright orange when i drained it. So my guess is that its clogging when the carbs pull a lot of gas. (Note that if i throttled quick it would also cut out like it was starving).

So I'm not out of the woods yet, but I'm on the right path at least and very pleased.

Thanks for all your help everyone so far.

Especially to you @n4wmd

Can't wait to get back on two wheels.

[n4mwd]

Sounds like your carb is still plugged up.

You can test the petcock by doing the test procedure in my blog below.

[eulark]

Thanks! I'll test it all out next time I'm working on the bike.
I know one of the diaphragms got bent some, and they look orange.

But I'll pull the carbs off again anyway.

[eulark]

Other things I realized i failed to mention, there wasnt a whole lot of gas in the tank, it has sat in there for about three weeks with seafoam. Also, the diaphragms are bright orange so they might be clogged.

Also, when I had it running, it was only running with the choke fully on. When i turned it off, it would last anywhere from ten seconds to dying instantly (I tried multiple times)
Sorry if some of this is repeat info. Part of the reason for this thread is to help me remember what I'm doing haha.

[n4mwd]

I've never heard of orange diaphragms. All the ones I've seen have been black. But definitely, the carb sounds bad.

[eulark]

Haha that's my point. When I first put the motor back on the bike, the bike had been sitting for a year. I never drained the tank and the lining inside was coming apart so the gas was rusting the tank. When I drained it the gas was bright orange. And it stained the diaphragms. It could also be the lining inside causing an issue. I got most of the loose stuff out but it's a pain in the bit to get out.

[n4mwd]

Originally Posted by eulark

Haha that's my point. When I first put the motor back on the bike, the bike had been sitting for a year. I never drained the tank and the lining inside was coming apart so the gas was rusting the tank. When I drained it the gas was bright orange. And it stained the diaphragms. It could also be the lining inside causing an issue. I got most of the loose stuff out but it's a pain in the bit to get out.

The diaphragms in your carburetor should not be coming into contact with gasoline. It can ruin them.

The tanks don't come with liners so if it had one, it was one that someone put the sealer in before you got it. In that case, its possible they sealed your petcock too. Its probably not a bad Idea to remove it and check it out.

[eulark]

Ah there's the miscommunication. Haha. I'm referring to the diaphragms of the petcock as they are referred to in my manual I think. The filters inside the tank.

And I was wondering about the sealer being stock or not. It's a major annoyance to be sure.



***Edit*** Maybe im wrong on what the name of those things are. Im just referring to the two filters that stick into the tank. One tall and one short.

[jayman87]

There is a diaphragm in the petcock but I think you're referring to your main and reserve fuel lines. I think they start out clear but I wouldn't be surprised if they turned orange from being soaked in gas. I don't think they have anything to do with filtering though. You may have a clog, but I differ to the experts.

Edit: Fuel Filter Installation from ninja250.org

[eulark]

http://faq.ninja250.org/wiki/File:Ninja250petcock.jpg

The section on the left of the picture I'm worried either are clogged with rust, or even the laminate inside coming undone and causing problems. I'll probably go fishing for that stuff again. haha

[eulark]

Pulled the carbs since I couldnt get any results other than what I got the other night.

I have them apart right now and have pulled the main jets and the pilot jets along with the carb diaphragms, floats and idle screws. I've come to a few conclusions.

1. Apparently while i was thinking that the idle was set properly, and the idle screws were so, the speed control thingy from iunder the carb was not actually making contact with the bracket that controls the flow. So that would explain the dying when take the choke off.

2. All my jets are immaculate. But for safety I'm going to clean them with carb cleaner along with various parts of the carbs.

3. I may have forgotten to back out the main jets 2.5 turns. Not sure, but that would make sense to me that i Forgot.

So I'm going to finish cleaning these and try again soon on starting the bike. I am also wondering if it doesnt have to do with the fact that my air filter is not in the best of shape.

Something i did notice when I started it yesterday, with the choke on (Pulled all the way to the back of the bike), I could take it all the way to 8krpms and beyond, but I couldnt do so without the choke.

[eulark]

Hey All,

Just as an update, it is now running! I'm going to do a few more things, but once that is done, I'll be back on the road.

Things left to do:

1. New oil and filter. The bottom end is still a slight mystery to me since i didnt pull it apart, so I'm going to change out the oil and filter just to get as clean of a motor as possible.

2. New air filter since mine is completely coming apart for some reason. Like disengrating.

3. Carb float bowls are leaking at the seal, so I'm going to go ahead and order some new gaskets and redo that.

Any real danger with this? Once the motor is at operating temp, the drops dry up immediately.

4. Replace battery since it doesnt seem to want to hold a charge.

So I did take it for a ride yesterday. Lots of fun around the neighbor hood. All the gears are working and the clutch is set properly. Brakes stop the bike. Both accel and decel work. Bike sounds good. Once i have it on the road, im going to take it to a mechanic to get him to go over it with a fine tooth comb just to be sure all is good. Then I'm on the road for good. Woohoo!

[n4mwd]

Glad you finally got it going. You've been working on it for almost a year.

The carb bowl gaskets will shrink if they have been exposed to gasoline and then let dry. So they shrunk. They will re-inflate upon exposure to gasoline. Its best to soak them overnight in gasoline, but they'll eventually swell back up if you just install them, but you'll have a leak in the mean time.

[eulark]

Oh thats right. I forgot about that. Well I guess the gaskets can wait. I'll see how they are doing later next week when i ride again.

And it has been over a year now. If felt soo great to feel that kick in the seat of your pants again.

Thanks for all the support by they way man. I really couldn't have done this without your help. If you are ever in the NC coast area let me know.

[n4mwd]

Pretty much the only time you need new carb gaskets is if you damaged them pulling it apart.

At some point in the future I plan to go to the Dragon, but that's at the other end of the state. Also, I may be visiting some friends in Charlotte.

[eulark]

Well I'm always up in the Asheville area since the gf's parents live there. It's not too far from Dragon haha.


Question in general. What happens when the cam chain goes? If you are in gear, does the rear wheel lock up?

[n4mwd]

Originally Posted by eulark

Well I'm always up in the Asheville area since the gf's parents live there. It's not too far from Dragon haha.


Question in general. What happens when the cam chain goes? If you are in gear, does the rear wheel lock up?

Probably wont lock the rear wheel, but the engine will be destroyed.

[eulark]

I see.

By the way, I'm placing an order for various parts i need, and something i need are the front upper fairing bolts. I'm ordering from cheapcycleparts because they also have the Regular OEM air filter since I just discovered mine to be disintegrating. Are all 4 bolts that go through the tank side of the fairing the same? I dont want to punch a hole in my tank for sure.

[n4mwd]

The tank bolts are all the same length, but short enough that the top ones don't hit the tank. In any case, only use a hand allen wrench when tightening them. That way you are less likely to puncture the tank.