Crank Seal / Compression Test / Troubleshooting

[LiftdT4R]

Ok, on my 2001, the right side is running extremely rich, smoke is way to thick. The carbs are setup perfect,a nd synched, 260 mains, 25 pilots, needle on middle clip, air screws 1.25 turns out, jetted for FMF Gnarlies, airbox w/lid at 70* and 0 feet. Stock cylinders and head. TORS was removed, and new idle screws were tapped.

 

I thought it might be crank seals, since I found a lot of people with the same problems. Only problem is, after letting it run for about an hour, mostly at idle, and a little revving, there was no change in the tranny fluid.

 

I compression tested it, and both cylinders and they both made 125 PSI give or take 1 or 2 PSI.

 

So my first question would be, if a crank seal was shot, wouldnt it compression test way too low?

 

I also tried to switch the coils from side to side, and let it run for aprox. 15min. No change, tried new plugs also, Im running BR8EGs, both sides. The carbs are clean, and there was new gas just put into it. I think it might be a very slow crank leak, and the compression test might be "missing" it.

 

My next stop will be a leakdown test, unless I missed something. Any info would be greatly appreciated. As always, I owe you guys a lot for all the help so far.

Edited September 28, 2006 by LiftdT4R

[Bansh-eman]

Ok, on my 2001, the right side is running extremely rich, smoke is way to thick. The carbs are setup perfect,a nd synched, 260 mains, 25 pilots, needle on middle clip, air screws 1.25 turns out, jetted for FMF Gnarlies, airbox w/lid at 70* and 0 feet. Stock cylinders and head. TORS was removed, and new idle screws were tapped.

 

I thought it might be crank seals, since I found a lot of people with the same problems. Only problem is, after letting it run for about an hour, mostly at idle, and a little revving, there was no change in the tranny fluid.

 

I compression tested it, and both cylinders and they both made 125 PSI give or take 1 or 2 PSI.

 

So my first question would be, if a crank seal was shot, wouldnt it compression test way too low?

 

I also tried to switch the coils from side to side, and let it run for aprox. 15min. No change, tried new plugs also, Im running BR8EGs, both sides. The carbs are clean, and there was new gas just put into it. I think it might be a very slow crank leak, and the compression test might be "missing" it.

 

My next stop will be a leakdown test, unless I missed something. Any info would be greatly appreciated. As always, I owe you guys a lot for all the help so far.

 

do a leak down test and get some water and soap and spray it around all your seals and gaskets if your leaking it will bubble at the leak... but if your running rich you shouldnt have a leak ... leaks casue you to run lean. and its rich at idle right? check your pilots and make sure they match... if you can get a feeler gauge and test them rather then going with the stamped numbers... also check your idle screws make sure they are for sure at the same setting.. i had this problem and my screws where like 20 clicks off from each other...

[LiftdT4R]

do a leak down test and get some water and soap and spray it around all your seals and gaskets if your leaking it will bubble at the leak... but if your running rich you shouldnt have a leak ... leaks casue you to run lean. and its rich at idle right? check your pilots and make sure they match... if you can get a feeler gauge and test them rather then going with the stamped numbers... also check your idle screws make sure they are for sure at the same setting.. i had this problem and my screws where like 20 clicks off from each other...

That's what I figured about the leakdown test. I'm kinda fucked up on the pilots and jets, so I'm gonna go back and look over the carbs. The pilots were both stamped 35, and the mains were both stamped 260, but one main came from my old carbs, and one main came from a jet kit. Both pilots came from my old set of carbs. One would think they would be accurate, but who knows. I'm gonna try to check the idle too, that might do the trick. Thanks for the info,

 

Still wondering though if the crank seals would affect a compression test? I think they would.

[Bansh-eman]

if your jets are not from the same kit chances are that they are not the same... as far as the crank seal im not 100% but i dont think it effects the compression test casue thats the pressure on the top of the pistons at the domes... thats why you have to do a leak down test to see if you have a bottom end leak. but like i said before you wouldnt be running rich if you have a leak you would be running lean. 125 for a stock motor im assuming? thats not too bad ...

[LiftdT4R]

Cool man thanks for the info. I'm gonna try to find 2 matching jets from the same kit. I didn't think they would be this far off, but hey, who knows.

 

I suspected it was the right side crank seal, because that's the only kind of leak that would make it run rich, but the tranny oil hasn't dropped.

 

The motor is stock. I grabbed a couple of pics, to maybe try to help, also, the right side looks almost lean now, there is hardly any smoke. On the right side, there is an ok amount of smoke at idle, but if I rev it, and let off, smoke just purs out, like a fog machine. Here's some pics:

 

At idle:

 

 

While revving, about mid way:

 

 

I'm lost on this one, aside from the mains being from different kits, everything else seems to be setup right on the carbs, I checked idle screws and both are 2.25 turns out, the pilot screws are 1.25 turns out, with 25 pilots. As always, thanks guys!

Edited September 28, 2006 by LiftdT4R

[Bansh-eman]

Cool man thanks for the info. I'm gonna try to find 2 matching jets from the same kit. I didn't think they would be this far off, but hey, who knows.

 

I suspected it was the right side crank seal, because that's the only kind of leak that would make it run rich, but the tranny oil hasn't dropped.

 

The motor is stock. I grabbed a couple of pics, to maybe try to help, also, the right side looks almost lean now, there is hardly any smoke. On the right side, there is an ok amount of smoke at idle, but if I rev it, and let off, smoke just purs out, like a fog machine. Here's some pics:

 

At idle:

 

 

While revving, about mid way:

 

 

I'm lost on this one, aside from the mains being from different kits, everything else seems to be setup right on the carbs, I checked idle screws and both are 2.25 turns out, the pilot screws are 1.25 turns out, with 25 pilots. As always, thanks guys!

 

it might also be your head leaking and letting coolant in your jugs and smoking that side as well....as far as your right seal leaking ... im not 100% on this either so if someone knows plz chime in but the pressure from the crank case should push fuild away from the seal instead of sucking it in ???? but i could be backwards....

[LiftdT4R]

it might also be your head leaking and letting coolant in your jugs and smoking that side as well....as far as your right seal leaking ... im not 100% on this either so if someone knows plz chime in but the pressure from the crank case should push fuild away from the seal instead of sucking it in ???? but i could be backwards....

People in the past have reported it suckin in the tranny fluid. I'm thinking it's gotta be somehwre in the carbs, because everything was fine before I put the aibox in, and went to smaller jets. The carbs drive me fucking crazy on these bikes. I just can never fucking get them setup right. I have read the FAQ, and the Clymers about a million times, and I never had a problem with a single carb on any of my other bikes, but these things are just such a bitch.

 

I just can't see it being the carbs because they are synched as far as I can tell, and they clean as new.

 

If anyone knows whether a compression test will identify a bad crank seal, hit me up. Or else I think I'll be leakdown testing it shortly.

 

I really thought about bringing this back to the stealership earlier today, but I hate dealing with their shit, and high ass prices, but hey, know I know why they charge so much to work on themn, it's really a pain in the ass!

[Bansh-eman]

People in the past have reported it suckin in the tranny fluid. I'm thinking it's gotta be somehwre in the carbs, because everything was fine before I put the aibox in, and went to smaller jets. The carbs drive me fucking crazy on these bikes. I just can never fucking get them setup right. I have read the FAQ, and the Clymers about a million times, and I never had a problem with a single carb on any of my other bikes, but these things are just such a bitch.

 

I just can't see it being the carbs because they are synched as far as I can tell, and they clean as new.

 

If anyone knows whether a compression test will identify a bad crank seal, hit me up. Or else I think I'll be leakdown testing it shortly.

 

I really thought about bringing this back to the stealership earlier today, but I hate dealing with their shit, and high ass prices, but hey, know I know why they charge so much to work on themn, it's really a pain in the ass!

 

if you dont have a sync tool your more then likely not on... ask Polish... he swore that his was right becasue he did his for over an hour but when he used my tool his was WAY off

[dirtyernie52]

compression test will not tell you if you have a bad seal!!!

 

you will need to do a leak down test to find that out. do a search on here and you will find out all you need to know about leak down tests. hope this helps

[dajogejr]

but when he used my tool his was WAY off

 

He...uh...used your tool? Um...ok?

 

:yelrotflmao:

 

Sorry...banshman...I just had to... :biggrin:

 

Call Jeff @ FAST for the sync tool. It's used to sync carbs on the old VW motors....

PM Machwon for a premade leakdown kit...or, you can build your own if you have the time and resources.

 

Also...clean the bejezus out of the carbs too, making sure none of the passages are clogged or dirty...

[LiftdT4R]

compression test will not tell you if you have a bad seal!!!

 

you will need to do a leak down test to find that out. do a search on here and you will find out all you need to know about leak down tests. hope this helps

Thanks man, My next step is a leakdown test. I'm just trying to go back over the carbs, because my tranny oil is till full after 4 or 5 hours worth of riding like this(yeah, I know it's not good). My mains are both the same now, 260s, from the same kit, but I must be funckin' missing something easy. Although, the crank seals are original from 02, and I bought the bike used, so, you never know I guess. This is drivin' me nuts though!

[boonman]

You may not see much of a change in tranny fluid if you have a small leak on that crank seal. Now, the next test, what does the right side exhaust smell like? And what type of oil do you run in the tranny? If you run gear oil, and the cranks seal is leaking, it will smell HORRENDOUS. Also, what does the plug look like on the right side? Is it really dark? If it is, and the other side isn't really dark, I would suspect a crank seal. :ninja:

[LiftdT4R]

Thanks for the info. I do use PJ1 2 stroke gear oil, but it just smells like a regular old 2 stroke. This was the same bike from my rides of shame thread, so it was rolled pretty bad, and that's when the rich right side started happeneing. I probably should have mentioned that earlier :: Thanks again for all the info, here is what I came up with so far

 

I'm thinking it could be the float height is fucked up the right side(something stupid as hell, that I didn't even think about until now). I'm gonna go on that tomorrow, and see what I get from there. ust to double check, it should be about 20-22mm right? I got that from Clymer, but I didn'tknow if it would differ for my mods. The carbs don't leak gas ornayhting, but I think it might be high enough where its suckin too much gas, but not enough to overflow.

 

Also, I wanna check the reeds out again. They looked perfect last time I had it part, 1 week ago, but hey, you never know I guess. I PMed Jeff about the carb synch tool today, and I'm waiting to hear back from him so I can order it. If this doesnt work, then it's gonna be leakdown time.

[woodro77]

i had a bad crank seal on right side , my tranny was getting pressure and pissing out the over flow , pressure inside the crank pushed out the crank seal and into the tranny ,

[LiftdT4R]

Ok, I'm still having the same trouble, and I have had the carbs apart a few times now. I guess I should be a little more complete with my story.

 

The bike ran fine, and had the same amount of smoke out of both sides when I got it. It had a 2 into 1 open filter, and reed spacers, with no airbox. And I do mostly trails and decided to put back on the stock air box. I had everything apart, took off the reed spacers, and put in new reed gaskets, and put the original boots back on. When I went to take the cap off the right side carb, I did not notice the little allen screw was still in, and it stripped the threads for the cap.

 

I replaced the carb with another spare that I had. I put the exact same size 260 jets in, with 25 pilots, air screws 1.25 turns out, and the floats are at 20 mm. Both carbs are stock, and as clean as can be, originally I did have 260 jets from different sets in, but now they are from the same set.

 

After all this work is when I started to have trouble. I still can't figure it out for the life of me. I thought it might be a crank seal, but the tranny oil does not change even after 4 hours of riding. Compression test also pulls 125 PSI on both cylinders. The pics are above, but basically when it idles the right side smoke more but not a heck of a lot. When I get on the throttle, still more on the right side. When I let off, the smoke just billows out. If I hold my hand up to the pipe while accelerating, I will have specs of oil all over my hand afetr a few second.

 

I am still completely lost, and at my wit's end with this. I really don't have the loot to bring this to the stealer, and I always work on my own shit, this is the first major thing I have run into that I am completely dumbfounded by. My only 2 things left that I could think of would be

 

- Fuel Valve? Maybe the fuel valve in the carb is bad, and it just lets gas in even when the floats are up?

-Crank Seal? If I can't figure out anything else, I'll tear the cases apart, and check it just for heck of it.

 

Other then that, nothing. Any help would be greatly appreciated, because I am not really sure to go from here. Thanks again, the pics of the exhaustare still above, and it has all the mods listed in my sig under the 2002.(it has a bent stem, and bent a-arms, but this problem was before my crash, and it hasnt changed since)