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no gearbox oil after a new rebuild ?

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hi all i just rebuilt the top and bottom end on my kx 250 04 well i never some 1 did it for me..when i got it back i put some gearbox oil in started it up for the first time and it was smoking so bad i couldnt see down the street i thought it would be some excess oil burning in the engine but when i looked at the gearbox oil level there was no oil left in it...can the gearbox oil leak into the engine and burn like that ?? PLEASE HELP !!

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crankcase seals gone or pinched during install,right side is the one that can suck in the oil.Worst part is you have to split the case again to change it.I actually folded the lip of the seal during my rebuild but caught it before I had it together and was able to fix it.

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You have to split the cases again to change the seal. It is easy to roll the lip on the seal when you put the crank in and I have done it too.

Ed

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yes camarokid88 i put it in myself the day i got it back then started it up for about 2 mins and it was ok.. then it was stood in my garage for about 1 week and i got the bike out today and started it up to make sure it was ok for tomorrow and it was smokin a stupid amount then when i looked all the gearbox oil was gone

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could be improper sealed case halves too.if you ran it first and was ok then laid it up for a week and it was dry when you tried it again.Its possible the oil leaked into the crankcase from a bad case half seal.I don't know how much it would take to hydrolock the engine though,was it hard to kick?

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are you sure about splitting the cases, you don't have to on a yamaha, not sure abot kawi though.

removing the seal is pretty easy on every bike ever made..... except kawasaki :lol:. alittle puzzling why they would make the seal like that. whats even more puzzling beyond the brains ability to comprehend is why they thought it was a good idea and continued to do it for years and years and years :):banghead::cheers:

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removing the seal is pretty easy on every bike ever made..... except kawasaki :lol:. alittle puzzling why they would make the seal like that. whats even more puzzling beyond the brains ability to comprehend is why they thought it was a good idea and continued to do it for years and years and years :):banghead::cheers:

im going to mill all my cases next time they are apart for this reason

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Without the tabs you run the risk of a backfire blowing out your seals

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Without the tabs you run the risk of a backfire blowing out your seals

i know, which is why i have never done it, but someone on here (clyde?) has done it, and has ran like that for a while with 0 issues. i figure id machine a little retainer bolt hole in there like they do on the bearing in the tranny anyway. how do the other manufacturers do it? and for the record, none of my smokers has ever backfired in 500+hrs of riding, the drz has once or twice

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removing the seal is pretty easy on every bike ever made..... except kawasaki :lol:. alittle puzzling why they would make the seal like that. whats even more puzzling beyond the brains ability to comprehend is why they thought it was a good idea and continued to do it for years and years and years :):banghead::cheers:

Because if your main seals are bad, your bearings should be replaced as well. Makes sense to me, anyway.

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I have tried it and it is working fine. Sean most other manufacturers just use friction ot the fit to hold them in, I also use loctite bearing retainer to glue them in. I have only done it to one of my motors though.

Ed

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I have tried it and it is working fine. Sean most other manufacturers just use friction ot the fit to hold them in, I also use loctite bearing retainer to glue them in. I have only done it to one of my motors though.

Ed

thought it was you, good deal.

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only time mine has backfired is when I'm trying to kick it over from cold,other than that it never does.Alil retainer would solve that issue anyways but like was posted when the seals go its probably a good idea to do the mains anyways.In cases of a torn seal then it would be very easy if the tabs were gone.If it were me I would cut a groove where the tabs were and use a snap ring to hold them in.

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thanks guys...droped the bike off with the lad who rebuilt it today hes gonna pull it apart again..

camarokid88 i know you wernt trying to be funny mate lol.

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Because if your main seals are bad, your bearings should be replaced as well. Makes sense to me, anyway.

the OP just rebuilt the bottom end. if i understand correct the seal lip may have been damaged in the process. now the whole engine has to come out of the bike and be split again, the main bearings will also need to come back out. not sure how he plans to remove the bearings but they could be damaged also. big hassle for such a small problem. is there no interference fit on the seal ?? machining them tabs off seems like a legit idea.

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the OP just rebuilt the bottom end. if i understand correct the seal lip may have been damaged in the process. now the whole engine has to come out of the bike and be split again, the main bearings will also need to come back out. not sure how he plans to remove the bearings but they could be damaged also. big hassle for such a small problem. is there no interference fit on the seal ?? machining them tabs off seems like a legit idea.

my exact point. it wouldnt be benificial during rebuilds, but for a mistake like this or an early failure it sure beats the headache.

and yes they are interference fit, they just have a tabs as well

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