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Gas smell in trans oil

Posted: 04:43 pm Apr 01 2018
by Mav
Since I haven't had my 2000 KDX220 long, I'm still making my way through everything. This weekend was fork oil and seals (the oil was BAD), coolant flush and fill with engine ice, and trans oil. When I drained the oil, I noticed that it kinda looked like the oil from our drag car, so I put some on my fingers and smelled it, it smells like it has a little gas in it.
I have flooded it a few times and forgot to turn the petcock off. I'm wondering if this is connected to my issue of not being able to idle, adjust idle, and why it takes several kicks to start once warmed up vs 1 or 2 kicks when the engine is cold.
My buddy said his yz250 was similar issues when he needed a topend.

Re: Gas smell in trans oil

Posted: 07:33 pm Apr 01 2018
by ohgood
there is no easy path for fuel to get into the transmission oil. if the combustion chamber was flooded completely, it would have to blow a seal to get into the trans

Re: Gas smell in trans oil

Posted: 08:08 pm Apr 01 2018
by Mav
that's what I thought. I read about porous castings, was that year specific?
Or maybe the fuel smell was just in my head because i was in my garage.

Re: Gas smell in trans oil

Posted: 09:36 pm Apr 01 2018
by ohgood
Mav wrote:that's what I thought. I read about porous castings, was that year specific?
Or maybe the fuel smell was just in my head because i was in my garage.
no idea about it being year specific.

I would pull the side covers and fill the cylinder with premix to check for seepage

Re: Gas smell in trans oil

Posted: 09:56 pm Apr 01 2018
by Mav
That's a good idea, I hadn't thought of that. Thanks

Re: Gas smell in trans oil

Posted: 09:57 pm Apr 01 2018
by Mav
I really need to do a compression test also, but I can't find my tester since the move. Guess it's time to buy another.

Re: Gas smell in trans oil

Posted: 04:40 am Apr 02 2018
by Timtee
Mav wrote:I really need to do a compression test also
Pressure and vacuum as well. Seals may leak under one condition but not the other.

Re: Gas smell in trans oil

Posted: 11:58 am Apr 02 2018
by Mav
Will do

Re: Gas smell in trans oil

Posted: 02:29 pm Apr 02 2018
by david
I would start with just a trans fluid change and then re-check after riding it some.

Quick story.....When I first got the old 175, the petcock had been left on and the trans was full of gas. It also would not start in this condition. I didn't know the trans was full of gas until I wore my self out trying to get it started and the gave up and decided to do some regular maintenance on it. After I changed the trans oil, it fired right up and it ran well for years. Didn't use any trans oil either.

Re: Gas smell in trans oil

Posted: 04:10 pm Apr 02 2018
by bufftester
The only way for fuel to make it into your tranny is through the crank seal. Leakdown test will tell you if they are bad.

Re: Gas smell in trans oil

Posted: 05:50 pm Apr 02 2018
by Mav
Pulled stator cover to get ready for leak down. There's about 1-2 tablespoons of fluid that smells like old gas, but nothing like the 100LL that I run.
Compression test showed 150psi

Re: Gas smell in trans oil

Posted: 07:18 am Apr 03 2018
by Julien D
Compression test will not show leaky crank seals. That requires a leakdown test. However, if you have fuel mix in the stator, and fuel mix in the trans, there is little doubt that your crank seals are shot.

Re: Gas smell in trans oil

Posted: 05:37 pm Apr 03 2018
by Mav
Can't find my leak down tester and don't really feel like piecing one together again, so I will have to order one and wait for it to come in.