Crank Seals or Not??

[3 stroke]

I have a 2000 Honda CR125 that when started needs to "clear it's throat" after idling by holding the gas open 3/4 throttle to fully pinned until it clears out and starts to sound crisp. I thought this was a jetting issue and posted a few threads over on the 2 Stroke Honda board, but after adding a leaner pilot, main, and moving up the needle clip it made it idle better, but didn't clear up the problem of what I guess could be considered "loading up".
I spoke to a few people who said they had this same problem and it was the result of bad crank seals. I called my local Honda mechanic to ask what he thought about the idea of it being the crank seals, and he told me if it was the crank seals on the "wet side" that it would have sucked all the gear oil into the crank case(I just changed my gear oil and it was not quite up to the check bolt, but it was not much lower). He also said if it was the seal on the ignition side that my bike would not idle as good as it does(My bike idles, but varies in RPM a lot and usually starts revving real high for a while, until I blip the throttle). Is he right with what he is saying? He also said the 15-20 hours I put on the top end is still considered pretty fresh(he may have said that since he knows I am just learning to ride). Any help on this matter is fully appreciated!! Thanks!!

[Bad Dos]

What is the color of your plug at idle?

[KTM250rm393]

GO buy some ATF Type F fluid and put it in the tranny and start your bike and ride it. If you get a ton of white smoke, its your crankseal on the tranny side.

[MotoMan]

Hmmm, I was leaning toward crank seals until you said your bike will start to wind up when idleing. Try spraying some wd40 around the top end of your bike and around the carb and see if the engine speeds up or not. It COULD be an air leak as well.

Also, when you rev the bike to clear it out, does it smoke very bad, if so what color is the smoke, traditional 2 stroke blue or is it a whiter color?

[Faded]

Originally posted by MotoMan
Hmmm, I was leaning toward crank seals until you said your bike will start to wind up when idleing. . . .It COULD be an air leak as well.

If it's the ignition side crank seal that is bad then it will allow air into the crank case effectively leaning out the mixture and causing a high-idle condition. For as cheap as they are I would replace them just so you could rule them out.

[MotoMan]

Good thinking Faded....as always.

[3 stroke]

Bad Dos - The plug is a good brown color after running the bike for a little while.

KTM250rm393 - Can doing this cause any problems with the trans oil? For instance, after I add the ATF should I then change my gear oil?

MotoMan - I will try the WD-40 trick you mentioned. It is usally soaked in WD-40 anyway since after I clean it I soak it in WD-40 and don't wipe it off...to prevent rust or other corrosion.

Faded - I am probably going to replace the crank seals...just need to find a flywheel puller, impact wrench, and torque wrench. Probably things I should have anyway.

Thanks everyone for your help. Anymore suggestions, I am all ears.

[Blitz393]

everything that could be said already has been. only when you said

"KTM250rm393 - Can doing this cause any problems with the trans oil? For instance, after I add the ATF should I then change my gear oil?"

he means switch your current tranny oil with the ATF. you should change your transmission oil pretty often (i do it every 3-4 rides, or every 8-10 hours of accumulated ride time) it's cheap and it keeps your clutch nice and clean.

Rob