Checking crank seals

I was asked the other day "how are your crank seals?" I dunno. They're still there.

How DO you check crank seals?

Leakdown test.

Like on Family Fued TV Show, "good answer", "good answer". :lol:

A leakdown test will be a good indicator.

Tool?

What do you recommend?

On the stator side you can pull off the side cover start the bike and squeart carb clean and if the idale goes up you have a bad crank seal on that side if oil in the tranny is getting used up you have a bad crank seal on that side

On the stator side you can pull off the side cover start the bike and squeart carb clean and if the idale goes up you have a bad crank seal on that side if oil in the tranny is getting used up you have a bad crank seal on that side

No oil being used. I'll check the stator side.

I just changed the piston and someone thought it showed signs of debris- dirt, maybe. Suggested I look at the crank seals, but also suggested the air filter. I clean my air filters every ride, but they're over a year old and maybe the foam's worn out a little. I have new filters on the way. Didn't find any dirt in the airboot or in the carb. The cylinder was replated- maybe it was just a little leftover stuff I didn't get cleaned out. Dunno. Bike was running fine- this was just scheduled maintenance to get a feel for how it was wearing.

Here are the piston shots. This is 17 hours in a 144:

DSC02551.jpg

DSC02548.jpg

DSC02549.jpg

what kind of premix are you using?

what kind of premix are you using?

Yamalube 32:1

Did you hone out the cyclinder and cleaned it good before you used it?

$280!!!! That's a lot. Got one I can rent?

Just drive your bike over, and we can just use it here. :lol:

Are you thinking you are running a little rich? (your piston top being black instead of chocolate brown, or at least more centered burn pattern with 17 hours)

Do you have the airbox to airbox boot junction sealed with some sealant?

Are you thinking you are running a little rich? (your piston top being black instead of chocolate brown, or at least more centered burn pattern with 17 hours)

Do you have the airbox to airbox boot junction sealed with some sealant?

Yes- I'm positive I'm a little rich. Just dropped the main jet 1. Might go 2 later in the summer as it warms up.

I have not sealed the airbox junction. I'll go do that.

EDIT: sealed. Removed the boot and sealed everything w/ silicone.

Good job. They love to suck dust and dirt through the little cracks.

I didn't find any dirt or dust under the seal, but that doesn't mean anything- it could've just sucked it all in!

Ha Ha Ha Lol

I'll tell you what I do notice, though, is a dusty oil smear right around the air screw. I don't know if you have dust in Alabama :lol: but that dust is collecting for a reason and that reason is usually an oil leak of some sort. I smeared a little gasket sealer on the air screw threads to see if that'll help, but it's something I'll keep an eye on.

Any ideas there?

Here's some dust for ya (see 1:12-1:15):

Riding the KX144

I have it on mine, too. I wonder about any o-ring??

I have it on mine, too. I wonder about any o-ring??

There's no o-ring there- you'd have to add one. Oh well, if you've got it, too.... I'll see how the gasket sealer works.

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!


Register a new account

Sign in

Already have an account? Sign in here.


Sign In Now