I found the culprit! Boys, check your carb slides.

how does head and cylinder look after munching on chunks of carb slide.

Can you post pics?

I'd like to see what your talking about...

As for pictures, I'll get some this evening and I'll post them tomorrow.

As for the combustion chamber, it still look real good. No scoring on the cylinder walls and the piston nor head look as though any damage occured.


Went home during lunch, and sat there looking at the bike. I picked up the carb, and looked at it, and sure enough, the carb plate that fits on the front of the slide is cracked, and there are pieces of it missing.

This is injestion #2 for my bike. About 300 miles into my ownership of this bike, that exact same thing happened. I replaced the that plate from Sudco. I did not dream that could happen again so fast, but it has.

I strongly recommend good shoes and checking your carb slide plates.

A little happier about the situation,


This is the carb plate that has now failed on my bike twice.

Notice the chunk missing on the left, and if you look very closely, you can see a crack that runs up the right side almost to the top. That side was very close to breaking off as well.



isn't this a known problem with only the older bikes?


Your pics not showing up for some reason.

Can you e-mail it to me?


I was under the impression that the older (mine is a 98) carb slide plates were identified as a weak item, and there was a new slide plate being used. Thing is, I thought that I got one of the new slides!?!

Will slap another one in and see how long it lasts....


Check to make sure the throttle stop is the correct length. I've heard that removal of the stop or one that is too short may cause the slide to slap inside the carb which could lead to cracks. Don't know if this is true but search the forum on "cracked slide" or something similar like "throttle stop" and you may and you may find infor on what is causing this. But you probably already have. Are you moving up to a WR470 while it's apart?

I think that my throttle stop might be too short. As I modulate the carb, the slide is all the way to the top, yet the carb is not being stopped by the throttle stop.

It looks like I need to add material to the throttle stop. Can this be done, or, do I need to buy another and re-cut it down?

Hey Mike! Seems like I was just dealing with this, huh! No, no 470 is planned, but that would be nice! Alaskan Amber, right?


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