KDXRIDER.NET

My KDX200 Hybrid has a 2005 motor that is on the original piston. When I was building the hybrid I looked in the exhaust port and there was considerable blow-by all the way around that I could see.

At the race last weekend it started running kind of bad. It refused to idle. If I let the revs drop it would die, but I would just pull in the clutch and then let it out to get it going again without having to kickstart it. I assumed that it was from so much water splashing in the KX's mx-style airbox and soaking the filter. I took the carb off today to check it and there had definately been some water and dirt getting in past the air filter. There was alittle bit of grit in the carb, I couldn't find any as far as the reeds. I cleaned everything really good and put it back together, but it still dies when I let off the gas (won't idle).

I did a compression check and it read 120. How low is that for this bike? Do you think a new top end is in order?

I think 120 is a little low.... Need to Wiseco it!

Do you have a previous compression reading?

I used to get 150-160 so it sounds a little low to me too.

Finding the grit isn't comforting. Myself, I'd be interested in taking the cylinder off to peek around. And change that piston like the man says.

My 200 after a piston will get about 152 with everything cleaned up.