Hey, just got it back togrther again...and check the plug after about 30 min., the plug looks the same as when I put it in new. I have a 310 jet and the clip is all the way at the bottom. I don't know what to do. I don't want to burn a hole in the piston again. I'm going to call Rick back, and see what he says to do. If someone can help that would be great.

 

This may have been asked before ,but did you look for an air leak ? Also make sure the crankcase drain plug is in and tight.Also another place to look for a problem is the bottom cases next to the clutch side just below the cylinder .They have been known to crack in this area,this would also cause a lean condition.What plug are you running ?

 

About the air leak, when I just had my pipe and K&N and jet it ran fine. Would an air leak cause a problem then? The plug i'm running is a denso w24esr-u. This is the plug I ran before the head work and the porting was done.

 

ive never even heard of that plug,id try putting in a ngk

 

yes an air leak would do that, your getting way to much air and not enough fuel to go with it...


When its lean your getting more air then fuel thus making it run hotter. If your running that big of a jet with the carb settings there has got to be an air leak somewhere, carb boot,head gasket etc... don't know much about the 400s but you need to check that thing over well...

 

I'm going to try to go back with the stock plug which is a BR80S...But I don't know who makes them. Rick said that what they come with stock. I wanted a NGK but know one around here carries them, that I can find.

 

I guess what I was trying to say is if I had a air leak it would have caused a problem when I just had the pipe and Jet, & the K&N right...or wrong?[img]i/expressions/face-icon-small-confused.gif[/img] I'm going to check the compression tomorrow, Rick said it should be about 145 to 150. If it has too much would this cause a problem?

 

If the compression was low it would be hard to start. Is it hard to start?

 

No it starts good, I'm worried about it being to high...would this cause a problem? (being to high)

 

You might take it to a dealer and have them do a vacuum test. If the vacuum goes down then you have a leak somewhere. I'm gonna do this tommorow on mine. I have bad throttle response and weird plug readings. I think that it may be in the carb boot cause it's pretty cracked and one of the cracks could have gone all the way through. Just something to think about. I hope all works out for ya.