PDA

View Full Version : HELP, 400ex engine problem



400ex2072
06-02-2005, 08:06 AM
Hey guys, this should be my last post on getting this thing dialed in, and I appreciate the help Ive got so far. Heres the situation...

I got my engine rebuilt totally, and it starts up and idles just fine. Problem is, when I took it for a test ride, it doesnt pull on the top end. I can only get about 1/2 throttle out of each gear. It'ss still rev out, just wont put power to the ground past 1/2 throttle. I adjusted my valves cold, but never adjusted them warm yet. I know I need to do that, but before I do, could that be causing the problem? I lined up the valve timing perfect, so I dont think thats the problem.

I added a 12.5:1 piston in my engine, so Im wondering if theres anything special Im supposed to do with this. I set it up with all the stock settings. Am I supposed to retard or advance any valve or ignition timing or do any other out of the ordinary setup with a high compression piston? Im hoping its just the valve lash, but PLEASE let me know what you think. Im a half step away from getting this thing dialed in finally, thanks.

400exrider707
06-02-2005, 08:32 AM
You are supposed to adjust those valves cold. What octane gas are you running? Are the mods in your sig for the bike your asking about? If its revving out but now power is getting put down is it possible that your clutch is slipping?

TC426EX
06-02-2005, 08:41 AM
I was thinking the same thing about the clutch slipping, but if it was slipping, wouldnt it just not put power to the ground period, and not just at high rpm?

Wheres Wilkin on this one?

duke416ex
06-02-2005, 09:13 AM
If the clutches are slipping, they can slip throughout the rpm if they are bad enough, but they will be more noticable in higher rpms and in higher gears. What does it do in fifth? The clutches are gonna slip more when under a load then when just taking off. Does it just kinda get to a point where it just quits gaining or does it just gradually die off?

400ex2072
06-02-2005, 10:22 AM
I thought about it being the clutch as well. I noticed when I put the side cover on I had to adjust my clutch more than before. I know I have the clutch installed in the case properly, so Im wondering if there is a problem with how I have the actuator lever with the spring in the clutch cover installed. Ill take apart the clutch tonight and see whats going on. Hopefully thats the problem then. In 5th it is the worst. It kind of fades off.

duke416ex
06-02-2005, 11:07 AM
If it is a new clutch be sure the springs are tight and just that the cable is right. If it isn't new I would look at replacing it.