Smokin'/Tranny clunk

[ontario400ex]

my '00 400ex smokes. Blue. Not at idle, not after startup. Above half throttle when it's under load, and under decelleration. Cold compression checks ok, hot compression checks ok. No loss of power at all, just foggin' my buddies....

Valve seals?

Has stock high speed jet, and a #45 pilot. Rest of the bike is Stock.


Also, I get a nasty clunk when I shift from neutral into first. Shy of me pulling the side cover off to look at the clutch basket, has anyone else had this problem? Has a new Honda clutch cable on it, and it's properly adjusted.

I've done a search on both of these things and I can't seem to find anyone who has had the same symptoms as me.

Lemme know.... Sound like the engine's coming out this month to get an expensive rebuild.

-Scotty

[ontario400ex]

Something else I thought about that might help...

With the engine off, transmission in gear, I can roll the quad fore/aft about 8"....

-Scotty

[Bill Fuller]

Sounds like someone needs a transmission rebuild. I would bet that your gears are chewed up,this is common on the 400EX. When I replaced mine it was 2nd and 5th I believe.As far as the smoking sounds like valve seals or rings.

[rooster300ex]

Sounds like its just wore out. when my quad is in gear i can roll it quite a bit too. Do you change the oil very often. It could be the valve seals, but I don't think valve seals make a quad smoke underload and giving er hell. I bet your clutch is wore out too.

[Old Head]

Originally posted by Bill Fuller
Sounds like someone needs a transmission rebuild. I would bet that your gears are chewed up,this is common on the 400EX. When I replaced mine it was 2nd and 5th I believe.As far as the smoking sounds like valve seals or rings.

If this is a common problem why is there not a ton of posts about it? Just wondering since I have an 00 and 02 with no problems.

[ontario400ex]

I adjusted the chain and it took alot of the slop out, it really only rolls about 4 inches now.

The tranny problem is fairly common, do a search on it... I found tons of posts.

She's getting a top end rebuild.... sometime.

What would you recommend? I'm trying to keep her as reliable as possible. I don't care about gobs of power or a hundred thousand miles per hour...

406?
416 and a stage 1 cam?

-Scott

[oldskoolex400]

416 11:1 with a stage 2 cam and a hd cam chain