Little Smoke After Rebuild.....????

[Fireman450]

Hi Fellas
just got through with my rebuild on my 05. So far it runs strong, but smokes a little heavy on start up, Its not oil or water I think it might be running too rich, but Im not sure, It has the CRF 450 Carb on it, Id have too look to see what jets are in it because I cant remember off the top of my head... I was just wantin yall input to see if that may be where my smoke is coming from, and it does clear up after about five minuits of runtime when she gets warmed up... Thanks for yall help.

Fireman450

[Jason Hall]

Did you replace the piston with a wiseco?

[Fireman450]

I used the factory piston, It was still in good shape I just re ringed it, I just wonder if maby it could be in my valves, Im going to try and adjust them and see if that clears it up a little.

[Fireman450]

Originally posted by smithn1683
Smoking on start up is an indication of bad valve Guides/Seals. The oil sits in the top of the motor when off leaks through seals down in the valves and piston. It is burned off during start up. Its not crucial to get this fixed but you will start to oil foul your plugs and get build up on the piston. Does it say what color the smoke is? this may also indicate a rich condition on the low end.
Found this with a little deeper searching, I think it answers my question. Thatnk for all who gave input.
Fireman450

[d3ktrix]

Originally posted by Fireman450
Found this with a little deeper searching, I think it answers my question. Thatnk for all who gave input.
Fireman450

What was it?

[Fireman450]

Yea I beleve my valve guides are shot, i dont know why I didnt change them eriler.... so That is the cause of my smoke....

[d3ktrix]

ah ok thanks, that was my first guess :P

[400exrider707]

It could be that or the piston rings. Also smoke on start up is usually oil, not being rich. Rich is black smoke, oil is a blueish smoke. I highly doubt the valve guides are shot already though I wouldn't rule it out, but valve seals are probably a more likely culprit. Also did you offset the gaps on the rings when reinstalling it? What did you do with the cylinder?

[tfuchs]

Valve Guide Seals...not valve guides.

Every time you take your head off it is cheap insurance to replace them to prevent oil burning, You really have to tear your quad up to wear out the valve guides.

[Fireman450]

Alright I got ya, Thanks

[Fireman450]

Originally posted by 400exrider707
It could be that or the piston rings. Also smoke on start up is usually oil, not being rich. Rich is black smoke, oil is a blueish smoke. I highly doubt the valve guides are shot already though I wouldn't rule it out, but valve seals are probably a more likely culprit. Also did you offset the gaps on the rings when reinstalling it? What did you do with the cylinder?

I did off set the rings, and the cylinder was in real good shape...
Right now it is burining a little oil so Im goin to pull the head off....
I did pull my head pipe off and I could see where the oil has leaked past my seals on the valves, so back to the drawin board...
Thanks again to all.

[Rulz]

Did you ball hone the cylinder? Most definitely should do that, then clean your cylinder with warm soapy water, very thoroughly. Wipe down with a white cloth to make sure it's perfectly clean. It's important to get all the minute metal particles from the cross hatch, if you don't your rings won't get "cut" in properly when you first fire up the motor.

Also, when assembling everything back together, do not put any oil on the cylinder or rings or piston, assemble it dry. Just put some oil on the cir clip under the piston. Pull the spark plug, kick it over 50 times hard. Put plug back in, fill with oil and fire it up and ride the crap out of it.

A dry build gives you your best ring seal!