New top end... cant figure out whats the problem...white smoke

[Slickgib]

1987 banshee. stock. just had my top end re done by a machine shop, put everything back to gether... now the thing boggs way down then shuts off and puffs a crap load of white smoke. i took my cool head off again and checked to see if i was pinching an o ring. but all that was good.. on the gaskets for the heads should i have put sealer on them? do u think coolent is leaking into the cylinders? please help me out.

[grandnational]

1987 banshee. stock. just had my top end re done by a machine shop, put everything back to gether... now the thing boggs way down then shuts off and puffs a crap load of white smoke. i took my cool head off again and checked to see if i was pinching an o ring. but all that was good.. on the gaskets for the heads should i have put sealer on them? do u think coolent is leaking into the cylinders? please help me out.

 

check ur fluid in the radiator after a ride..

[dajogejr]

Did you put the rubber plugs back in the bottom of the cylinders? Unless those are bad, it's only going to leak coolant into the cylinders from the top (barring and cracks in the cylinders/water jackets internally, of course).

 

You probably have a dip or uneven spot on top of the cylinder or the bottom shell of the head.

before I assemble a motor, I take a medium grit wet sand paper on a sanding block and remove the head studs.

 

I go in a figure 8 5-10 times and then look at the deck surface (top of the cylinder) if I can see a scratching all the way around, I'm good. If I see an area that is not being scratched, I sand lightly till I do.

 

I take the domes out of the head and do the same thing with the bottom shell of the head.

 

if either of those surfaces are not flat, you're fighting a losing battle. Usually it won't break an oring unless you've got it pretty warmed up and a load and RPMs to it.

 

Just warming it up or idling in the garage won't break an oring unless the head/deck surface is WAY out of whack.

 

I built a cub motor 4 years ago that had a dip in the center of the cylinders and a base gasket leak.

Some times...you just learn the hard way....LOL.

[BigRed350x]

What do your spark plugs look like?

 

You asked if you should use some sealer on the gaskets for the head... are you using the head gasket along with the cool head o-rings? Don't do that if you are. The cool heads are designed to run with just the o-rings. No need for a head gasket if you have a cool head.

[Slickgib]

i took it all apart again and put everythingback together super slow. i did have to use some sealer on the botton of the left cylinder i did notice a leak. anyway. after doing that it runs super good. lots of power. my other queston is. my right pipe smokes a bit more then my left

[flyhighprerunner]

i took it all apart again and put everything back together super slow.

sweet, thats the best way!

 

i did have to use some sealer on the botton of the left cylinder i did notice a leak.

what was leaking

 

anyway. after doing that it runs super good. lots of power. my other queston is. my right pipe smokes a bit more then my left

so maybe the problem isnt totally fixed?

[Slickgib]

My bike has always puffed more smoke out the left pipe then the right. Weird. I just pulled my new plugs I had in there and the left side was chocolate brown the right was a bit lighter? Should I worry?