Finished my 89 project bike. Got it inspected by CHP and legal, on ride home noticed a whitish blue smoke from front cylinder exhaust while reved at a stop sign.

Thought crap another problem, did a compression check on both cylinder as per manual. getting 115 lbs front cylinder and 110 lbs on rear. Bike motor sat for unknown number of years without even starting. I am thinking it might be valve seal? Anyone got an idea or helpful hint? Spark plugs are still a little black from rich carb setting, have not had it on a ride longer than 50 miles since I got it running but have accumulated well over 150 in short hops and test runs. lastly the smoking issue just started on the last leg of the 50 miles run.

89 sporty stock engine, dyna stage one carb kit, dyna s ignition, stock everything else. 42 slow and 165. I am running synthetic in oil tank 20-50 recommended for HD motors and primarys.

Last question how much air should be coming from the rear crankcase breather? Should I be able to feel air coming out, as I dont really feel anything pushing out, the front breather is the opposite I can hear air from it. I am leaning toward a valve seal issue? any help and suggestions are needed.

 

Sounds like it could be a valve stem seal problem. You have pretty good compression numbers, so it doesn't sound as though oil is getting past the piston rings.

 

I and other metric riders have used a product called AutoRx. It's a slowing working cleanser that seems to work on valve seals and other oil consumption problems. You run it for a 1000 miles with a new filter, then do a complete oil change.
It help stop my start up smoking on a Kawasaki Vulcan 1600.
www.autorx.com

 

I would tend to agree with the OP ...sounds like a seal/guide issue...but first I would check your oil level to make sure it is not too high and check inside the carb where breathers feed to the airbox..might be a bad breather valve causing it to suck oil which by dumb luck is all being draw into the front runner of the intake....Also does it smoke on accel. or decal....if it smokes on accel. it still might be a bad oil ring even though you have decent compression...also you say the plugs are black, are you sure it is from being to rich and not from burning oil??

 

Well I am 99.999% positive it the valve seal. I pulled the carb and intake, used a flashlight and looked in the head. I saw a pool of oil sitting on top of the intake valve. No wonder the damn thing fouled out and did not want to start. Going to try to take a picture of it.

 

here is what I found in front cylinder

 

Okay update: I pulled the head and guess what I am sooooo screwed. The intake valve guide is F'd up so bad it pushed out with the valve after I removed the spring. I found the o rings on the head gaskets were pinched and letting oil in as well. I cant find the broken parts of the intake valve guide , top of my piston has some small nicks in it I have not taken the jug off yet but from what I can see I don't see any marks of nicks in cylinder wall.

So it looks like I am off to local Harley Mech and getting my heads reworked what a drag, at least I did not f the whole engine.

 

sorry to here...what could have caused the guide to come out??? lift too high and valve cap contacting end of guide???that head looks like it just had work done, did you replace the guides??

 

mrfisker,
I did not have the head worked on, this is my first time inside the motor. I bought it as a basket case (Frame and motor) cylinder bore is 3.49 in which sounds like it has been modified to a 1200. The guide looks like is was not put in properly and now the guide hole is out of round, which is why it slide out. I don't know if they make or have over sized valve guides, my valves are good no wear to speak of and the rear head is good.
I am trying to find a good machine shop here in Southern CAli so I can get it fixed and back on the road.

 

that head can be fixed, over size guides are readily available and if the hole is worn too large for even the oversize it can be filled in (welded) and rebored to the proper size...and from the looks of that port in the pic. it looks like the head has been ported...if you can't find a place local you can always mail it to be repaired..there are a couple of good sponsors on the forums that will do the work...