White smoke comes at a steady rate after each pop while holding a steady high RPM in with no load. It also comes when revs drop from revving up. Slight smoke coming out of the right side head connection to the pipe. I also noticed that the right exhaust is cooler then the left side exhaust, gas wise. Just tested compression and I am at 147, 153 left and right. Plugs are both a black, mixture screw is set 2.25, runing pod filters. Pamco ignition, HHB PMA, mechanical timing, straight pipes with a small diameter. Valves have been set to spec via clymers manual. 78' XS 650F
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White smoke and popping right side. Help
- Thread starter jchen
- Start date
xskid
xskid
Sounds like head gasket or valve seals. Either way sounds like your burning oil. P.S. that really sucks man.
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xskid
xskid
Has it been sitting for a while? Is it a fresh rebuild? Typically it well lower compression. Oh have you checked your float height?
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xskid
xskid
I had a blown head gasket on my 318, it made 140 -145 all the way around before I tore it down. So actually I don't know if it will lower compression
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its been sitting for quit a while but i had that problem before i let it sit.
Your compression is ok. The book calls for 145 minimum on a good engine. Yours does vary a bit side to side, about 4%, more than 10% might be something to worry about.
If it's white smoke, does it go away after warming up?
Black plugs, wet and oily feeling or dry and kinda fluffy? Wet and oily is to much oil, Dry fluffy is too much fuel.
Have you read the carb guide? It has a tuning section in it. It could be the way the carbs are tuned.
Leo
If it's white smoke, does it go away after warming up?
Black plugs, wet and oily feeling or dry and kinda fluffy? Wet and oily is to much oil, Dry fluffy is too much fuel.
Have you read the carb guide? It has a tuning section in it. It could be the way the carbs are tuned.
Leo
It gets worse as the engine warms up, under a constant no load rev the smoke spits out at what seams like ever other stroke. Plugs are hard packed black with a slight bit of fuel. I tuned my carbs up to spec all except for the sync but i just noticed a bad vacuum barb cap on the left side but the right side is running bad which confuses me 
sync was tuned roughly by feel. Compression was not accurate could be more as i measured it via kick and i checked it after my foot got tired.
sync was tuned roughly by feel. Compression was not accurate could be more as i measured it via kick and i checked it after my foot got tired. crashcourse
XS650 Addict
If you've added pod filters then tuning the carbs to what the book says may not be right for your bike. Not saying that's your problem, just FYI.
Check your oil for gas. If you're leaking gas into the engine it will cause white smoke, but usually on both cylinders.
Check your oil for gas. If you're leaking gas into the engine it will cause white smoke, but usually on both cylinders.
New update. Had a 1 wire lose on my wiring harness for my rect/reg and was causing charging issues so I figuring that out 1 connector that was attached to the male harness was out of place. 
took for ever to find.
Just replaced new spark plug caps to stock equivalent NGK ones to run the BP7ES no resistors. Got new vacuum barb covers to replace my old cracked barb caps. Fired her up and it was running a bit smoother. Still popping/misfires on right side with smoke, but under hard acceleration smoke turns black. I noticed a black fluid coming out of the pipe and a little bit out of my header connection. It was some sort of wet carbonized liquid. No inherent smell of gas not very viscus or oily. It just smelled burnt like exhaust. I have no idea what that is.
took for ever to find.Just replaced new spark plug caps to stock equivalent NGK ones to run the BP7ES no resistors. Got new vacuum barb covers to replace my old cracked barb caps. Fired her up and it was running a bit smoother. Still popping/misfires on right side with smoke, but under hard acceleration smoke turns black. I noticed a black fluid coming out of the pipe and a little bit out of my header connection. It was some sort of wet carbonized liquid. No inherent smell of gas not very viscus or oily. It just smelled burnt like exhaust. I have no idea what that is.
As an engine burns fuel it creates water. This water will mix with the carbon in the chamber and exhaust. This might be your black fluid.
Have you read the carb guide? It has a tuning section in it.
Leo
Have you read the carb guide? It has a tuning section in it.
Leo
angus67
Welder's penetrate deeper!!
condensation?
What brass are you running in your carbs? You say you put them to spec. That would assume stock pilots/mains? Sounds like your running way rich on pilots, and way lean on mains, with bad valve seals. Does it smoke on deceleration?
And you really should use a manometer to sync your carbs. its real easy to make. made my first one in 15 minutes, and since your carbs are already close, it should take less than that to sync them. that middle screw between the carbs only adjusts the right carb. in essence, it adjusts the right carb idle to be the same as the left carb.
As for smoke coming out the front of the head pipe, just a exhaust gasket should be all you need there.
What brass are you running in your carbs? You say you put them to spec. That would assume stock pilots/mains? Sounds like your running way rich on pilots, and way lean on mains, with bad valve seals. Does it smoke on deceleration?
And you really should use a manometer to sync your carbs. its real easy to make. made my first one in 15 minutes, and since your carbs are already close, it should take less than that to sync them. that middle screw between the carbs only adjusts the right carb. in essence, it adjusts the right carb idle to be the same as the left carb.
As for smoke coming out the front of the head pipe, just a exhaust gasket should be all you need there.
Very likely the head gasket is passing oil into the combustion chambers.
I'm guessing that engine has had a hard life, rode hard and put away wet. Probably has lots of miles/kms on it.
Normal compression readings mean nothing. As the carbon builds up on the head and the piston tops, it actually increases compression.
My suggestion......................top end re-build for a tired engine.
I'm guessing that engine has had a hard life, rode hard and put away wet. Probably has lots of miles/kms on it.
Normal compression readings mean nothing. As the carbon builds up on the head and the piston tops, it actually increases compression.
My suggestion......................top end re-build for a tired engine.
I had my float hight put to spec as specified by clymers manual, i dont know what pilot or main jet im running but Im guessing it might be different on the both sides considering the issues. My left side runs perfectly no problems at all. Under hard acceleration, no load, i do get a bit of backfire with a jet of fire i guess that means im running rich? when im engine is under load it seams to do a bit better but at this moment my options for a rebuild are limited due to budget and time.
I will respec my valves on the right side maybe that is an issue with the valves opening too long or short. I will also get an oil change as mine is super dirty probally washing out all the old built up sludge and carbon.
I will respec my valves on the right side maybe that is an issue with the valves opening too long or short. I will also get an oil change as mine is super dirty probally washing out all the old built up sludge and carbon.
