MY XJ750 Gokart Smokes out exhaust!!!

can anyone help i think it might be the rings but it shows good compression, so it could be the valves or something else thanks.

 

Could be valve stem seals if it's not the rings.
Could need a good run if you haven't been running it.
What's "good compression??"

 

HERE IS A VIDEO

http://www.youtube.com/watch?v=t9hZBUGvFMc

 

#1 IS 125 #2 110 #3 125 # 110

 

Yeah- - you're running on 2 CYL until you get on it, then maybe 4.
Spray water on the 4 header pipes to tell which are working better for you.
The pipes that stay wet have carb problems in the Pilot, or idle circuit.

Your coils look like they are not grounded- - I know they will work ungrounded, but maybe a detail??

Have you checked your oil for gasoline??

There could be many problems, I'm just trying to help- - anyone else??

 

I think it is pi@#ed off because it wants to be on 2 wheels :lol:

 

ya well the two wheels it was on were flat

 

So this is like a wheel chair for the ol' girl

 

it just started smoking since i stopped a valve cover leak, + when i just took the spark plugs out they had oil

 

shit that must be a crazy ass girl

 

whats the compression supposed to be at

 

I get 147's with all plugs out and battery on a boost, throttles open.

That sure looks like a fun go-kart, but there's one problem with the design- - no airflow to cool the motor. You're running hard in low gears and making alot of heat off road, where a bike is barely on the gas at, say 40 MPH. Too much heat and you "cook" the rings. They lose their tension and compression goes away.

Add a fan ! Quick !

 

ya im going to make a fin on the side to direct airflow. i took one plug at a time out would that make a deference. i think it might be the valves cause she start good its just when it pressurize it starts to smoke. i aint worried though i aint got no money to buy rings or valves

 

Not sure about the main problem, but perhaps a universal electric fan for a car would be in order to keep down the heat? Just sayin'.

 

i took off the exhaust and turned it over and it make a hiss sound out # 2 and #4 has got oil all in it so i think it might be valve seals

 

it turned out i had 6 quarts of oil in it, when i got it i though it was empty so i put 4 quarts and that's why it was burning oil , but know i cant get it to idle it revs up then back down and dies unless i hit gas or choke then it revs up high again , it like has a long rev

 

... do you have an airbox or an anything?, maybe for giggles, if you have the original airbox and filter and slap it on there see what happens..

maybe you should try cleaning the carbs, be sure to clean the emulsion tubes, and polish the bores so your slides pass the clunk test, also a bench sync should help..

 

yes i have a air box but the engine is not on a bike its on a go kart and it wont fit, is it possible that's the problem , and what is a bench sync and clunk test

 

Valve SEALS will not cause a compression leak. They just keep oil from running down the stems into the piston.

If you are hearing a hiss sound, the valve are not closing completely or have a burnt SEAT (metal mating surface to valve)
Have you check the clearances (they first place to check)
If they don't have any clearance they aren't allowed to close completely and will leak eventually burning the faces.

If the seals are leaking, you'll see the oil residue on the valve stems when you look in the intake/exhaust ports.

Valve seals are pretty cheap (like $5 each)
head gasket not so cheap

 

clunk test is where you take the top off the carbs, take the spring out, leaving the diaphram and slide, then lift up on the slide from the bottm, and let it drop, should fall like a rock, and hear a cling sound...

bench synching- i used a 1 cm strip of cut up pop bottle, then you use the idle screw for the # 3 carb so that is just tightens down o nthe strip where you cannot move it, then adjust the number 4 carb to the same specs, then adjust the number two to the same specs then number one to the same specs..
then you vac sync the carbs, color tune the mixture settings and so on, this motor is going to be more difficult to work with than a briggs..

 

so wat happens if i dont do most of the tuning since the tools are expensive will it mess up stuff

 

no- a good bench sync will work since you're using it on a go cart- since you dont have the original airbox, i can imagine you're running lean... if you can drive it around, do so for a little while, and have the bike at highish revs and then hit the kill switch and pull the plugs, should look like coffee with alot of creamer

a good carb cleaning costs- a little bit of 1000 grit sand paper and some wd 40 to sand the bores, i like to use qtips in a drill with some brasso to polish the seats, and then a can of wall mart carb clean to clean out holes... and dont forget those emulsion tubes!!!!! those are probably a good bet that may be your problem, if you look through your carbs, they're the brass thing that your needle touches and a jet screws into it, make sure every hole in that sucker is clean... because in that video you posted up your motor isnt running right... your carbs need a good cleaning

 

ok thanks ill post a video tomorrow after i clean everything. thanks again