White smoke, poor running - Curvy.

Sorry for the bad english, I will do my best!

I have an SV650S from 2000 that only runs on 1.5 cylinders.

When it is turning stationary, only the front cylinder is working, the back one does not want to play along..
Only when I increase the rpms to above 4000 rpm, the back cilinder is working alse..
When I let the engine turn on only the back cylinder (>4000 rpm) there is white smoke coming uit of the exhaust pipe..

I have already done a lot of checking, like:
- fuel suply is ok (vacuum valve and pump)
- carburator completely cleaned/checked
- spark plugs are fine
- ...

I cleaned the carburator and jets with ultrasonic cleaner and checked if all openings where clean and open by pushing some air through them with the compressor..
If I push air through the place where the jets were placed, there is air coming out off all wholes where air should be coming out off..

Is there, besides installing an other carburator, any possibility to confirm/disclude this?

What can I check more?
What else could be a possible cause of this issue?

Thank you for the help!

Hi, how about switching the pilot jets just to check ?

Hi cx5, thx for the reply!!

I already did what you suggested, but the problem stays with the back cilinder.. So that is why I am pretty sure the problem is not with the pilot jets..

Someone suggested it might be the cylinder head gasket..
Can somebody tell me if this is possible?

i would do a compression test to see if the rear cylinder is low on compression

[Sid Squid]

White smoke and poor running could very probably be a coolant leak into the cylinder - obvious suspect head gasket. Are you sure it's only one cylinder that is affected? Watery fuel could just possibly be another cause. It would have to be very badly contaminated fuel, but it can happen.

Originally Posted by Sid Squid

White smoke and poor running could very probably be a coolant leak into the cylinder - obvious suspect head gasket. Are you sure it's only one cylinder that is affected? Watery fuel could just possibly be another cause. It would have to be very badly contaminated fuel, but it can happen.

Yes i am sure about the one cylinder.. When running on only the front cylinder, everithing is normal.. But when only on the bacl cylinder, I have the problem..

Originally Posted by suzukigt380paul

i would do a compression test to see if the rear cylinder is low on compression

We already did this test. It results were that there is enough compression on the back cilinder (it was also equal to the compression on the front cylinder..

Originally Posted by wonderke

Well, I would love to do this, but I do not have all equipment to do this test..
Also if it would be the head cylinder gasket, I would still have to take it to the garage, because for changing that i do not have all necessary tools neither..
But I wanted to be ahead on the problem and sure I tested all other possibilities myself.. At least the ones I have the tools for

beg borrow or steel one or failing that buy a compressin tester,you can normaly pick up a kit for under £30 with all the adaptors

Originally Posted by suzukigt380paul

beg borrow or steel one or failing that buy a compressin tester,you can normaly pick up a kit for under £30 with all the adaptors

Lol.. sorry for the delay in my edit of last post..
It seems that my brother, who is doing all the work btw, did bought this specially to perform the test.. But the test results were as stated above just fine..