NEED HELP WITH DS650

[darealblaster]

Hey guys, I need help with a Bombardier DS650.

It was kept under garage for about a year. I put new spark plugs, fresh gas and new battery and started it. It started to rev really high and backfire through the carb. I took the carb out and cleaned it throughly. I put it back, but it still rev really high as if it had an air leak. After a while white smoke started coming out the exhaust and through the header which led me to discover the header was rusted out at the Y and apparently has a really really small hole you cant see with the naked eye since its in the middle of the Y.

Can the exhaust leak cause an air leak? Why the sudden white smoke?

 

[Herpderplol]

Being a four stroke, an air leak will not affect the engine the same way.

My guess on the pipe leaking, no. but it will cause it to back fire when you let off (which causes problems later)

a four stroke engine does not need the blow back of the designed two stroke pipe, so its not pulling more air in with the hole.


check the muffler and air box for rodent nests.
Clean air filter

 

[Blaaster]

Is that white smoke really smoke or could it be steam.

If there is a fluid leak into the combustion chamber it could cause a higher than normal idle and give the impression of white smoke.

An air leak can cause uncontrollable revving as in a two stroke due to a lean mixture, but not tithe same extent.

 

[darealblaster]

The air filter has been cleaned and the muffler does not have rodents. I'm so confused right now, I've tried everything and cant pinpoint what is causing the high rev.

 

[Blaaster]

High revs lead me to believe a lean idle.

How dirty was the carb, was there any dry whitish deposits in it, if so did you make sure that all the internal passages were clean, by blowing through them.

Does it still white smoke because it could have been caused by condensation.

What steps have you done to correct the idle problem?

 

[darealblaster]

High revs lead me to believe a lean idle.

How dirty was the carb, was there any dry whitish deposits in it, if so did you make sure that all the internal passages were clean, by blowing through them.

Does it still white smoke because it could have been caused by condensation.

What steps have you done to correct the idle problem?

When I cleaned the carb, I made sure to clean all passages with carb cleaner and make sure they were not clogged up. The float needle was stuck and had aloot of black gum build up, but that was BEFORE I started the ds650. To correct the idle issue ive been messing with the air screw AND idle screw.

The white smoke started after a few starts, and now it just immediatly starts coming out after starting the ds650. Which did not happen at first. Maybe the lean condition caused some damage on the valve seats and its leaking oil?

Also it finally could have worned out the piston rings? Mind you this engines has NEVER been opened, let alone rebuilt. It has low hours although it has its 13 years since manufactured.

 

[darealblaster]

Ok, so i got it working...turns out its in the detail. First, the white smoke appeared to be steam. And second, the problem was that somehow the idle screw was stuck, and while the screw turned, the cable did not. So i got that working and settled the idle and its running great.

Thank you all for the help!

 

[Blaaster]

. After a while white smoke started coming out the exhaust ?

This is what led me to think that is was steam caused by condensation.

Glad that you have fixed the problem.