SX/SXi/SXi Pro Bad engine bogging after right hand power slide

[clayne100]

I just got my 95 750 SXI back together from winter rebuilding the hull, No engine or carb changes. I took it out for the first time and found I have a really bad engine bog when I power slide the ski. The bog is worse to the right than the left and also when the ski rolls to the right side. At it's worst, the ski was smoking and would barley start. Eventually it would clean up and run fine, that is until I put it into another power slide. My guess is that somehow I am dumping extra fuel into the engine during this process. The question is how do I fix it? And fast, I have a big trip with the ski in 7 days.

Engine is stock except factory dry pipe with ECWI and Tau Ceti filters. Thanks in advance for the advice.

Courtney

 

[clayne100]

Crickets! Someone has to have seen this before. Or at least an idea to try. Anyone?

 

[LMnsr]

I have a similar problem with mine. but when doing 180's in the air.
When I land backwards 2 out of 5 times it bogs the engine and i have to kind of drag myself idling playing with the throttle until it frees up.
My guess is the exhaust and waterbox filling up with water causing it to bog until the water is pushed back out. Kind of like putting your hand over the exhaust.
I am running a factory b-pipe with true dual cooling but without a flow control valve for now (planning on ordering one). So my pipe and waterbox keep filling up at low rpms making the engine have to push the water out. instead of keeping it dry and getting a quicker response.

 

[shadowrider]

My guess is you are ingesting water. What changed? Did you remove the carbs, intake, ect.....bad gasket not sealing? Did you just put on the Tau Ceti filters? I would guess you are sucking water in, just have to figure out where?

 

[Captain PegLeg]

I had the same think happen to my kawi 750 years ago.... I didn't change anything besides take off the factory flame arrestor and install two open f/as. Strange part was, it ran fine for a few weeks then developed this same bog. Swapped out back to the OEM f/a and never looked back.

 

[crazy4sand]

Put your stock flame arresters on, could be a leaky hood seal aswell...

 

[clayne100]

I have thought about water up the exhaust but it doesn't seem like a good fit. Riding it, I was not really in a situation to force water up the exhaust pipe. I have experienced this in the past with the ski but it took a lot more effort like a faster slide to 180, and it would not bog down as bad. And then it seemed to recover more quickly. But it is worth investigating. I think I can rig up the stock flap again to see if it helps mitigate this.

Nothing and everything has changed on the ski. The ski went thru complete hull reconditioning this winter (crack repair, reinforcing, paint, turf, etc) but the motor/carbs never came apart. If the ski ran crappy elsewhere, I would suspect that I had an assembly problem but it is running good.

Interesting about the open F/As. I have had this same motor setup for 10+ years (stock F/A is long gone) but seems like the last couple of summers, tuning has been getting harder. I figured it was the stock carbs getting older, especially since they are a pain to tune in the first place. I have a set of stock SXR Mikuni carbs that I was planning on installing after I confirmed my rebuild didn't mess anything up. Sounds like they are worth trying, especially since I only have the stock F/A for them.

 

[Quinc]

I had this same problem a couple weeks ago but when i jumped up out of the water. Ended up being my tank breather valve line was pinched in the hood. Once i took the hood off and the gas tank filled up with air the problem went away.