Rotary valve need adjusting?

[GTX rider]

I put a new motor in my 97 Seadoo GTX in October and it idles rough. It runs like a scalded dog once you get on it but at idle and low speed it doesn’t seem to run smooth.

The carbs were overhauled about a year ago. I check the adjustments last night and they are within spec.

Could the rotary valve be out of adjustment? I installed it based on what the instructions gave me when putting the new engine in but the dial was a little confusing. If the plate was off on notch would this cause the ski to run rough at low rpm's?

 

[custompartsguy]

I put a new motor in my 97 Seadoo GTX in October and it idles rough. It runs like a scalded dog once you get on it but at idle and low speed it doesn’t seem to run smooth.

The carbs were overhauled about a year ago. I check the adjustments last night and they are within spec.

Could the rotary valve be out of adjustment? I installed it based on what the instructions gave me when putting the new engine in but the dial was a little confusing. If the plate was off on notch would this cause the ski to run rough at low rpm's?

I do not know enough about the rotary valves to answer your question but, has it been giving you this problem ever since the new engine was installed, or did the problem just arise?

 

[GTX rider]

Its been since the new engine.

 

[custompartsguy]

was it like that with the old motor? Check for a vac/air leak as well. Spray some wd-40 or carb cleaner around the base of the carbs/intake manafold and see if the rpms change while spraying them.

 

[timmyboy76]

if you were off a "notch", it would show up, based on your markings on the case, when you installed the valve.

Howd you go about "marking" the case for your alignment?

 

[MIGUEL CARBAJAL]

I did the same thing, I removed the rotary valve plate to remove my carburators on my 96 gtx 787 and accidently pulled out the rotary valve...just to confirm, you need a degree wheel to figure out where the valve shoud be at...I've been reading about this and I know if Im off by one notch the ski wont run right so im trying to figure it out...I'm kinda lost, is this a do it a home kinda of thing or should i just take it to a seadoo mechanic?

 

[timmyboy76]

at home, stud...bring mag piston to TDC, then mark ur casing, from center of gear, drawing a line, pass the top of mag hole, to the edge, then the same, but bottom of hole, to outer edge. The bottom marking is then used to go 147*, counterclockwise, the top marking 65* clockwise. Then align your RV to the 147*/65*...

 

[MIGUEL CARBAJAL]

thanks Timmy...I guess I got tired of messing with it so I just took it to my local mechanic he said he would do it for a couple bucks...now i just got to put everything back together...hopefully I get it right...

 

[MIGUEL CARBAJAL]

Hey timmy, just wondering, how would I manually get the piston to TDC...?

 

[96xp800]

Hey timmy, just wondering, how would I manually get the piston to TDC...?

You can insert a dial gauge into the magneto cylinder and turn it manually by rotating the pto fly wheel, it's under the gray cover.

 

[MIGUEL CARBAJAL]

ok...had a local mechanic set my rotary valve (charged me $40)...I cleaned out my carbs the best i could without rebuiding them...all the diaphrams looked good, no tears...bought new gaskets and a few new bolts...but I got stumped with the gaskets...I know it needs two gaskets in between the rotary valve plate and the carbs and I swore it also needs two more between the carbs and the housing arrestor...!I know, I know! I guess i wasn't paying attention when I took them apart and i apparently lost the old gaskets (If it had any)..Im looking in my manuel and it doesn't show any gasket in between the the carbs and arrestor but thats got to be wrong?????......or not

 

[lilngineer]

Please tell me you found a solution?

I have almost 100 hrs into diagnosing the exact same problem on my 787. I am ready to split the case.

Please help!

 

[timmyboy76]

most settings for 717/787 are 147*/65*