95 seadoo speedster speed limit problem

[Bigmantony]

I have a problem with one of my engine. One seem to stop @ 6000 RPM. The other go up to 7000 RPM. I know it might be a MEM problem that could cause this. The speed limit in forward or reverse is 7000 RPM and 3500 RPM in neutral. I can test this by disconnecting the tach wire to the MEM. I like to know if there is another reason or reasons for this. Note the engine has good compression and starts and runs fine. No fouling plugs ands runs fine for hours. Also can someone explain how the speed limiter circuit works. (how those it cut the spark/power to the plugs)

 

[Waterluvr]

What are the compression numbers on that engine? Check your throttle cable adjustment, I find cables quite often that won't pull the throttle butterflies all the way open or a dual linkage bar that's not set up properly. When was the last time the carbs were serviced? Weak fuel pump, clogged filters and obstructions in the jet circuits will cause that in a real hurry leaning out your motor and taking it to an early grave.

Providing you don't have more than a 10% loss of compression and your ignition is firing properly you'll likely find your problem on the fuel side of things, I always check and rule out compression and ignition issues first as they only take a couple minutes to verify before moving on to the many variables of the fuel side.

 

[Bigmantony]

Compression good 155 PSI on both cylinders. have a spare carb change it no different. Fuel filters blown out and clean. All cables tested and adjusted. Thanks for your comments.

 

[Waterluvr]

I would look further at the fuel system supplying that motor. A bad fuel line and or impulse line on the pump, loose clamp or o-ring on a separator filter will drop your fuel pressure and can cause that. I'd vacuum test across any filters and all lines, replace the selector valve and swap fuel pumps.

 

[Mekanix]

On that engine what happens if you throttle up from 3/4 to full throttle ? does it reach its peak at 3/4 and seem to bogg when you go past that ? If so I'd say fuel related. This is what mine was doing when the fuel seperator Oring was cracked and leaking.

 

[Bigmantony]

where is that located. I have a manual

 

[Bigmantony]

never see or smell any fuel.

 

[Mekanix]

Its the water/fuel separator. Follow the fuel line from the carb ro the tank. I'm not completely sure your model has it. It might just have fuel filters instead.