Speedster problem - HELP PLEASE!!!!

[Speedster1998]

Here goes... I got a 98 speedster. (Best boat I've ever owned) running fine at the lake the other day. Trailered it to go fill up with gas. (Premium w/ no ethanol) Put it back in the water the next morning. Running great for a few hours. Then rpms started jumping from 4500 to 6000 ever so often on one engine until it started doing it constantly. I could pull the throttle back to 4500 rpms & it would smooth off. Shoot the gas again, & the surging would begin again. Changed the plugs with no change in the surging. went as far as swappin the coils from the non-surging engine with no change in the problem.

I've read many threads & the closest thing that I have found to my problem is dirty rave valves. Has anyone ever experienced something like this??? Any suggestions would be greatly appreciated

 

[Dr Honda]

the RAVE valves don't generally cause a surging that will jump that RPM's that much. But... if you are at 2/3'ds throttle, and they are opening and closing... they can cause a small surge. (a few hundred RPMs)

It can't hurt to check them over, and clean them... but I doubt it's your prob.


To get a drop in RPM that large generally is fuel related. I would look for any leaks in the feed hoses, or a plugged up filter. Then... pull the carbs, and give them a good cleaning. You probably don't need a "Rebuild Kit", unless you find damage.

 

[Speedster1998]

Thanks Dr Honda for your reply. I'm starting to think it is fuel related also. However, I spent about 3 hours on the water today. Same thing. From a dead stop, full throttle, both engines rev to 7k. 4 to 5 seconds in left motor cuts back to 4k & surges from 4k to 5k rpms. Here's the kicker... Put it in reverse, & both motors will hold at 7k with no hesitation or surging. Someone please tell me what the difference is!!! Propulsion is still moving in the same direction & the gate is just deflecting the water that is pushed thru. I would think that if I am having fuel issues then I should be seeing hesitation in forward & reverse. Any suggestions???