Randyrandy
New Member
So:
This has been discussed ad nauseam here but I can not figure mine out. I suspect that you all are tired of this discussion, but I have been working on this for a very long time with no success.
The Problem: Revs fine on the trailer. Will only go maybe 5 MPH in the water. When first started it jumps up on plane, then very quickly (3-4 seconds?) slows to estimated 5 mph. It will idle all day and putt around all day. I guesstimate that the revs are maybe 3000 or less.
When the problem occurred, (reported to me, I have never been able to get it to run properly) it apparently happened suddenly while riding.
What I have checked:
1. swapped carbs with known good - traded with my other ski. The other ski runs like a scared cat with the carbs from the machine that will not run properly.
2. replaced fuel lines and cleaned filters in the carb and in the line - no change
3. bypassed the fuel selector, pulling fuel from the reserve connection to the tank. no change
4. unplugged the voltage regulator - no change, then replaced with known good - no change.
5. rebuilt top end. compression 150 both cylinders
6. Rave valves rebuilt, also swapped with known good
7. wear ring not excessively worn (if this was the problem it would rev too high)
8. Inspected the rotary valve. looks new. bad rotary valve usually makes hard starting as well. This one starts right up. did not check timing because it initially revs when first in the water, then it doesn't. If a bad rotory valve timing it would never rev.
9. inspected pulse line. no apparent cracks or leaks. a leaking pulse line would cause the machine to run lean. Pulling the choke kills the engine immediately which could indicate it is running rich, but certainly not lean.
10. drew a sample of the fuel. No water, no discoloration.
11. plenty of oil
Current known or possible suspect items:
1. speed sensor wheel is missing, shaft is there.
Q is there an over speed limiter?
2. mpem, ignition module, other?
What think you? what do I do next? I am thinking to swap ignition modules, however it is not clear where the rev limiter resides (ignition module or mpem).
One of the things that is really bothersome about these forums is that very rarely does someone who started a thread indicate what fixed the problem. It is just left hanging.
This has been discussed ad nauseam here but I can not figure mine out. I suspect that you all are tired of this discussion, but I have been working on this for a very long time with no success.
The Problem: Revs fine on the trailer. Will only go maybe 5 MPH in the water. When first started it jumps up on plane, then very quickly (3-4 seconds?) slows to estimated 5 mph. It will idle all day and putt around all day. I guesstimate that the revs are maybe 3000 or less.
When the problem occurred, (reported to me, I have never been able to get it to run properly) it apparently happened suddenly while riding.
What I have checked:
1. swapped carbs with known good - traded with my other ski. The other ski runs like a scared cat with the carbs from the machine that will not run properly.
2. replaced fuel lines and cleaned filters in the carb and in the line - no change
3. bypassed the fuel selector, pulling fuel from the reserve connection to the tank. no change
4. unplugged the voltage regulator - no change, then replaced with known good - no change.
5. rebuilt top end. compression 150 both cylinders
6. Rave valves rebuilt, also swapped with known good
7. wear ring not excessively worn (if this was the problem it would rev too high)
8. Inspected the rotary valve. looks new. bad rotary valve usually makes hard starting as well. This one starts right up. did not check timing because it initially revs when first in the water, then it doesn't. If a bad rotory valve timing it would never rev.
9. inspected pulse line. no apparent cracks or leaks. a leaking pulse line would cause the machine to run lean. Pulling the choke kills the engine immediately which could indicate it is running rich, but certainly not lean.
10. drew a sample of the fuel. No water, no discoloration.
11. plenty of oil
Current known or possible suspect items:
1. speed sensor wheel is missing, shaft is there.
Q is there an over speed limiter?
2. mpem, ignition module, other?
What think you? what do I do next? I am thinking to swap ignition modules, however it is not clear where the rev limiter resides (ignition module or mpem).
One of the things that is really bothersome about these forums is that very rarely does someone who started a thread indicate what fixed the problem. It is just left hanging.
