'93 XP won't exeed 4k RPM!!

[Cutlass84]

What I've done so far..

-Cleaned carbs, pump, selector valve, and replaced fuel lines

-fresh top end

-disconnected the red wire from rectifier, also checked running voltage

That said.. It sounds great running in or out of the water.. If you try to give it some throttle it revs smoothly up to about 4k then refuses to go further. It sounds like spark is cutting out to me. I suspect the cdi/MPEM but can't find a procedure to ohm it out or otherwise test it before throwing another on.

I have had the rotary valve off, but am fairly confident I reset it correctly. Am I missing anything? Suggestions?? It runs and sounds so sweet until you try to rev it past 4000! I'm running out of ideas!

 

[Dr Honda]

Well... a '94 xp doesn't have a low RPM mode... so if it sounds like it's hitting a rev-limiter... then you have an issue with the MPEM, CDI, or coils.

But... you could have a bunch of metal filings stuck in the MAG, and it's messing up the signal.

For this one, you will have to methodically check each part of the ignition, and if nothing shows up... then the MPEM will be suspect.

 

[Cutlass84]

I pulled the front cover and don't see anything suspect, as far as no metal shavings, although you can't see the magneto without pulling the flywheel.. It shows right at 14 volts just off idle.

Will this model not even rev limit when overheating? (I did try running with overheat sensor disconnected, with no change)

Everything in my box looks pristine.. It would seem a coil would be marginal at all RPMs, or no? I'm about to try a MPEM and see where that gets me I think..

 

[Dr Honda]

Yes... on a 94, there is no "Limp" mode. So... you can run full throttle on an overheat condition. Well... at least until the piston sticks.

You have to remove the flywheel to look at the mag... and the charging coils have nothing to do with the ignition coils.