No the dyno is set up with it's own box...I made it 's last pull about 3 weeks ago...

im wondering if the timing is diffrent now that you tuned it all in with a diffrent ignition? the msd ignition might have it just alittle bit off??

i had an issue a few years back...
somehow between msd boxes or some "help" from a mechanic, the two wires that go to the distributer reluctor (i think that what its called...???) were backwards. boat would idle, but missed and backfired horribly when given some gas,,,basically the timing was all over the place...finally swapped the wires and issue resolved...

good luck

Usually if ya have two different boxes the timing will be slightly off, as soon as i fired it in the boat i put my timing light on it..

Check if the two wires to the distributor is in contact with the wire from the coil to the distributor and the spark plug wires.

It happened to me once when I changed the ignition in another boat and it lost power and about 1000rpms.

It might have something to do with it - you never know...

youre right. its just better if the problems aren't self inflicted . but never the less , i apologize for cluttering up this diagnostic exercise.

Touchee, now if ya have a lot of expierence with blown up msd's unload i am listening....

which dist are you running ? msd pro billet ? sounds like the magnetic pick-up went, had it happen end of last season on my top sportsman car, would run, barely, more i checked thigs the worse it got, sent all the stuff back to msd they checked it all out, found the bad pick-up, also how is you coil mounted ? needs to be strait up....mounting then sideways makes them overheat and fail, Rob

That is what is weird, it will run almost unnoticed until you bring it on plane , then it stumbles and misses.....Real inonsistant..It is real hard to tell at a idle with dry pipes and a huge cam...

Back to basics.
Check simple things.

Grounds
Check big red wire for atleast 12 volts with DVM.
Check the trigger wire for the same.
Check polarity of coil.
Check polarity of the Distributer.

Check the distibuter cap (inside) for tracing.


Your sure on ignition problem? Fuel pressure gauge?