3 cylinder yamaha 90hp

[bad news racing]

Cannot get the thing to turn over 6750 RPM.
Every thing we try throws us back to around 4500,
starting to not like this motor!
any suggestions. Thank in advance
1992 model :confused:

[zul8tr]

Are you saying that when the engine is pushed over 6750 it falls back to about 4500?
Is there a rev limiter?
List what have you tried?

[bad news racing]

the most we can get is 6750 .
if you try to advance the timming it goes in to some kind of safe mode then will only turn4500. Put it back where it was , back to 6750.
I think it is in the pack , but i don't know how it works inside.it has that arm with that pointer on it. Changing jet size up and down does not help?:confused:

[zul8tr]

Sounds like you have a rev limiter in the computer pack. I am familiar with car computers and how to change the rev limiter but not familiar with the outboard computer. Hopefully sombody will chime in who knows.
Have you tried a Yamaha web site for a how to?

[bad news racing]

the rev limiter is cut but ,the problem is still there . We have run down an old style ,just going to swap it out make it work , The race in Moss Point is in less than a month.

[MHARDEE]

the most we can get is 6750 .
if you try to advance the timming it goes in to some kind of safe mode then will only turn4500. Put it back where it was , back to 6750.
I think it is in the pack , but i don't know how it works inside.it has that arm with that pointer on it. Changing jet size up and down does not help?:confused: IF THE TIMING POINTER GOES PAST IT RANGE IT WILL FALL OFF -------IF YOU CAN'T GET 25 DEGREES WITH POINTER by the time it gets to THE FULL ADVANCE NOTCH ----SLOT THE HOLES ON TIMERBASE AND ADVANCE THE TIMERBASE (witch will need to be rotated counterclockwise slot mounting holes usually about 5/16 in ) THE EXTRA FEW DEGRESS U NEED TO GET TO 25 . if need call me and i an explain it better on the phone 803-974-0350 HOPE THIS HELPS Mitch

[bad news racing]

Thank Mitch , The old style adapted on pretty easy , ran right up to 7150 and pulled the wrist pin out the piston :( just about got it back together with a different block, any idea where to get good pistons?


ps: might swap this box for a piston r 3