hey guys , i ve got a brand new gm marine 502/502hp in my 24 ft. CONDOR (ARONOW DESIGN V HULL ) I'M GETTING ALOT OF VIBRATION FROM 1000-2000 RPM,shakes the whole boat like a drag car! is this normal?it does it standing still or coming off plane.i'm running lightning exhaust with a 26 labbed bravo 1, so far ive seen 5000rpm max at 69 mph (gps) does this seem ok? i didnt know if i should go back to a 3 blade mirage, the boat is rocket out of the gate,it will pop out of the water if i gas it too hard. let me hear some feedback--thanks guys!

Did you reuse your old flywheel? If so it may be the wrong one. The 454's and 502's with forged pistons and crankshafts use a flywheel and balancer with a different balance than the motors with cast components. The modern BBC is externally balanced and these parts must be correct for the application. You can get a GM Performance catalog from a Chevy dealer with a decent parts dept. In the book it tells you which flywheels and balancers to use with each engine.

Good luck,

Ron

thanks ron! this 502 came with a flywheel,but it was for an inboard set up and the ring gear was on the rear side . of course,i found this out the hard way when i went to start the motor and the starter didn't engage! pulled the motor back out and swapped it with a flywheel off a 454. (330hp) anywon have the part # i need ? 502/502-bravo 1 thanks!

try this part#10185035
it is 14" diameter w/168 teeth
i work at a dealer
if you want gimmie a call
877-942-3267 ext149
you're on OSO so i'll hook you up

Russ

sorry typo on the p#
should be 10185034

should have a step cut in it for the ring gear on both sides bring it to a clutch shop and they can swap it to the front