rssteiny

BOAT IS A 1994 SONIC W/ 502 MAGS W/ THUNDERBOLT IGNITION IV. ONE MOTOR ALWAYS SPINS 4900 THE OTHER ONLY 44OO. SO PUT PLUGS IN THE LOW R MOTOR AND FOUND THE TIMING OF 16% IT WAS AT 8% ATC SO SET IT AT 8% BTC THE MOTOR CAME TO LIFE WE PUT IT IN THE WATER TODAY FIRST RUN GREAT THE MOTORS WERE NOW BOTH AT 4900 AND THE SPEED UP 3MPH. HERES WHAT HAPPENED WE MADE 3 PASSES THEN SHUT DOWN AND THE MOTOR STALLED THE ONE I JUST FIXED UP. WHEN TRYING TO RESTART IT CRANKS AND CRANKS AND WE HAVE TO HOLD IT HALF THROTTLE TO GET IT TO START AND THEN IT IS LOADED UP BAD, CLEAN IT OUT AND BACK TO IDLE AND STALLS AND STARTS THE SAME WAY HAVE TO GIVE IT ALOT OF THROTTLE TO GET STARTED AND LOADED UP BAD AGAIN. NEVER HAD A IDLE PROBLEM OR LOADING UP PROBLEM. ACTS LIKE A FUEL PROBLEM ,COULD THE EXTRA 500 RS WIPED THE STOCK MECHANICAL PUMP OR WHAT THANKS FOR ANY ADVISE

Pure Energy

vacumm leak? I had a very similar problem.

GPM

How about a timing chain, or distributor gear.

rssteiny

The Boat Still Will Run Ok ,it Is Just A Idle And Starting Problem. Acts Like It Is Loading Up, Was Also Thinking Carb Problem Like A Float Or Needle Seat Not Closing Off The Fuel.

Vacuum Problem Is Possible

GPM

Why was the timing off by 16 degrees, did it move again.

blue thunder

Switch carb to other engine and try. Sounds like a blown power valve if holley carbs.

BT

JJONES

Power Valves Blow Right Away If It Back Fired When The Timing Was Off.why Was The Timmming So Far Off?i Have Seen Distributor Shafts Twist At The Oil Pump Connection And Have Also Seen Them Brake!electronic Ignition Or Points,vacum Advance Or Electronic Or Machanical