96 mercruiser 4.3 won’t pull above 4000 RPM

[Mithan]

Tried to adjust choke, tack will go to 4k at 3/4 throttle. When pushed all the way it drops to 3700 and smells like gas in the exhaust. Any ideas?

 

[achris]

Hello and welcome to iboats.

First thing I'd be doing is a full tune. Check compressions, new spark plugs and wires, new rotor and dissy cap. Then play with the carb.

Also, '96 Mercruiser 4.3' doesn't really tell us much. 1996 was a 'crossover year' for the 4.3. Is it vortec or non-vortec? (valve covers won't tell you that. You need to look at the intake manifold bolts). 2bbl carb or 4 bbl?

What would really help is the engine serial number. If you're not sure where to find that, have a read of this...

Where to find Mercruier Stern Drive and Engine serial numbers.

Stern Drive serial numbers. (Continue down to the next posts for engine locations) ---------------------------------------------------------------------------------------------- All Mercury Marine serial numbers follow a particular format, be they Engine, Drive or Gimbal housing. Up to about...

forums.iboats.com

Chris......

 

[Mithan]

Hello and welcome to iboats.

First thing I'd be doing is a full tune. Check compressions, new spark plugs and wires, new rotor and dissy cap. Then play with the carb.

Also, '96 Mercruiser 4.3' doesn't really tell us much. 1996 was a 'crossover year' for the 4.3. Is it vortec or non-vortec? (valve covers won't tell you that. You need to look at the intake manifold bolts). 2bbl carb or 4 bbl?

What would really help is the engine serial number. If you're not sure where to find that, have a read of this...

Where to find Mercruier Stern Drive and Engine serial numbers.

Stern Drive serial numbers. (Continue down to the next posts for engine locations) ---------------------------------------------------------------------------------------------- All Mercury Marine serial numbers follow a particular format, be they Engine, Drive or Gimbal housing. Up to about...

forums.iboats.com

Chris......

2bbl, thank you for the input! It’s already been tuned and compression is good.

 

[achris]

Then I'd be pulling the carb off and rebuilding it completely. 2 bbl Rochester/Mercarbs are easy to do, as long as you follow the Merc factory manual.

Chris...