Running a 1995 4.3LX Mercruiser with with a Weber 4BBL carb.
Engine is in great shape, starts right up & idles smoothly. Compression is around 140 in all cylinders. Plugs, cap rotor and wires are new.
Boat isn't getting up on plane well. At wide-open I am only getting 3900 rpm. As it planes off I'll get about 4300 rpm. I should be getting 4800.
Suspecting that at wide open, not enough fuel is being supplied. Electric fuel pump seems OK but I haven't tested anything. It's not noisy so it seems normal in that sense.
I'm thinking of doing a good cleaning of the carb & checking linkage adjustments. I'll also double check that the firing order is correct but I doubt thhat's going to be the problem. While I am at it I'll also connect a vacuum gauge and see it that's in the normal range and steady.
Assuming firing order is all OK, anything particular about 4BBL's I should know about. Things like how to tell when the secondary's kick in, etc? All advice appreciated. Thx.
Engine is in great shape, starts right up & idles smoothly. Compression is around 140 in all cylinders. Plugs, cap rotor and wires are new.
Boat isn't getting up on plane well. At wide-open I am only getting 3900 rpm. As it planes off I'll get about 4300 rpm. I should be getting 4800.
Suspecting that at wide open, not enough fuel is being supplied. Electric fuel pump seems OK but I haven't tested anything. It's not noisy so it seems normal in that sense.
I'm thinking of doing a good cleaning of the carb & checking linkage adjustments. I'll also double check that the firing order is correct but I doubt thhat's going to be the problem. While I am at it I'll also connect a vacuum gauge and see it that's in the normal range and steady.
Assuming firing order is all OK, anything particular about 4BBL's I should know about. Things like how to tell when the secondary's kick in, etc? All advice appreciated. Thx.