Drop in RPM's

[495v]

My 5.7L mercruiser is not getting up to the RPM range that it was. I recently installed an on-board battery charger. Is it possible that I knocked a wire loose and am only running on 7 cylinder's? I know it's propped right. What else should I check. The engine is not whining or anything. It seems to be running perfectly normal. Any suggestions. Was running at 4200-4400 RPM and now I'm only getting 3500-3800 RPM.

 

[495v]

Re: Drop in RPM's

Bump......<br />Could my tech be off?

 

[jeemtp_99]

Re: Drop in RPM's

1) I would check the plugs make sure they are not fouled. 2) Check all the plug wires to make sure they are not grounding themselves on the engine itself. You shouldn't get a shock from them if you touch them when the engine is running. 3) If it has a distributor cap i would check that for any cracks or burnt spots on the inside of it. 4) Also check where the plug wires plug into the cap. Sometimes corrosion builds up in there 5)Maybe even check the fuel filter. These are the simple things i can think of. I hope it helps.<br />Jason

 

[495v]

Re: Drop in RPM's

Bad tach was the culprit. I calibrated it but is still a little off. Plan on replacing it in the near future.