Engine hesitates/stalls and backfires

[tmh]

Well, I have several thread dealing with my 1985 200 hp mercruiser alpha one 2bbl Chevy 305 not producing quite the power it should, and the mechanic will be looking at some of the suggestions I rec'd here soon (I hope), But in the meantime, we were out yesterday and I just want to add that I am experiencing hesitation/stall if I try to "punch it" on takeoff such as for water sports, etc. It also backfires some times when doing this.

I can get it past the stall if I accelerate slower and carefully. And it seems to get less pronounced once it's been running for a long time, but still can stall.

Does this point to any specific issue? Acclerator pump? Missing on a cylinder?

Also, how would I go about checking if i have one bad cylinder/plug? By this I mean can I, while underway, pull the wires off the plugs one at a time and see if the rpm/speed drop is similar for all or if one has less effect (would point to that beeing the proplem area)? Is there a safety issue that makes this a bad idea?

Thanks as usual.

 

[Haut Medoc]

Re: Engine hesitates/stalls and backfires

Well, I have several thread dealing with my 1985 200 hp mercruiser alpha one 2bbl Chevy 305 not producing quite the power it should, and the mechanic will be looking at some of the suggestions I rec'd here soon (I hope), But in the meantime, we were out yesterday and I just want to add that I am experiencing hesitation/stall if I try to "punch it" on takeoff such as for water sports, etc. It also backfires some times when doing this.

I can get it past the stall if I accelerate slower and carefully. And it seems to get less pronounced once it's been running for a long time, but still can stall.

Does this point to any specific issue? Acclerator pump? Missing on a cylinder?

It does sound like an accelerator pump problem....
Pull off the flame arrestor & pump the throttle...
You should see two streams of fuel.....​

Also, how would I go about checking if i have one bad cylinder/plug? By this I mean can I, while underway, pull the wires off the plugs one at a time and see if the rpm/speed drop is similar for all or if one has less effect (would point to that beeing the proplem area)? Is there a safety issue that makes this a bad idea?

No, that is a good way to check ....
Just be sure to keep clear of moving parts.....
You could do the test at the dock, but under load would be best....​

Thanks as usual.

Tie it to the dock securely....​

 

[tmh]

Re: Engine hesitates/stalls and backfires

So, just to be clear, it IS safe to pull off one plug wire at a time while the engine is running (yes, assuming I stay clear of moving parts)? Not an electical shock issue?

Thanks. I may try that this week if it's OK to do.

 

[frayed knot]

Re: Engine hesitates/stalls and backfires

Get a rubber glove, it will shock the be-jeepers outta ya.

 

[tmh]

Re: Engine hesitates/stalls and backfires

Get a rubber glove, it will shock the be-jeepers outta ya.

Well, will it still shock me with a runner glove? Can it arc across a distance to zap me? Or does a dry, rubber glove do the trick?

Thanks.

 

[Windykid]

Re: Engine hesitates/stalls and backfires

Insulated pliars work well.

 

[Robj]

Re: Engine hesitates/stalls and backfires

I would use gloves and insulated pliers. Pull one wire off at a time while the engine is at idle, rpm drop = cylinder is firing, no change in rpm = bad cylinder. I would also check the timing and make sure the chain has not skipped.

Good luck,

Rob

 

[Coors]

Re: Engine hesitates/stalls and backfires

Wimps, just grab it; the jolt is good for blood circulation