Mercruiser 470 3.7L stalls

[BrianD1973]

1986 Cheetah -stalls from time to time when going from idle (not neutral although in idle for maybe 1 or 2 seconds) to full throttle (ie. when starting a skiier). Only happens maybe 1 out of 10 or 20 times.... usually just before it stalls I bring it back to neutral and try again and it may do it again.... the way I've gotten around it for now has just been to bring throttle up a little bit slower... .then seems to be fine for another 19? or so attempts.... just a niussance when it happens.

thx, Brian

 

[Eric 3.7LX Alpha 1]

Re: Mercruiser 470 3.7L stalls

Could be some buildup in the bellhousing where the lower shift cable slide moves in and out, causing additional tension on the cable activating the cut off switch.

You would need to have someone back there and see if the cut off switch moves off center when this happens to know if it is lower cable related. The cutoff switch should only move off center and activate when shifting out of gear back to neutral- only.

Eric

 

[BrianD1973]

Re: Mercruiser 470 3.7L stalls

Hmm, I'm more auto mechanic related... little lost on what you are saying.... was thinking maybe some kind of intake leak?

Just to make sure we are on the same page, this is a problem accelerating, not shifting into neutral or shifting at all... just seems to want to completely stall if I don't back off the throttle... actually will backfire a little too at times..... ????

 

[BrianD1973]

Re: Mercruiser 470 3.7L stalls

and just to clarify.... the backfiring only happens when it wants to do this stalling thing.... otherwise everything runs fine.... skiier sitting in water... yells hit it... i take up the slack with a 1 second idle (taking it out of neutral)... then gun it! starts to acc for a split second and then backfire and stall... if I pull back the throttle before it stalls completely, it will stay running.... tell skiier a minor problem.... double check readiness.... and pull the throttle up just a tad slower and seems ok.... then can go back to other attempts by gunning it!

???

 

[bruceb58]

Re: Mercruiser 470 3.7L stalls

Sounds like your carb's accelerator pump is not working properly and/or your carb is running on the lean side.

No carbed boat is going to like just slamming the throttle down though...it will always go lean under than condition hence the carb backfire.

 

[BrianD1973]

Re: Mercruiser 470 3.7L stalls

ok... sounds reasonable... thanks for the ideas... so far doesn't seem an issue to investigate much further.

THX!
Brian