engine sneezing and stalling at idle

[donald_warnock]

I have a 1976 85hp johnson.Last thursday night I went fishing,and when we came back to the dock the next morning to load back on the trailer the motor kept sneezing and stalling out when I was at an idle waiting to load it back on the trailer.I just got this motor a month ago,so I dont much about the history.It was gave to me.I had to replace the fuel pump from damage due to the motor sitting up.I also took the carbs off and cleaned them.They had a little rust in them,this is what led me to check out the fuel pump.I also replaced the rectifier,due to a charging problem.It tested bad.The stator checked out good.Compression is good on all cylinders.120 on 1,2,&3.110 on #4.

 

[MCM]

Re: engine sneezing and stalling at idle

Don,<br /><br />Did you chack to see why the carbs had rust in them? I think you need to investigate your fuel delivery system, such as the tank, fuel line, connections etc. Has/did the tank have water in it? also the carbs could probably stand a complete overhaul (rebuild kits), a cleaning isn't generally quite as thorough. The sneezing is an indication the motor is running lean, blocked fuel passages, jets, etc.<br /><br /> EDIT: using old gaskets is not recommended either it opens up the possibility for vacuum/air leaks

 

[donald_warnock]

Re: engine sneezing and stalling at idle

The rust came from a rusted check valved in the fuel pump.That is why I replaced the fuel pump instead of rebuilding it.The tank is a plastic 12 gallon tank,and the fuel line is new.When I cleaned the carbs I made sure I cleaned the jets thoroughly,but maybe i need to invest in a rebuild kit.Will I need to purchase two kits,or will one kit take care of both carbs?

 

[RJDAWSON]

Re: engine sneezing and stalling at idle

76johnson man,you'll need a kit for each carb. The bowl gaskit gets brittle and needs to be replaced. I guess that you checked the ohms reading on the stator, but check for anything that would look like driping tar or is it stickey? That would indicate that its been hot and should be replaced.<br />MCM, has been great help to me I'm sure he will be to you.<br />Zeke

 

[MOETOROLA]

Re: engine sneezing and stalling at idle

bad reed valve could cause sneezing, hold a busness card infront of the carb about an inch away, and see if you get gas spray on it, when it sneezes.

 

[duke3]

Re: engine sneezing and stalling at idle

76johnson man, dont forget the plugs. Are they new ?

 

[ezeke]

Re: engine sneezing and stalling at idle

I had that once on my 76 115 shortly after I put the carbs back. <br /><br />Found that the carbs were not sealing tight against the manifold so air was coming in. <br /><br />Retightening the carb bolts did it.

 

[MCM]

Re: engine sneezing and stalling at idle

I agree, the sneezing sounds like an air/vacuum leak which would cause it to run a little lean. definately install new gaskets in the carbs and make sure you have a tight seal at the manifold.

 

[donald_warnock]

Re: engine sneezing and stalling at idle

Thanks guys.Ill try all of your suggestions this weekend and let you know how it went.Duke the plugs are one of the first things that I replaced,thanks for the tip any way.Ive had a couple of boats over the last 12years,and ive always done all of my own maintenance,but im no boat mechanic.I can do any thing that needs to be done an a vehicle,and i also drag race.Ive fooled around with motorcycles and atvs also.Now I guess its time to learn about outboards.

 

[TxShorty]

Re: engine sneezing and stalling at idle

Another thing you need to make sure of is carb sync. If either carb isn't fully closed at idle, you'll get a similar cough. I couldn't hear the difference in this cough and a lean cough either untill I'd worked on two strokes for a while.