79' Johnson 140,runs great at home,wont strart on the lake?(HELP PLEASE!)

VA.LAKEMAN

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Joined
Apr 3, 2008
Messages
28
I think this is the worst time Ive ever had figuring a problem out,so again,I will turn to you great folks for help.Anyway,I follow the exact starting procedure at home in the tank,the boat fires right up and runs flawlessly.Perfect through all r.p.m.'s and have let it run for 20-30 min. like this and it starts right up and runs great......AT HOME.Now same boat,same exact starting procedure at the lake.Runs flawlessly,only after fishing for a hour or so and deciding to relocate will it give me a hell in a handbasket of a time to re-start.It will start and run perfect at idle,but when I put it in gear and try to move it will stall right out.After several attemps of restarting,while it sounds so close to starting again but just doesnt.....now it will fire up and decide to go.I think it is giving a flooding type of symtom but Im not completely savy with this engine.Could somone please give me there opinion on what there thinking it could be or where I should start looking.....Thanks in advance

I guess what is driving me crazy is,if it were truly flooding,then why does it only do it on the lake and not at home???.....:facepalm:
 

emdsapmgr

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Dec 9, 2005
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11,551
Re: 79' Johnson 140,runs great at home,wont strat on the lake?(HELP PLEASE!)

Re: 79' Johnson 140,runs great at home,wont strat on the lake?(HELP PLEASE!)

It's either a fuel or spark issue. It's easy to check for spark when the engine is warm and won't fire. Remove the cowling and put an inductive timing light on each of the 4 plug wires. Crank the engine. The light will show flashes from the plug wires and show you the quality of spark. If it's good on all 4 wires, then you have a fuel problem. (Keep in mind that weak ignition componets tend to fail when the engine heats up to normal operating temps.) Always possible the carbs are out of fuel upon a hot restart. When it fails to restart, prime the fuel hose bulb. That will force extra fuel into the carb bowls. Then try to start it. If this works, then the carbs may be draining of fuel when it is shut off when warm. That could be due to an air leak in the fuel system or other issues, like a bad anti-siphon valve in the tank.
 

5150abf

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Aug 12, 2007
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Re: 79' Johnson 140,runs great at home,wont strat on the lake?(HELP PLEASE!)

Re: 79' Johnson 140,runs great at home,wont strat on the lake?(HELP PLEASE!)

Just an idea but maybe don't choke on your restart, it may not need the choke to run, I normally just advance my timing and try it, if it doesn't start I will tap the choke.
 

VA.LAKEMAN

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Apr 3, 2008
Messages
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Re: 79' Johnson 140,runs great at home,wont strat on the lake?(HELP PLEASE!)

Re: 79' Johnson 140,runs great at home,wont strat on the lake?(HELP PLEASE!)

Thanks alot guys for the responces.As far as the choke apon restart,Ive already ruled that out as Ive tryed it both ways several times.However I will check the spark as soon as it warms up a bit this morning and go from there.Again thanks for taking time out of your day to offer your help!;)

p.s.,
I tested the comperssion last night and had 125 across the board,one more thing ruled out I guess.
 

emdsapmgr

Supreme Mariner
Joined
Dec 9, 2005
Messages
11,551
Re: 79' Johnson 140,runs great at home,wont strat on the lake?(HELP PLEASE!)

Re: 79' Johnson 140,runs great at home,wont strat on the lake?(HELP PLEASE!)

That's solid compression on that engine.
 

rdprttt

Cadet
Joined
Feb 2, 2009
Messages
12
Re: 79' Johnson 140,runs great at home,wont strat on the lake?(HELP PLEASE!)

Re: 79' Johnson 140,runs great at home,wont strat on the lake?(HELP PLEASE!)

I just posted almost the exact same thing.

did you figure this out?

mine is in the shop....
 
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