1991 150 Evinrude

[drummerdad]

Motor spits then stalls at idle but runs well when under power. I rebuild the carbs, Tried new power pack and still then same problem. Marina is at a loss and can not spend anymore time on it. This started about 3 weeks ago. Any suggestions will be helpful. Thanks.

 

[jonesg]

Re: 1991 150 Evinrude

need a lot more information.

What rpm does it idle at in the water? (in gear)
what are the compression numbers?
has it been spark gap tested?
have you link/sync'd it?

Look at these pics and compare them to your linkage.
http://bbcboards.zeroforum.com/zerothread/357667-throttle-roller-timing-arm-adjustment-60-motors

 

[drummerdad]

Re: 1991 150 Evinrude

idle rpm in water before it dies is about 700. Changed VRO pump and nothing the bulb empties out. Tried a external fuel tank but same problem. The compression was 90. It has been link/sync. New plug and gaped. Motor is running lean. If you push in the key for chock it will run. replaced some check valves also. Please any help will do

 

[jonesg]

Re: 1991 150 Evinrude

That is a good engine so its worth getting it straightened out.
At this point I'd get the factory service manual and go over everything.
www.outboardbooks.com

baseline everything.

Compression check
spark gap test
linkysinky
Test coils, plug wires, champion plugs only.

I wouldn't take the marinas word for anything, they are flat out busy.

If all the basics check out good and if the compression is ok...
then a few things can cause bad idle,
such as ;
a leaking primer solenoid flooding the manifold at idle.
Leaking vacuum check valve which feeds the fuel pump.
clogged recirculation check valves or their little hoses.

At idle you need to discover whether its lacking fuel or not, a spray bottle with premixed fuel will help, spray into the carb throats and listen to the idle.

A timing light will show whether the spark is intermittent.

So you need some basic tools and the book.

 

[another todd]

Re: 1991 150 Evinrude

jonesg, why Champion plugs only.

 

[emdsapmgr]

Re: 1991 150 Evinrude

When you rebuilt the carbs, did you use an aerosol carb cleaner on all the passages? Did you compare the spray volume through each opening to make sure they all flow properly? Did you pull the jets and check them when you had them out? When at idle (the carb butterflies are closed,) each carb throat gets it fuel through the idle circuits only. You may still have a restriction in one of the idle circuits. Using jones spray bottle technique on each throat may help you compare the idle.