1968 Evinrude 9.5 sneezing coughing and quits

[thursty]

68 Evinrude 9.5 runs great at higher speed but just won't run at low idle or trolling speed. Coughs, knocks/thumps and dies

What I've done so far
- new coils and points
- new fuel pump
- clean and rebuild carb
- new fuel lines
Running on 50:1 fuel
Cover on or off no change in performance
Adjusted low speed all the way in til seated and turned back 1-1/2 turns
Low speed adjust does nothing for it

Thanks for any help. I do appreciate it.

Tried to upload 24 sec video but it won't work.

 

[Rick.]

You could try opening the low speed more than 1 1/2 turns. Sounds like it could be running lean at low speed. If adjusting the needle beyond 1 1/2 turns has no outcome you may need to clean the carb some more. Best of luck. Rick.

 

[boobie]

You should probably go back through the carb again.

 

[thursty]

Thanks - Will remove the carb again. Soaked it in NAPA carb cleaner can for 4 days and blew it out with 50PSI. Is there a specific area I should concentrate on?

 

[racerone]

High speed jet ( orifice plug ) that is screwed into the float bowl.----About 5/8" long brass.-----And adjustments to make sure throttle does not open too early.----Did you replace condensers ?

 

[Michawilden]

Check the low speed needle, It could be that the tip is broken and clogs the passage. Then it will not run on low revs.

 

[Crosbyman]

Thanks - Will remove the carb again. Soaked it in NAPA carb cleaner can for 4 days and blew it out with 50PSI. Is there a specific area I should concentrate on?

the 9.5 carb kit does not include those little white plastic parts in the low speed chamber if you want to clean the carb they need to be pulled...and probably damaged so new ones must be ordered

read leroy's article closely it explains the issue

http://www.leeroysramblings.com/OMC_9.5.htm

There is no aftermarket carburetor kit available for these motors. The BRP part # is 0382048, which includes the float. Available for $30.96 as of 5-2013. I am disappointed in this kit. It comes with, (like most) repair parts for both the early and late carbs but does not come with everything. On this carburetor, there is a 1/2" core plug on the outer part of the carb that is inline with 3 small holes in the carb throat. These holes had to be drilled through the access hole this core plug covers up. However INSIDE and under the core plug is a plastic filler plug #0312909 that is not included. On the one I repaired, it would be impossible to remove this plastic plug without destroying it.​

the side knob for low speed adjustment may be set to low ….turn it up a bit you will see the tiller throttle rotate as you adjust the side knob


by the way does it idle ok when the cowl is off the motor ?? inner exhaust leaks have been known to suffocate the engine...

 

[kbait]

I have worked on 3 of there that would lean sneeze at low idle after normal carb clean.. couldn’t open LS needle enough to get proper fuel. Replaced carb on first one=success. Next 2, I pulled the low speed needle and bowl plug out (carb installed) and blasted air directly into needle port w/compressed air (nozzle extension on hose). Worked both times!
I saw no other way to try to clean that chamber with that plastic piece..

 

[thursty]

kbait - Thats what I will try next. Thanks very helpful input. Much appreciated

 

[thursty]

Crosbyman I have noticed that plastic plug and couldn't figure out how to remove it so left it alone. Will try to find replacement part.

Also the cowel on or off doesn't make a change in performance.

Thanks

 

[thursty]

Michawilden - removed the needle - it looks good with no notches or rings or broken parts. Thanks for the suggestion.

 

[thursty]

racerone - is that a replacable jet? don't want to dig around in there if it is pressed in. Yes - coils, condensers, points and wires. Thanks for the tips. Still working on solutions

 

[racerone]

I said it was screwed in.

 

[Crosbyman]

9.5 carb utubes

https://www.youtube.com/watch?v=r-VTkOuSg00

https://www.youtube.com/watch?v=Y2pwU5aho9U&t=191s

 

[thursty]

Thanks everyone