My '95 Johnson 225 coughs too, but no backfires, eventually dies. Starts back up.

[btravlin2]

Thought it best to start another thread. This motor idled rough before the carb/throttle rebuilds and only improved alittle afterwards. Runs like a beast above 1000rpms.

After running awhile at high speeds it has particular trouble idling. No backfires, just idles, then coughs, then dies. And it hesitates/dies on acceleration....acts like it's flooding. After babying it I can slowly transition back up to high speed.

I've got all the low-speed screws set at 5-3/4 turns, which works great when cold, but problems set in after warming up.

I have new plugs, filters, fresh gas.

What would be the likely chronology to work through on troubleshooting?

Thanks.......

 

[boobie]

Re: My '95 Johnson 225 coughs too, but no backfires, eventually dies. Starts back up.

Have you checked out the oil recirculation system on it yet?? This can also cause a bad idle if it's not working properly.

 

[James R]

Re: My '95 Johnson 225 coughs too, but no backfires, eventually dies. Starts back up.

Could be fuel pump problem. Try pumping the primer bulb when it is acting up and see if it makes a difference. If it does then suspect fuel pump.

 

[btravlin2]

Re: My '95 Johnson 225 coughs too, but no backfires, eventually dies. Starts back up.

Could be fuel pump problem. Try pumping the primer bulb when it is acting up and see if it makes a difference. If it does then suspect fuel pump.

Being that the fuel pump is 18 years old, I suspect the diaphragms could be disintegrating due to ethanol. It's expensive, but I think I'll replace it. I like the auto oil mixing feature.

 

[daselbee]

Re: My '95 Johnson 225 coughs too, but no backfires, eventually dies. Starts back up.

Go to 6-1/2 turns out. Make no other adjustments. See what happens. Do you trust the person who did the carb job to have done it correctly? If it is bogging off idle, it could be fuel starved for some reason. And here we are, back to the carb job.....

 

[btravlin2]

Re: My '95 Johnson 225 coughs too, but no backfires, eventually dies. Starts back up.

I did the carb/throttle job, and if it could be done better, I don't know how. But here's the clue as I see it, and I made a mistake above in the original explanation of symtoms.

The motor idled rough and died before the rebuilds. The first time in the water after, it purred at idle with 5-3/4 turns. Accelerated beautifully with no hesitation. I thought I had it. But after running at cruising speed for an hour it went back to the same old idle problems.

Yesterday I talked with a long-time mech who knows these motors and these fuels pumps well. When he heard that it idled well after the rebuilds, but then regressed after the cruising, he suggested the 18 year old diaphragms were shedding some contaminants that fouled the low speed screws again. I've read alot about these pumps, and while reliable, they are just as susceptable to age and ethanol as any other part.

It makes sense to me, so I'm going to go ahead and replace it, and clean the carbs again.

 

[daselbee]

Re: My '95 Johnson 225 coughs too, but no backfires, eventually dies. Starts back up.

Well, please be sure to post the outcome. I am very interested to see if you find anything in the idle circuits. I guess the same problem can and eventually will exist regarding the molded fuel hoses from the distribution manifold to the carb inlets. I always suspected them of deteriorating.

 

[jerryjerry05]

Re: My '95 Johnson 225 coughs too, but no backfires, eventually dies. Starts back up.

Compression?
All plugs burning right?
You can install a cheap see through filter from the pump to the carbs.
Wally World G-2 G-12
If you rub/squeeze the hose and it feels real soft, then E is probably melting them.

 

[James R]

Re: My '95 Johnson 225 coughs too, but no backfires, eventually dies. Starts back up.

If you are happy with the oiling system it would be way less expensive to simply rebuild the fuel pump. There should be a relatively inexpensive rebuild kit available. I did with my 93 150. Try Max Rules for the kit and info.

 

[w2much]

Re: My '95 Johnson 225 coughs too, but no backfires, eventually dies. Starts back up.

Just my 2 cents, but 18 years old is 18 years old. If you rebuild the fuel side you still have an 18 year old oil pump. If you can afford it buy the new pump for peace of mind. My oil side went bad and cost me the motor. It is the heart of the engine, lean fuel or oil and you are done.