1994 Johnson 130hp, rev's up and down and cough's/sneezes at idle

[Timbo007]

Mod No- AJ130TXERR

I took it for a 60mile trip to catch some kingfish. All seemed good until I went to flush the outboard on the driveway.
At idle it seems to climb in RPM, cough, then drop RPM. They say a picture is worth a thousand words so I took a video of it running and posted on You Tube hoping one of you guys out there could please offer some advice.

http://www.youtube.com/watch?v=EUng8gUkc3o

I have already wasted $230 on a mechanic who seems to have achieved very little :-(
Thanks in advance for your words of wisdom.

 

[levi_tsk]

Re: 1994 Johnson 130hp, rev's up and down and cough's/sneezes at idle

well theres deffinitely SOMTHING going on there .... that aint normal
what did the mechanic say he did?
what all have you checked?

ok so lets start simple ....

make sure you dont have fuel leaking anywhere do this by pumping up the primer bulb with the hood off the motor

check and clean the fuel filter

change the plugs -take a pic of of the old ones before you throw them out (it helps diagnose whats going on )

check the spark you want it throwing a hot blue spark about a half an inch long use a spark checker with an ajustable gap 5 bux at advance auto parts or autozone if you dont have one

do all this and if anything is out of the ordinary post up pics the video was a REALLY GOOD IDEA btw

 

[kenmack]

Re: 1994 Johnson 130hp, rev's up and down and cough's/sneezes at idle

Just went thru a similar situation with a '98 Johnson 130, but ours wouldn't idle for that long. Ended up replacing the VRO as it had appeared to quit working all together. Also replaced the plastic carb bodies because the mechanic that went thru them to replace gaskets didn't set the screws right in the plastic and ended up cracking the bodies (they were sucking in a little bit of air).

FWIW, we bought our VRO from duskyonline.com out of Florida - $379 including overnight shipping to Tx. Best deal I found.

 

[whatley]

Re: 1994 Johnson 130hp, rev's up and down and cough's/sneezes at idle

This probably will not be the answer you are looking for or the possible solution however this just happened to me. That video is EXACTLY, not similar but EXACTLY, what my engine did when on the muffs on land. When I then ran the engine in the bay the idle issue went away. I have a 1992 120 V4.

 

[levi_tsk]

Re: 1994 Johnson 130hp, rev's up and down and cough's/sneezes at idle

have you tried pumping the primer bulb while its doing this?

 

[Timbo007]

Re: 1994 Johnson 130hp, rev's up and down and cough's/sneezes at idle

Thanks for your replies. So far I have checked filters for contamination/h2o (filters,primer bulb and fuel line are only a few months old) fitted new primer bulb, fitted new spark plugs, fitted (then returned) new powerpack (no difference), compression tested (all around 140), good spark on a tester, removed carbs & inspected/cleaned (but were already spotless), removed reed valves ( seem to be functioning well, BUT noticed blackening on the No4, bottom port-side cylinder. The spark plug on this cylinder was also very sooty/dry, the other three were wet/black looking), Spark plug boot removed on No4 while running and engine smoothed out. Something going on here, but ...what. Just as well I have no hair to pull out ! Have not been down the VRO road yet.

 

[Timbo007]

Re: 1994 Johnson 130hp, rev's up and down and cough's/sneezes at idle

Forgot to say, yes I have tried pumping primer bulb whilst the engine is running but no difference.

 

[Timbo007]

Re: 1994 Johnson 130hp, rev's up and down and cough's/sneezes at idle

bump