1986 120 hp tries to die

[wolflb2]

I'm weak on my motor knowledge and only know enough to do very basic stuff. I decarbed with seafoam since it sounded easy enough and after following directins and letting it set for an hour I went started engine on muffs and the best way I can describe it is it ran irregularly. How do you type a sound???? Kind of a VRRRRMMM pause VRRRRMMM pause. Another split second and it would have died but it catches with power. Speeding engine up merely put more power and louder VRRRMMM and longer pauses. <br />OK so I had heard that if you have a bad plug wire that may be arcing you can spray an electronic cleaner onto it and will seal itself up. Sprayed on wires and it caught and ran great for about 10 seconds, so just kept spraying individual wires hoping to isolate which wire. No luck. But I did spray a cluster of wires at the top rear of engine that got it to run smooth for about 2 minutes. Then back to VRRRRMMM. I finally shut engine off after about 10 minutes of messing with it this way.<br /><br />HELP! I had this sound once before and took it mechanic and it wouldn't do it for him and when I dot home it wouldn't do it for me either. I doun't think I want to rely on my cure being hauling boat to mechanic and then hauling it home. Its cheap but unreliable.

 

[ob]

Re: 1986 120 hp tries to die

Check all of the engine ground lugs and insure that they are clean and tight as well as performing a visual on all wiring from power pack to coils and from coils to plug leads.If the engine was running fine before the decarb procedure ,you may have fouled one or more sparkplugs.They'll also neede to be removed and either cleaned and regapped or replaced.

 

[Walker]

Re: 1986 120 hp tries to die

When I decarbed my 94 120 last year it messed up all 4 of the check valves in the recirculating system. <br />When you sprayed the electronic cleaner the engine probably picked up the propane propellant and ran on it for a moment.

 

[ob]

Re: 1986 120 hp tries to die

Good observation Walker.The contact cleaning of the plug leads settling the engine out didn't register much with me.Symptom does sound more like what you had happen or even a fuel restricted carb issue.

 

[wolflb2]

Re: 1986 120 hp tries to die

I'll put in new plugs tonight and have already checked the grounds, but whats the fix for the check valves?<br /><br />Thanks for the help!

 

[Walker]

Re: 1986 120 hp tries to die

The check valves have to be either cleaned or replaced. I had success cleaning 2 of mine but 2 had to be replaced. Carb cleaner is what I used.

 

[rodbolt]

Re: 1986 120 hp tries to die

careful with that axe eugene.<br /> any way at least quit spraying flammables at the plug wires. your lucky the wires were not arcing. if they were you would have seen a flash and heard a whoosh. who knows you may have made the news.<br /> test the recirc check valves and carb air jets. <br /><br />decarb should be done regularly or not at all. my 85 120 has not had one since I put a piston in it in 1995. my charity crabber has a frankenstien 140 looper I built in 98 that has ran more than 12 thousand gallons of gasoline through it with walmart oil and never seen a decarb. and its still VRO.<br /> decarb spray is way overrated and can cause problems if done irregularly. either do it every 100 hours/anuually or dont do it at all.<br /> good luck and keep posting

 

[wolflb2]

Re: 1986 120 hp tries to die

Finally got a chance to work on it again today. It was the spark plugs!!!! Pulled the old ones cleaned and restarted and ran fairly smooth. When it quit smoking I pulled the old ones and put clean new ones in and it was smooth. Kind of odd though, checked the old plugs (gapped by mechanic during tune up) and they were supposed to be at .030 but they were; 022, .032, .040, .044. He doesn't have my confidence any more!

 

[wolflb2]

Re: 1986 120 hp tries to die

Thanks ob, Walker, gald I didn't have to do anythngwith check valves. rodbolt - I never thought of flash fire so I wont do that any more. Oh, the motor was decarbed last year by mechanic and I decided I would start a routine of decarbing it. <br /><br />Thansk again, you all saved me some bucks and I slept better last night!