1985 8hp Evinrude help

[88olympic]

I have a problem with my kicker motor that I cannot figure out. It is a 1985 8hp Evinrude. It starts up on the third pull every time, runs great for maybe 20 - 30 minutes and then starts to miss and run real rough and sometimes die, it will always start right up but continues to run rough. After maybe 10 minutes or so it will cough and all of a sudden will run great the rest of the day never missing a beat. Maybe one of you experts have an Idea, I sure don't. It has done this since I bought it about 10 years now. It had very little use when I bought it with the original plugs still in it ( with paint over spray ). I would very much appreciate any ideas.

 

[nwcove]

i would start with a carb kit and PROPER cleaning of the carb...if it hasnt been done in ten years....it needs it! ( it probably could use a water pump also?)

 

[88olympic]

Thanks, I did change out the water pump a couple of years ago, that is fine. How could the carb be so intermitant? As I said it will run fine for hours afterwards.

 

[racerone]

Check all wiring connections.------Take plug in connecters for ignition apart and inspect pins and sockets.

 

[boobie]

You could have something floating around in the carb.

 

[88olympic]

Thanks a lot guys, I'll do it

 

[88olympic]

Well I didn't get very far, anybody know how to remove the air silencer base. Does it come off with the carb? It doesn't look like there is enough room for the carb to clear the mounting studs without removing the silencer base. I took it all loose but it seems to be catching on the bottom, and there is no room in front to pull it forward to clear.

 

[boobie]

Go to shop.evinrude.com and look up your motor. There may be something that you missed. The air box normally comes off easily.

 

[88olympic]

Thanks everybody, it was the silencer seal. I got the carb and went right to the float bowl. There was a spot of rust on the bottom about 1/4" dia.. I'll be able to clean it up. There was a very small amount of particles that I could feel with finger, I guess it doesn't take much.

 

[88olympic]

I got it all back together and it was running perfect in the tank that i set up for about 15-20 minutes, I revved it up, idled, everything looked good. revved it up again and then same old thing, started running rough. Squeezed the bulb no help, pulled choke no help, after maybe 5 minutes it started to run perfect. Could the reed valves be screwing up or maybe the fuel pump? I don't think it is electrical.

 

[racerone]

Borrow a tank and hose from a friend and test run it with them.----Should be simple to figure this out.

 

[boobie]

Put a timing light on each cylinder at a time. When it starts running rough turn the light around and look into it. If you see any black spots, that will indicate an ignition miss.

 

[Vic.S]

I'd suggest cleaning the carb again. Make sure all jets and passages are clean, not just the bowl.

Also check your fuel tank and fuel line.

A defective fuel pump ,or air in-leakage, would be overcome by pumping the bulb. As that made no difference I not suspect the fuel pump or air leaks into the fuel line or connector.

New plugs worth fitting it not replaced recently.

 

[88olympic]

I have used 3 different tanks. I did check all jets and passages, cleaned the whole carb. I will put the timing light on it tomorrow, thats a good way to check ignition. Thanks for all the answers, will update tomorrow.

 

[BruKen]

Ha! You are not the only one with this issue. Mine does it as well, though not as frequently. However with mine it is always the HT leads that go from CDI to coil or coil to plugs. It's like they vibrate loose or something, but no. Still feel tight, pull them off and inspect for arcing carbon deposits etc. Niks, nada, zip. BUT, wiggle them about and reseat them and hey presto.... everything is fine again. Does my head in trying to locate and correct what is going on (not coil breakdown when hot and not HT Cu corrosion either), but I only know the fix. It's sort of like banging an old tv to get it working. Not exactly the correct approach to mechanics. Good luck and if you get to the bottom of it let me know.

 

[88olympic]

I GOT TO THE BOTTOM !!!!!!! I was getting ready to put on the timing light and just checking the wires and sure enough the 2 orange and 1 black wires that go to the coils were rubbing against the head bolt. I pulled it back a little and fired it up. It ran for 50 minutes in the tank without a problem, I tried everything to screw it up but it ran perfect better than ever. I think it is fixed. I would like to thank everyone for all the replies. If not for the timing light trick I probably would not have found it .BruKen, I didn't get to read your post until after I worked on it today, where were you a couple of days ago? I said I didn't think it was electrical, shows ya what I know, thank God for this forum. I will tie and check all wires. Again THANKS TO EVERYONE.

 

[racerone]

Post # 4 mentions to check wiring ???

 

[88olympic]

I know, I sure will do it now....

 

[boobie]

Glad you got it......Thanks for the come back..

 

[BruKen]

Thanks for the comeback. Glad it's sorted