1976 85hp seahorse miss in engine

[Jessie0007]

Hello, I have a 1976 85hp Johnson 4v seahorse outboard and have a problem with a miss in the engine. It really seems to only do it at idle or 900-1000rpm, that is the lowest the engine idles? No, idle adjustment screws on the carbs? I am not sure if it will do it at higher rpms because I have never had this motor in the water. Anyhow, I have cleaned both carbs, tried different plugs, the spark seems fine, jumps over 1/4" without any problems there. Only other problem is that all the plugs are wet. I don’t know if this is the problem with the miss in the engine or how to adjust the fuel to the plugs. Usually the engine just misses and picks back up again but sometime it will quit altogether. Only other noticeable defect was a small crack in one of the ignition coils but I filled that up with epoxy, does not seem to effect the output of spark but seeing that all my plugs are really wet/oily I am assuming that is not the problem. Also, I am not sure if the engine is getting up to full operating tempeture, I can touch the heads and they are warm but I can keep my hand there after running for 10 minutes or so. Any help on this matter would be appreciated! <br /><br />Thanks, <br />Jessie00721

 

[MCM]

Re: 1976 85hp seahorse miss in engine

Jessie,<br /><br />spark should be 7/16" strong, blue and snappy, anything less indicates a potential problem, if you have cracked coil its time to replace, (personally I would replace all of them), epoxy is not a fixall for failing electroncs. Also what plugs are you using and what is the gap? plugs should be Champion L77J4 or equivalent gapped .040, <br /><br />As for the oprerating temp you should check/replace your t'stat, someone may have removed it or it could be stuck open.<br /><br />As for the carbs, cleaning is good but a carb kit is better. Reusing old gaskets leads to air/vacuum leaks. <br /><br />Hope this helps and post back

 

[mikeyzx2]

Re: 1976 85hp seahorse miss in engine

Hey Jess, go with what MCM is telling you, that's good basic advice starting off. I'm fooling with my '77 85hp still, so I'll add a couple things to this that I've run across so far.<br /><br />It don't matter how small the cracks are in the coil coverings. They're made much better nowadays so yank them out. Take a look under the flywheel...if you see any black stuff that's dripped out, the stator's gone belly up. That's where I'm at now. I have spark probs and found the culprit. The motor would run, but missed at idle alot of times. <br /><br />Take the carbs and make sure you clean them thoroughly and use kits like MCM said. And make sure the float's are set correctly also.