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85. Just doesn't make sense

K

keithm

Contributing Member
1976. Johnson 85
this thing has been sitting for 3 years. So here's what I did. Cleaned the carbs , flushed the fuel system replaced the plugs, set the wot timing after replacing the number 1 coil, which had cracked and was open. Started it up it had a bad miss at idle after a frustrating electrical search I found the red wire on the regulator was broke, so I replaced it. Still had a miss. Backed it into the water so I could make adjustments with a load. Fired right up with no miss, after a thorough warm up I backed out and went around the lake, ran like a dream super smooth and very strong ran for about 15 minutes. Idled into the dock, wife wanted to go so I went to back up put it in reverse it died. It would restart but would not take throttle, idle was very inconsistent. Pull it back to the house fired it up again and started pulling plug wires 1 and 2 made no change 3 and 4 and the engine died. Ran a compression check. 132 lbs all four cylinders. Next I examined the reeds all perfect. So I have spark, I have compression, fuel system is clean, reeds are intact. My thought is that since1 and 2 are the issue, could it be the top carb? By the way, charge is 13.89 at idle with new regulator. Anybody have any experience with anything like this.
 
If pulling the plug wires on # 1 2 made no difference then you must not have spark on them, get that staraighented out and see what happens. Good luck
 
Are you checking that spark with an open air spark checker and is it jumping a 7/16th gap? You said that pulling spark wires on # 1&2 made no difference so they may not be sparking under compression. Others should chime in. Good luck.
 
your compression is ok..so the decision is it fuel or fire?...check the fire as will said and if ok then address carb.
 
Plugs are wet which would indicate no spark, I have a open air tester at the shop, I'll check that and get back to you.
i am curious , if the plugs are not firing under compression wouldn't that indicate an air gap issue on the timer base, and if that we're the case wouldn't that affect all 4?
 
No it does not.------Spark will jump across a spark plug at atmospheric pressure but it takes a lot more voltage to jump the 0.030" gap in the cylinder when air is compressed to 132 PSI.
 
Open spark test to 7/16, bright blue spark all for cylinders. In the process of cleaning all electrical connections.
What's next? Thanks for all the help
 
Had a 115 hp in early 80's, same problem, only one bank firing, mech. tested engine, 1/2 bad power pack, new power pack and engine runs good on first start, turned key off, tried to start again, only one bank firing, the problem- shorted kill wire, new power pack again, all good for years, choked engine to stop it till i sold it
probably not your problem, just say'n
 
keithm said:
1976. Johnson 85
this thing has been sitting for 3 years. So here's what I did. Cleaned the carbs , flushed the fuel system replaced the plugs, set the wot timing after replacing the number 1 coil, which had cracked and was open. Started it up it had a bad miss at idle after a frustrating electrical search I found the red wire on the regulator was broke, so I replaced it. Still had a miss. Backed it into the water so I could make adjustments with a load. Fired right up with no miss, after a thorough warm up I backed out and went around the lake, ran like a dream super smooth and very strong ran for about 15 minutes. Idled into the dock, wife wanted to go so I went to back up put it in reverse it died. It would restart but would not take throttle, idle was very inconsistent. Pull it back to the house fired it up again and started pulling plug wires 1 and 2 made no change 3 and 4 and the engine died. Ran a compression check. 132 lbs all four cylinders. Next I examined the reeds all perfect. So I have spark, I have compression, fuel system is clean, reeds are intact. My thought is that since1 and 2 are the issue, could it be the top carb? By the way, charge is 13.89 at idle with new regulator. Anybody have any experience with anything like this.
Click to expand...

I agree, problem most likely is that top carburetor. You must have missed something in there. I don't think that motor has a voltage regulator does it? You must mean rectifier. Since it is unregulated, voltage will often go 16V or higher. That's just the way it is. Unless you bought one of the new regulated rectifiers.
 
Ok cleaned all the connections and I do mean all, light sanding, contact cleaner and dielectric grease, there is a ground wire on the 2 4 side of the motor just behind the solenoid, it was bolted to the same stud as the ground lead back to the battery, it was not broke, but the insulation was crumbled and the wire was oxidized bad, traced it back into the harness till there was no oxidizing cut it and replaced the lead all the way back down. I hooked up the hose and it fired up ran smooth. Tomorrow I'll get it out on the lake and see how it goes, Thanks everybody. Great info, I'll keep you posted.
 
Ok took the boat to the lake. Started up quickly , warmed it up and went out ran for about an hour and a half with no problems. I had set the idle at 800 so that when I put it in gear it would drop to about 500 that seemed pretty close still had to idle up just a bit. Is that anywhere close. The manual basically says. Set idle.
thanks everyone I really appreciate the help. It seemed to have been a bad ground
 
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