1968 3hp Johnson

I can not touch / hear your motor.----Perhaps flywheel is rubbing on the coils and making the chirping noise.

racerone said:

I can not touch / hear your motor.----Perhaps flywheel is rubbing on the coils and making the chirping noise.

Click to expand...

I'm betting on the carb. probably put 4 or 5 hours on it this weekend, I'm going to run it some more with the 24:!1 gas, and just set it at some steady trolling speeds, and see how consistent it runs, and check the plugs after.

The tapping noise is either piston slap or I'm hearing something in the exhuast, but you have to try to hear it, so - most likely just normal motor sounds.

When I eventually get the nozzle out of the 3hp carb, I'll be keen to test it out. Not sure how to get the nozzle out without breaking it and drilling it, maybe I'll put it in my freezer for a while ... lol

got that nozzle out. the end is buggered, but it could probably still be used, but I got a replacement I'll use. another piece for the odd parts bin. I heated it up good and applied solvent and penetrating oil, let it sit, heated it up again an hour or so later and applied more penetrating oil, and then worked it back and forth with vice grips, just hard enough so the grips wouldn't slip. took about 5 minutes of just applying back and forth twisting force and then it started to move a hair and a couple minutes later it was out. I probably could have just spun it in a vice, but I really didn't want to snap it off, or strip the threads in the carb body. so, that carb just needs to finished getting cleaned and put back on and we'll see how this motor runs with the correct carb. I was going to run it again tomorrow to go fishing, but I have another trolling motor on the boat already to go, so - I'll take my time and do it correctly, reminding myself I bungled the carb trying to do things too hurried in the first place ...

ran this motor good. probably 4 -6 hours of mixed running over 2 or 3 days. Seems to run great. Think at some RPMs I'm rining the flywheel like a bell. I'll probably mess around with it Wednesday, next time I run it. Think I'll just put tape on the flywheel to see if it changes the harmonics. I kind of figure I'm just ringing it at certain RPM ranges, and that seems like a decent way to try to confirm the theory before I pull the flywheel and try to align things again.

I ran a 3hp Evinrude last week, and in a similar throttle position, I got the same harmonic dog ear high pitch chirping, but it was much harder to recognize, not as loud, but same exact sound. Maybe I need to do a bit of a fix on that one too soon.

been runing this motor trolling. haven't had the flywheel off again to check and reset the coil position and to look in at the ignition to see if I have a wear spot from rubbing. runs good starts easy, high speed run strong for extended periods, I just avoid the mid range where it chirps a bit, which I'm convinced you're right it is coils rubbing. I heard my Evinrude 68, make the same noise, not as pronounced, but the same high pitched tone at a similar RPM, chirp. For trolling I think I need a hotter plug, doesn't like to troll down below 2.5 mph. It will, but it starts to miss after a bit, and sounds like it might stall out. I think it is the standard Champion J6C plug I'm running. Max speed on my GPS spedometer is about 5mph, thought it might hit 6, but I don't want to troll that fast anyway. Just backed off full throttle, it settles into about 4 mph, which is a fast troll, but I've had most of my success, up at 3 or 4 mph, and not down at 1.8 -2.5, which seems to be more common, but I learned it by trial and error, and never used a speedometer before to really know how fast I'm trolling.

ran this at least 10-15 hours trolling over the last couple weeks.

tried to run this motor yesterday, and it started first pull after sitting for a week, and it started fine like normal, but when I tried to start pushing the choke in it did not rev up, and after about 10 seconds it stalled. It seemed flooded, so - I ended up pulling the plugs and disconnecting the tank, and just cranking it out, a lot, and then letting it sit for a half hour, and put new plugs in it and it started for about 3 seconds and stalled. The new plugs did not seem wet, and upon closer inspection, the carb was readily leaking gas from the top right little hole, every time I pulled the engine over. Strange, the same motor went from severely flooded to no gas. All I can think of is stuck or sticking float assembly. If I squeezed the bulb, gas would come out the same hole, so - what is that float stuck and needle not seating at all? I tried tapping it a bunch with my socket, to no avail. It still confuses me that at first it was just flooded, wet plugs, gas shooting out the cylinders when I pulled it over, like the crank was just filled with gas. Then after I let it sit for a long while, the new plugs barely smelled of gas at all, and gas was coming out the front of the carb, and apparently not going into the crank, but if the bowl is full, it would have to go into the crank, what would stop it?

Cork float is soaking up gasoline. Buy NEW float . Been there. Some dissolved varnish may be on parts. But mine worked perfectly when replaced.

I ran this motor a good bit last year. I don't know - maybe 30-50 hours of service. Trolling, just boat rides, etc. Regular use. It seemed to run good, I found a bugger in the carb bowl, and that solve the why is the float sticking question. A piece of the gasket had pinched, and sort of became like a little whisker, that the float was catching on. I pulled it off, put the bowl back on, same gasket, about 10 hours on this motor from fishign this spring.

This motor was making a high pitch noise at some RPMs, mid throttle. I pulled the flywheel and it was definitely was rubbing on one of the coils. I couldn't really figure out why, so - just messing around, I took the flyweel off another motor, and it did not seem to contact, or contact as much, so - I did a run test. I cleaned and reset the points while I was in there. I also switched to J6C plugs, I had J4C in it. and ran 93 octane gas, which should make no difference, but it was in the can from testing another motor, where maybe it did matter.

Idles better. Seems like I was able to run it at better trolling speeds and not have it start to caugh and drop a cylinder going too slow. It should be able to do that, it will idle down slow enough you can basically put your finger on the flywheel it is going so slow, but it will only do that for a couple minutes, and then start to slowly drop a cylinder and then stall. But, it woul do this same thing at like a 2.5 mph trolling speed, and RPMs way above an idle. Seemed not to do that today, and it would troll way down fine and run smooth, just guessing, but down to 1.5 mph, slower than I would want to troll for the most part anyway.

It still squealed a bit, but in a much narrower range of the throttle. It is a bad sound, but at least I know what it is. I could go back under the flywheel, but - hey, for now it runs better, squeals less, and should just run good for a long time and I'll live with the little bit of squeal for a second going on and off throttle.

It is a bit loud, but I've heard others of this exact same motor make that same noise over the years, and just never knew what it was. It is a little more noticable coming off throttle, but it definitely rubs going both ways and rings the flyweel.

line up the coils !!! no reason to rub on te FW...

I lined them up, the coil seems to rub the magnet right in the fat middle part of the coil, there is a flat square thing on the rounded outer edge, it rubs there. I have no idea what else to try to align in there, other than switching the coils side to side. It is in the alignment marks and I've done it 2 or 3 times to go back and try to get that coil to set back a hair farther, and it hasn't worked.

I tested the compression on this today. 107 top, 102 bottom 5/27/2025

Use a file on the middle part of the laminations to get the clearance you need.-----

racerone said:

Use a file on the middle part of the laminations to get the clearance you need.-----

Click to expand...

Just to make sure I don't do anything too dumb. You mean on the coil, yes? I can just file that down? It already looks like it has chewed a bit of it out, so I have no doubt where it is rubbing. How thick is the housing, I guess if I made a hole I could seal it with RTV or something.

Just as a note, it is also obvious on the flywheel where I assume the magnet is, clear marks from rubbing. I thought swapping the flywheels made the ringing better, but after a few trips, not really, same as before.

Repair / modify as needed.----You could also drill mounting holes 1/32" bigger.-----But remember that a factory tool ( I have it ) is used to set this clearance.----The correct clearance between magnets and heels of the coil gives you the strongest spark.-----Weak spark is a major cause of the " hard to start " condition.

See post #7
your fingernail must not snag going up or down at the coil juncture with the mag plate . if needed use a screwdriver to pry the coil face backwards to line it up....or has suggested slightly enlarge the bolt hole (S) enough to recess the coil from the edge. use star washers to lock the coils in place