'72 100hp Johnson Hydro Electric

[jhetrick55]

I have the motor from the post's title. I've been noticing if I pull a tuber, or anything else, even at slower speeds, the motor runs rough for a short time and sometimes pops out of gear, but this is rare. I know strong battery connection is essential for these engines, and the battery cables have been replaced, and they needed it! I've wondered if the clutch dog could possibly be bad, but I am not sure where to go from there. What other signs are there of a bad clutch dog? The boat does run great anytime I'm not pulling a tube or something.

Does anyone know what else I could check if not clutch dog?

 

[racerone]

There is no battery voltage to the shift system when in forward gear.-----It is spring loaded to go into forward gear.-----If the bore of the shift piston is dirty / contaminated the clutch dog may not move properly to fully engage with forward gear.----Easy fix on my work bench.

 

[jhetrick55]

So what would cause the engine to run rough after pulling a tuber?

 

[F_R]

Not enough information. I would be totally surprised if it has a bad clutch dog. Does it shift FNR ok?

 

[racerone]

Trouble shooting needs to be done.-----Possibly running too hot.-----Spark leaking from plug wires.------Air leaks in fuel hose.----Weak fuel pump.-----Poor compression ----Weak spark ----On a few other things to be checked.

 

[oldboat1]

Have you drained/refilled the gearcase?

 

[jhetrick55]

F_R, it does shift FNR just fine, unless it has popped out of gear, obviously.

Racerone, i do have a concern about air leaks in the fuel hose. I am 100% confident I need to replace the old copper tube with newer fuel line. I know compression and spark are good, and i am pretty sure the fuel pump is good to, all that based on things I had done within the last year. I know I've got good flow of water to cool the engine as well. I'm going to give the fuel line replacement a try because i've suspected that needs done anyways.

Oldboat1 - I did that just a week ago. I wanna check to make sure it hasn't taken on water though. I am wondering about replacing lower unit seals.

Thanks for the input!

 

[jhetrick55]

Racerone... I may have spoken too soon on replacing the copper fuel line. The more look, these old glastron copper fuel lines hold up real well and are grounded nicely. I know the copper line is not leaking, but what may be leaking is where it connects to the rubber fuel line in the bilge area and then runs to the engine. The primer bulb never fills up and my thought is that there is a leak somewhere in the rubber fuel line/primer bulb which needs securing.