My uncles motor needs help.

[ForkliftJeff]

My uncle always used to let me use his boat and motor whenever I went camping at the lake. I've had my own gear for a couple years now but just got to thinking. That motor is a piece-o-crap and needs an attitude adjustment. From what I remember, it starts fairly ok. But the problem that I would like to figure out is this: Lets say you've just noticed a giant evil rain cloud comin straight for ya. You reel in your gear and gun it towards camp. Everything is cool, your cruisin at full speed, the cloud is behind you, then wham! It loses all power except for a struggling troll speed, the cloud catches up to you, gets you soaking wet, and when your lining yourself up with the dock, WHAMO, back into high speed. And yes that is a true story. This motor does that all the time. You could be trolling (usually too fast cause somethin aint right) and then it goes to super slow mode, sweet for trolling so you adjust throttle speed to get trolling good and after a while, boom, back into high speed mode. Bummer. Just wondering if this is a simple fix and adjustment I could do at the dock or if it needs some serious TLC. I'm hopin for a simple fix because the motor is at the lake which is 4 hours away. I just want to be able to fix it next time i'm there. It'll give me something to do until the fish start biting.

The motor is a Johnson 6HP (i think). Not sure how old but I'm guessing 70's or early 80's. Here's the only pics I have that show the motor.

Thanks for any help.

 

[Defiant]

You have either a coil breaking down when it gets hot and shutting off spark to 1 cylinder until it cool's off or the or fuel pump is not keeping up or maybe a clogged vent .Check for spark at both cylinder's when it starts acting up and also try pumping the bulb to check for fuel problem

 

[ForkliftJeff]

Awesome, never thought of 1 cyl shutting down. I'll check it for spark next time I'm up there. I think I've tried pumping the fuel bulb with no change in performance. Any ideas on the year in case it does need a coil or something?

 

[Defiant]

Not sure on year need the model number to be sure here is a guide when you get the model number


https://www.brokeboats.com/omcid.html


And here is a parts break down when you find out the year

https://shop2.evinrude.com/ext/index.aspx?s1=d007b7ab985337bef4b0f681fe6ffb9f

 

[Rat]

I would also take a carb rebuild kit with me; its either not getting fuel or not getting spark.

I would rebuild the carb and fuel pump and install new hoses; you can proly do this for less than $50, and it proly needs it anyway just based on the year of the motor.

As Defiant said, check for spark. Of course you will need to run it until it starts acting up and THEN check for spark, don't check for it while it is sitting in a bucket of water idling fine It does sound like you are loosing one cylinder tho, rebuilding the carb and fuel pump and replacing the lines will give that little motor new life!

 

[ForkliftJeff]

Good stuff guys, thanks. Sounds like I'll most likely just troubleshoot it up at the lake and then bring it home to do the work so I can give it a good once over at my shop. I hate working on stuff without the right tools.