Rubbing noise

[Don Hansen]

I was using my 1970 4 hp to come up a creek when it slowed down to 3/4 speed. Maybe 30 seconds later it started to squeak and then make a heavy rubbing sound like someone using a coarse file on metal. Of course I shut it off. I was sure a coil had come loose.

There's a guy in my area who's noted for being good on older motors. He checked everything. The water pump, the coils, the gear box, and ran it for a half hour. He could not repeat the symptoms. He also said that the motor didn't appear to have over-heated.

I probably won't be able to take the motor out on a lake before my trip to Canada but I am going to run it in a barrel just to make sure. I'm just confused as to how the motor could make that rubbing sound and then have it go away like it never happened.

Has anyone here seen those symptoms?

DLH

 

[Will Bark]

Re: Rubbing noise

Check your flywheel nut to make sure it is tight.

 

[Rick.]

Re: Rubbing noise

When you come to Canada you can use my 71 if you break down LOL. I'm thinking you overheated but who really knows. Could be your inlet was blocked by weed, mud, whatever. Do you know if the fellow did a compression check? If your impeller is more than a couple of years old it would be good to get it replaced no matter how it looks. The rubber, over time, can set and not perform properly at speed. At the very least you should give it another run before your trip. Best of luck and good fishing on your visit. Rick.

 

[Don Hansen]

Re: Rubbing noise

Just to let the readers know why, I'm capable of working on the motor myself, but I've been fighting a health issue the last couple of years. At times I'm so uncomfortable that I don't trust myself working on something that requires a clear head. That's why I took it to a mechanic.

One of the first things I checked to see if the flywheel was loose or that the upper crank bearing was shot and it had play in it.

It may have overheated. Do the symptoms sound like that? My motor is a long shaft weedless that sits up on the shoulder of my 1980 Mirrocraft Deep Fisherman. Because the prop is still way too deep in the water and to get the prop facing directly back, I built an extension to the factory tilt. I did notice that I had forgot to use it.

I will do a compression check on it. Do I squirt oil in each cylinder or not and what compression would be acceptable.

DLH

 

[Rick.]

Re: Rubbing noise

Unless it's been sitting a long while I don't think adding oil is necessary. Compression numbers are a bit speculative. Remove both plugs and ground the wires. I'm going to say anything above 75 PSI and the two cylinders within 10% of each other. Others may not agree. Let us know. Rick.

 

[Don Hansen]

Re: Rubbing noise

If I check the compression and it appears to be OK, did I luck out. Because the mechanic didn't mention anything bad I'm hoping I did.

A question of curiosity. Since I can?t buy a new 2 cyl weedless 4hp anymore are there short blocks available? If not, what about parts to overhaul the power head?

DLH

 

[Rick.]

Re: Rubbing noise

Don. I'm thinking your engine will be fine. A compression check after an overheat is just a good thing to do. The fact that your mechanic could find no obvious rub marks and what you experienced, leads me to think you overheated it. At best your readings will be fine, at worst you would need to rebuilt the motor, but more than likely it will be fine and if not probably the corrective repair would only require a new head gasket. I'm sorry if my comments have caused you to worry needlessly. Do the compression test and let us know the readings. Best of luck. Rick.

 

[Don Hansen]

Re: Rubbing noise

No! No! Your comments didn't bother me, I was just trying to find out what to expect and what would be the best route to take. I don't normally use the 4 hp here in Wisconsin, except as a backup, because we can't power troll. Because I do a lot of trolling in Canada, I put twice as many hours on the 4 hp as my 35 hp. Last year when the 4 hp quit I started trolling with the 35 hp. Almost had a 11 mile row because I didn't check to see how much more gas the 35 hp used over the 4 hp.

I forgot to mention another reason I want to keep the 4 hp. It hooks up to a remote tank. I just switch the fuel line from the 35 hp to the 4 hp and visa versa.

DLH

 

[Rick.]

Re: Rubbing noise

I hear you. I'm amazed how long we can troll my 4hp on a gallon of gas. We determined once we were using on average 1 liter per hour. Last time out my 40hp would not fire so the 4 got us back to the dock. Rick.

 

[Don Hansen]

Re: Rubbing noise

And that too. It's common, where I go in Canada, not to see a boat all day. When the camp owner said, during my first trip in 1973, if you break down don't expect me to come looking for you until the next day. I said hello 4 hp.

DLH