1977 Evinrude 70hp Problems

[1977Evinrude]

I had my boat on the lake last weekend I was running it at 3/4ths throttle and all of a sudden the rpms started dropping until the motor stopped. I tried starting the motor, and the started engaged, but the flywheel was stuck. I couldn't manually turn the flywheel. I let it sit for a little while and I was able to manually turn the flywheel and the motor started again. I was able to put the boat into drive, but after about 100 yards it did the same thing and died again. I pulled the boat out of the water and pulled the spark plugs to see if there was water in the cylinders. It looked like there could possibly have been a little on the threads so I put a little oil in the cylinders and the motor turned over and started. Anyone have similiar problems or have any idea what could be the issue?

 

[WillyBWright]

Re: 1977 Evinrude 70hp Problems

That sounds like siezure from an overheat. Once the block cools down, things start moving again. It could also be lack of lubrication in both the powerhead and gearcase. Are you putting oil in your gas and how much? How is your gearlube? None of those situations bode well. Your motor might have suffered serious damage. Let's hope not. Hope for the best but expect the worst.

 

[1977Evinrude]

Re: 1977 Evinrude 70hp Problems

I run the mix at 50:1, and I had replaced the gearlube in the lower unit which was fine without any shavings, or signs of water.

 

[1977Evinrude]

Re: 1977 Evinrude 70hp Problems

I had the boat out 4 times this year and the first 3 times I didn't have any issues.

 

[F_R]

Re: 1977 Evinrude 70hp Problems

Is the paint discolored or burnt on the powerhead? If so, the motor was ran hot to the point of siezure. NOT good at all....

 

[1977Evinrude]

Re: 1977 Evinrude 70hp Problems

The motor wasn't running hot. I made sure that wasn't the case right away.

 

[tashasdaddy]

Re: 1977 Evinrude 70hp Problems

will it start now? try running on muffs, paying close attention to the pee stream and the temperature. have you done a compression check? do not rev over 1500 rpms on muffs. you didn't answer the paint question. it could have been hot before you got it, and the problems are now surfacing.

 

[1977Evinrude]

Re: 1977 Evinrude 70hp Problems

It does start now on muffs. As soon as I get a chance I will get out to look if the paint has burned at all. I will also do a compression check.

 

[F_R]

Re: 1977 Evinrude 70hp Problems

If it wasn't hot, then you have a bearing siezing up (Bad!), but not too likely because they don't usually unsieze. Or maybe something external is locking up, such a screw came loose under the flywheel. That would be the best case scenario. Let's hope for that one.