How much damage did I do?

[camax8]

Spent the whole summer restoring my 16 footer.<br />New floor,new vinyl, new seats yada yada yada! Did nothing to motor. 1986 70hp yamaha.<br />Took it for a spin ran great for a couple hrs.<br />On the way in 1/2 throttle bam! Shut off wouldn't<br />start. Motor would not turn over.I don't have a temp gauge on the boat but<br />when It shut down it wasn't hot at all. <br /> Towed back to the ramp disgusted. I tried to crank by hand felt like motor seized. Pulled plugs they were light brown one was wet two others dry as a bone.<br />The oil injection doesn't seem to be working. The<br />lines had no oil in them and I pulled the oil pump and checked it by spinning it w/drill while connected to oil resevoir. It did not pump.<br />I put everything back together spun the motor by hand using the biggest wrench I got and ran a little pre/mixed. It turned over and ran but I shut her down fearing the worst. I'm no expert<br />know enough to be dangerous. I'd like to work on the motor myself any suggestions? Check compression, start it up with pre/mix and see if<br />blows?

 

[Kinglg]

Re: How much damage did I do?

Your probably not going to hurt it any more than you already have by starting it with premix. I would mix it a little rich on the oil side though. Maybe pull the plugs and lube the cylinders first. Probably <br />will smoke like a stack for a while. good luck.

 

[jim dozier]

Re: How much damage did I do?

If you can turn it over, before you run it again do a compression check. Post the numbers here. the values for each cylinder should be within 10-15% of each other. If one or more cylinders is low, I would pull the head (not very hard if the bolts come out) and have a look see at the pistons and cylinder walls. Then you'll know.

 

[camax8]

Re: How much damage did I do?

I'm optimistic that there is no major damage.<br />It did run great for two hours. It might<br />have been getting some oil. I'll look at the compression and post the numbers. I'm hoping<br />that I won't need to get into the motor. Like<br />I said I know enough to be dangerous Thanks for the quick replies!