1989 Force 85 No start, hard to turn over with plugs

[pgallipoli]

I have a 1989 Force 85 motor with no lower unit. It turns freely, quietly, and fast when no spark plugs are installed, but when I install all 3 plugs it becomes hard to turn by hand, and the starter gets "stuck" trying to turn it. No better when I jump the starter with jumper cables directly from ground connection to red nut on starter. I tried a 2nd used starter, then tried a brand new starter; not much better.

If I take out 2 of the 3 plugs, the starter turns fine and I can hear it fire on one cylinder. Put in any 2 plugs or all 3 in any cylinder and you have a very hard to turn motor. I have a 1985 Force 85 and I have no problem turning that motor with either starter and I can every rope start it. This one seems to have some problem when the plugs are installed.

No signs of water or anything sticking. Today I took out plugs and sprayed about 2 oz of myster oil into each cylinder, let it soak, then tried (no better), then tilted the motor (carb side down), and sprayed more mystery oil as I turned the flywheel slowly; hoping to loosen it up.

It turns great with no plugs; easy to turn with palm of hand, like 2 rotations per second, no noise, but install two plugs and this thing is very hard to turn. I even tried to turn the plugs about half way in (in case they were making contact), no better.

Any ideas?

I guess I could pull the head and look for any carbon or other signs of wear.
I assume it's probably a few burnt or bad bearings maybe the crank bearings?

The motor 1989 Force 85 model 856X9B

Thanks in advance for any help/ideas.

-Rino-

 

[jerryjerry05]

Re: 1989 Force 85 No start, hard to turn over with plugs

Do a compression test.The results should be all about the same.Any big difference will make it hard to turn over.
It's possible the starter is weak too.Do the test first then the starter.J

 

[pgallipoli]

it's a long time ago, but for those with the same problem; here is the solution.

Starter was too weak. The starter spun up on a battery, but maybe some windings were shorted or loose, I got a new starter and all was well.
Also, I noticed using jumper cables and low guage wire was causing me some starting power; switched to 4 guage new cables right on the battery and it purred like a kitten.

It turns out the other motor I had that was able to be pull started had low compression. Both are gone now, but now we have the mystery solved after 7 years!

 

[jerryjerry05]

Finally,YEA!!
It's amazing what a bad wire or bad starter can do.