1981 Chrysler 75 HP Outboard Starter Issue

Hello. This is my first post and I am new to Chrysler outboards. Helping a friend with the subject motor. He bought it for $75 at an auction. I got the ignition and fuel working. Compression is good.

The starter on it looks new but I don't know the source. It could be a cheap ebay unit.

With the spark plugs out the engine cranks over easily. With the plugs in the engine turns over very, very slowly. The battery is good.12.4 volts. When I hit the starter, the voltage drops to 6.5 volts when it is cranking slowly. After about 10 seconds of attempting to crank, the bottom of the starter is very hot to the touch. I have cleaned all of the power connections and grounds.

I want to assume the starter is bad but I have one problem. I have tried to start it by wrapping a rope around the flywheel and pulling. No dice. It is impossible to pull start. I'm 6'1", 245 pounds and I nearly pulled my arm off. Has anyone ever tried to pull start one of these. The only difference between easy to turn over and impossible to turn over is the installation of the spark plugs creating the additional load of compression.

One possibility that I have yet to diagnose are the battery cables themselves. They are very old and very long. For some reason, they are run all the way up to under the steering wheel so they are about 16 feet long. I plans on getting some new ones that are about 6 feet long.

In the mean time, do you guys thing it is the starter and has anyone had any success pull starting a 75 hp with a rope.

thank you.

These 3 cyl. motors can be real hard to turn if the compression is low on 1 or more cyl.

The starters easy to clean.
Check the cables for twists or bad spots and make sure the end is clean.

Do a compression test.
The results should be within 5-10# of each other.
The actual readings can vary with the gauge or the person doing the test.

Remove all the plugs, install tester, turn over until the gauge stops going up.
Post the results.

Jerryjerry05 said:

These 3 cyl. motors can be real hard to turn if the compression is low on 1 or more cyl.

The starters easy to clean.
Check the cables for twists or bad spots and make sure the end is clean.

Do a compression test.
The results should be within 5-10# of each other.
The actual readings can vary with the gauge or the person doing the test.

Remove all the plugs, install tester, turn over until the gauge stops going up.
Post the results.

Click to expand...

Compression was dead on at 80 psi for all three cylinder but it cranked over very slowly so the number would be higher if it turned over at the correct speed. All plugs were removed for the test. Even putting in one plug or the compression tester is enough to make the engine turn over slowly.

If the comp was 80 on all 3 then the problem is the starter or the battery????
A battery can read 12v and still be bad.
It could have a dead cell???

Harbor Freight load tester. Under 25$

Comp with a good gauge should be closer to 145/150#

But since all 3 were the same I'd think your ok.

The battery is good. Load tested by the BMW dealer. I am replacing the 20 foot battery cables (there were clamp-type splices in the positive side) with new copper cables that are 6 feet long. If that doesn't work I'm doing the starter.

I'll post my results.

the motor must turn 350 rpm to reliably start...to me 6.5 volts under load is too low..what do you read on the battery post when trying to start?get the reading from the post itself and not the lug on the wire..