35hp outboard cranks slow

[sgoerne]

i have a 1976-1978 35 hp chrysler outboard that cranks slow. i pulled the plugs out and the motor spins over fine. the cylinders each have 100lbs of compression and i have bypassed all wiring to the starter. tested the starter on the bench tester and it pulls 46 amps at 10.45 volts. also checked amp draw when mounted on engine and it pulls 100 amps. seams to me like the starter just does not have enough torq to turn it over but ive never ran into this before. any suggestions would help.

 

[john from md]

Re: 35hp outboard cranks slow

Start from the beginning.

How old is your battery? Have you had it load tested recently?
Check the cables for corrosion under the insulation if they are a few years old. Also, clean the oxidation from the ground contact points for the negative cable and starter.

10.5 volts is the maximum drop you should see with the starter cranking an engine. If you get that much of a drop free turning on a bench, it is time for a new starter as your field wires are shorted.

When the fields get hot on older starters, the insulation breaks down but not enough to stop completely. This is what is probably your problem. If it is an old one, it is time to get a new one.

John

 

[sgoerne]

Re: 35hp outboard cranks slow

thanks for the info. i took the starter to a local rebuilder and he said the brushes were shot but everything else looked good except for some rust from it siting for so long. 20 bucks is all it cost me. helped alot think i fixed the problem. thanks alot tho

 

[john from md]

Re: 35hp outboard cranks slow

Good for you.

John