Starter issue J10RELEUS 9.9 Johnson

[w2much]

Motor runs and starts fine with recoil starter. Electric starter is the issue here. I cleaned to shinny all solonoid and starter connections. I am not using a key, instead I am jumping the starter with cables to the starter. Battery is brand new and fully charged.
When I jump the starter it cranks well and engine will start. But........... if the engine is cold and a longer cranking time is needed the starter slows down and performs as if the battery is dead or dying. It will start the motor, the bendix will engage but I am concerned that one day soon it will not get a long enough crank to start the motor. Curious as to what might be causing the starter to perform in this manner.

 

[jakedaawg]

Starter maybe weak. As windings heat up they open. Easy enough to disassemble and check brushes and comutator.

Also load test battery, new means little. What size CCA is it?

Wires may also have internal corrosion.

 

[racerone]

These starters use a ground that is cheaply riveted internally.----------This may or may not be your issue.--------It is a simple inspection and cost no money.--------------Last one I did was a simple fix.----Drilled a hole for a small nut and bolt for a permanent fix !!

 

[Crosbyman]

any electrical junction point (internal or external) can heat up as current flows and cause the resistance to increase and... drop the voltage to the starter(and current) (you can always check hot points with a finger)

​you can measure the starter voltage while it cranks and it drop much you have an issue to solve (a battery swap is the easiest ) . Redo/polish all connections

if that fails..... the starter ... as sugested... may be going out to lunch. ....

​ btw a new battery can be a bad battery ... excrements do happen

 

[Crosbyman]

see comment on bad... good battery....pasted from another post

All of you were correct that it was the battery! It wasn't old but for whatever reason it was defective so today I returned it to ******* and they gave me 100% credit on it and I paid $22 to upgrade to one with more reserve power. BTW, I always recharge both batteries after each trip and had noticed the starter battery seemed to take too long to recharge which probably should have tipped me off. THANKS FOR YOUR WISE ADVICE! Steve ​

 

[w2much]

OK , I am certain the battery, cables and soloniod are good. I took the starter apart and cleaned it. It really seemed (appearance) to be in good shape as were the brushes.
I reassembled it and no difference. It cranks as if it were using the last bit of juice from the battery. Starts off well then slower and slower.
Not to be afraid to ask what may be a dumb question but...............are both brushes positive or is one negative.?
Racerone mentions a cheaply rivited ground is that the other brush which I should bolt through the bottom body of the starter?

 

[w2much]

O K one is pos one is neg. Got it.
Took another shot at it.
Looked at it with a more discerning eye and saw that where the brushes contacted the armature was worn almost concave instead of a flat surface. I switched the armature with another starter from the dead zone, stretched the springs for the brushes a little bit and reassembled. Three was the charm. Starter now cranks strong and long. Sounds and operates as new.