'96 Challenger 787 Starter Issue

[wernerml]

Sorry to start another thread about starter problems but I'm stumped.

Rebuilt my 787 last year. Ran it for 5~6 hours of break in ( had a couple of nice days in October) then put it away for the winter. Brought the new battery inside for the winter and put it on a trickle charger once a month for a day or so.

This spring it wouldn't start. Starter engages but engine won't spin. Removed the plugs and sprayed oil all over the place. Spun the engine with the starter quite a bit and got it all cleaned up. Put pinchers on the oil lines to the rotary shaft to keep the oil from coming back while I'm trouble shooting.

Engine continues to crank strong when plugs are out. Sometimes it will crank with the plugs in (seems to be just after topping up the charge on the battery??) Most often it won't. Sometimes for seemingly no reason it will crank when I try, Bendix is working fine. Had the head off, pistons and cylinders look fine very little oil residue on the top end. I have used a little starter fluid and have gotten it to chug and spit a bit.

Took the starter off and opened it up. Cleaned out the carbon and cleaned between the copper pads of the commutator brushes looked ok. Put it back together. Maybe is slightly better but still often won't crank.

Today cleaned the ends of all the cables for starter power. Checked they are tight. Tried to smash the crimps a bit. Put some "No-Corrode" on them and put it all back together. Same crap.

Swapped battery with the one from my Wrangler. Same issue. Got out my fancy volt meter. Measuring my Jeep battery I get 12.5V idle and 9.8V while attempting to crank. Bendix engaged, engine not turning. Using my Marine battery (675 CA) 13.0V and 10.2V while attempting to crank.

I think my next step is to replace all the battery / Starter cables. I have tried to measure voltage at the starter lug and I am getting numbers like 7.5V. I have ruled out the starter solenoid.

If the cables don't solve the problem I guess I am in the market for a new starter. Starting to tick me off since it is now Mid July and no boating yet this year.

 

[POPPS]

I would start by load testing the battery and go from there.

 

[brownie545]

If your battery load tests ok I would double check all grounds, 9.8v loaded seems a bit low.

If wiring checks out just rebuild the starter. Brush kit only costs 30-40 bucks and is pretty easy to do. I would not recommend buying an aftermarket starter.

 

[wernerml]

Battery Load tested good. Not surprising since it is less than a year old and only was in the boat a couple of weeks before it went to the basement for the winter.

I had checked all my connection points on the high current wiring. Today I purchased new 4Ga wire and crimp terminals to replace all the high current wires. Hope to get that put together in the next two days.

To be continued...

 

[wayneh]

My money is on the starter having partially failed. A bad winding will do it. If I'm right, you should be able to detect an amperage draw below specifications. The motor can't do the work it needs to because it's not getting enough electrical energy. I suppose a winding might fail in a way that maintains current flow but fails to convert that energy to mechanical energy.

Anyway, I wouldn't be so resistant to a new starter. I think you'll save yourself a lot of heartache to just get a new one.

 

[wernerml]

Well after a long weekend away doing other things, I got my battery/starter cables rebuilt and reinstalled. It faked me out by cranking three attempts in a row, then stopped. :-(

Removed starter again. Reading ~0.4/0.5 ohms between all commutator segments, and a random first segment. Have the name of a local electrical motor guy to take it to for a test. Another couple of days...

 

[wernerml]

Continued... Visual inspection of windings and commutator show no signs of excess heat or wear.