Join Date: Jun 2014
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Re: Volvo Penta MD6b Cold Start System
Well the mystery deepens- the starter began to crank slowly and then would not turn the engine any more. I started tracing wires and felt that I had a good 12V to the solenoid so i was thinking the supply to the starter motor itself was not good- Just to check I removed the starter and took it to a shop that could test it - where it was given a clean bill of health.
I was able to determine that the crimped connection on the 12V to the solenoid was not secure. It would read continuity but with motor movement and vibration it must be intermittent. I pulled it off and soldered it. I also put the original ( now rebuilt) starter on the boat ( rebuilt by Buckeye Auto Electric in Painesville, Ohio - highly recommend for old vintage stuff like this MD6B) .
I turned the key and the motor started immediately, without hesitation. Cranked less than 2 seconds. This was after not running for a week. I started it and stopped it 10 times yesterday and motored around the river and harbor here for 4 hours, and it ran beautifully- idled down , shifted gears, up to 1500 rpm, 700 rpm idle etc. etc.. Too bad it was too windy to do any sailing. Good news was we explored up river where I had never been before because I assumed it was too shallow but we had 12-13 feet of depth all the way to an old railroad bridge and found a marina full of sailboats - !
I know the engine is old and tired- but I am at a loss as to why this wire connection would prevent it from starting except it is possible it simply turned the engine too slowly to fire.
I also changed out the oil ( still cleaning it up from the leaky lift pump diaphragm)-and added some goop from Rislone that is intended to help the rings seal .Probably only going to make me feel better but it may help a little .