engine start

[joe]

since i took possession of march hare,i've had a problem with starting the engine when i'm ready to return to port. in the slip, the engine starts readily on the start battery. when i'm ready to return to the slip,the start battery will hardly turn over the engine, and certainly not enough to start the motor. i've had to turn the selector to the "all" position. the motor turns slowly but has then started. thinking it was a bad battery i bought a new one, but i have the same problem. the new battery checked ok across the poles before i hooked it up but did not provide the zip to start on the second try. any suggestions. tx joe

[Jeff_McKinney]

Joe,

A couple of questions before the experts jump in:

1. What type & capacity is the start battery?
2. How are you currently charging it when not running the engine?
3. What else are you running that might suck the start battery flat?

I'm sure there are others with much more knowlwdge, but this is a start.

Good luck.

[Ron Hill]

Joe : For Jeff's sake, your boat originally came with 2 group 24 batteries that over the years MAY have been upgraded to 2 group 27s or even 30s.  That's what will fit in the molded sections of your battery compartment.  Jeff had 2 4 Ds with 400+ amp hrs!!!  A group 24 alone should be able to start your smaller engine - Jeff had a a 35hp engine which is quite different. 

Your problem is that you're connections from the battery's, thru the Perko switch and to the starter solenoid aren't the best.  What I'd do is solder all of those battery connections (might need a small torch and rosin solder).  In the meantime when you want to start and the engine is warm, lift the decompression lever and then put it down and hit the glow plugs and starter.  The decompression lever will allow ambient air in the cylinders and allows the starter to turn over easier. THE GOOD SIDE IS THAT YOU PROBABLY HAVE GREAT COMPRESSION, but need some better connections.   

[Craig Illman]

Ron, et. al. -  You don't think there's a chance his starter is suspect, working fine when cold, but having trouble if it gets warm? I agree that addressing his cable terminations is a necessary, inexpensive first step.

Craig

[Jeff Kaplan]

joe, on my '86 with m25, 2 group29 batt., at the end of the sail, i must hold the glo button in for 10-15 seconds to re-start. i always keep the batt. select switch on" all or both"...jeff kaplan

[Footloose]

Joe

Ron is correct!  It is the connectors on the ends of the cables that are the problem.  I suspect that even when it is cold it is turning over more slowly that it could.  Cut off all of the connectors and then solder and crimp on new ones.  Use shrink tubing where the connector meets the insulation to keep out moisture and you be good for years to come.  The connectors in the battery box are probally the most visibly corroded,but be sure to replace the ones on the Perko switch at the nav station and two at the engine.

Besides having hot air in the engine, electrical resistance does go up when items get warm.  A small amount of resistance at high amperage draws (like when you hit the starter) result in major power losses.  One ohm is enough so that you probally won't start.  It would be a loss of over 4 horse power which probally more than your starter puts out to begin with.

Good luck.  I had a similar problem last year.  This solved it.  If you haven't upgraded your wiring harness and installed a solenoid for the glow plugs do that also.

Dave

[Stu Jackson]

...and don't forget the fuse holder, wiring and spade connector (from the ignition switch).

[Ron Hill]

Guys : If the engine starts cold, but won't start when warm (and the starter turns over slowly) you've got a bad connection!  If the starter won't turn over at all, then look at the fuse holder (as Stu mentioned), flat spot on the starter? or a bad starter solenoid etc. 
Joe, I guessed that the starter is turning over, but the engine won't start ??  If Joe had said that all he heard was clicking (beside the electric fuel pump) I would have said it's the solenoid.

When you ask a question, please give ALL of the symptoms, so we can give the best answer with out having to guess.     

[Steve Hansen]

Joe,
You described the problem I had to the letter. I put in new terminals, crimped, soldered and shrink wrap. I changed to 2 gauge wire (I had a length available that the PO left behind)  and also installed a dedicated start battery ala Jim Moe. Engine starts right up, no problem. Here is a picture of the corroded terminal after I removed the electricians tape..
Steve

[joe]

to all; i really appreciate your help. i will implement your suggestions. it will be about 2 weeks before i will be back at the boat to do so. i will then report on the results. thanks again. joe

[joe]

i replaced the wires and connectors to the baterry posts(both batteries) and that has cured my problem. the engine now starts quickly at all times.for those who might be interested, you can buy a spray at any auto parts store to coat the terminals and exposed wires which helps retard further corrosion. thanks for your help in exorcising the devil in the system. joe