M25 trouble starting

[sdaly66]

Folks,

Had a mysterious happening yesterday, and need help/advice before I spend a ton of dough having a mechanic look at my engine.

Yesterday motoring out of St. Michael's, had the engine running for a good two hours.  Made the turn into the Eastern Bay and cut the motor, sails up.

Motor had run fine and run cool the whole time - no strange noises or anything of the like.

Tried to restart the motor after 15 mins and it would not fire.  Plenty of electrical power, fuel pump clicking, glow plug hot, she just turned slowly and wouldn't fire.

45 mins later, she started up just fine.  I mean fired RIGHT UP.

Got back to the marina motor sailing - wasn't gonna take a chance and turn her off again.

Tried to restart her at the marina with the same effect as before.

I'll bet dollars to donuts that tomorrow, she'll start up just fine.

Anyone experince this before?  Any one know enough about these motors to help out?

I know a bit about engines (primarily gas engines), which makes this all the more wierd to me.

Any help would be greatly appreciated.

[Ray & Sandy Erps]

Had the same problem with hot starts.  The battery cables are undersized.  Heat increases resistance in the starting motor.  There are several fixes discussed on the board.  Some folks install a starting battery close to the engine.  I ran another set of cables to the starter and didn't have any problems after that.  If you do a search for "hard start" or something like that, past discussions should pop up.

[sdaly66]

Thanks folks.

[Craig Illman]

I agree with Ray. The factory crimp connections on my '91 were pretty marginal. Before you start running new cable, and if you have enough extra length, cut off the existing lugs/terminals, strip back the wire and re-crimp new terminals on both the positive and negative paths. My boat didn't have tinned wire, your hull number is even older. You likely have significant corrosion at some or all connectors. Ideally, you crimp, solder and heat shrink every connection.

Craig

[Sundance]

Had the same problem.  Clean all the connections, relpace or redo any splices that may be in the wires from the engine panel to the engine, put in a new fuse between the start button and starter...starts like a champ both cold and hot now.  It comes down to the increase in resistance in the wires when hot making a poor connection a real problem when hot.

[jkar]

I had the same problem, turns out that cylinder #2 was shot.  I now have a new engine.  I will be parting out the old engine as everything else is in perfect order.

[Ron Hill]

sd : I have the same #4 cables that came with the boat when I bought it 20 seasons ago.  Clean and solder all of the battery cable connectors to the #4 wire and your hot starting problems will go away!!   

[Stu Jackson]

Try this link to the Tech Notes:  http://www.c34.org/mainsheet/pdf/1996_no1.pdf

[Richard Bain]

My problem, intermitent and still an issue, is similar but not the same.
I start the enjine after the glow plug is hot and as I push the start button, the enjine "on" tone is reduced and nothing happens!
Then I try it again 30 seconds later and it is fine. My fresh water boat has no corrosion, so I am stumped. Solinoid?
Thanks

Richard

[Footloose]

Richard,

I also have a fresh water boat that had a similar intermitant problem that you discribe.  We still get corrosion in fresh water although slower.  It was cured by cutting off all of the ring connectors and soldering a shrink wrapping them as has been discribed.  The corrosion occurs between the connector and the wire increasing the electron jumping distance.  A small amount of resistance at high current draw makes for significant power loss.  It only gets worse when the tempurature rises. 

[Ron Hill]

Guys : Crimping is a mechanical connection - soldering is an electrical connection.  Crimp and solder and you have the BEST of both worlds!! 
A thought

[Ken Juul]

For the first few minutes after shutdown the motor will heat up before it starts cooling down.  I think my battery cables are probably not the best, but I have found that when hot it takes about 3 pushes of the start button.  First push gets a partial turn, second push gets a bit more, third (or sometimes 4th) and the engine starts.  My theory is that the first couple attempts introduces enough cold air into the engine to reduce the compression enough to allow the starter to spin the engine fast enough to start.

Replacing the battery cables or new ends is on my winter project list.

[Ron Hill]

Richard : You may have a fresh water boat, but that doesn't mean that your battery cables, connections and connectors are exempt from corrosion.  The connections and connectors at the the batteries most certainly can and will get corroded!!  The other connections will get oxidation (copper turning dark to black) and a single poor crimp will be the "weak link" in your electrical chain.

Just like the battery connections on you auto, the connections on your boat also need to be inspected and cleaned.  The old wives tale about soldered connections not taking the vibration and breaking is a bunch of hog wash (BS).  Nearly every connection on my boat (that I can get to) is soldered and have NEVER had one break!! 
Most recently I've been replacing all of the "blue" splice/connectors to the cabin light wiring and my lighting problems have gone away - by cuting out those connectors and soldering the wires.

A thought.