Trouble Cranking with Plugs In

[HighTrim]

Evening Gents,

I have run into a problem that I have not seen before.

Currently working on a 1958 35hp Evinrude 35515

Before I begin, I would like to mention that this motor is on a test stand, not installed on a boat.

With the plugs out, the motor will spin as it should. Once I install a plug, and my compression gauge, and try to crank it by jumping the starter from the battery, she will barely crank. Classic symptoms of bad connection, faulty wiring, but I am jumping it direct from a known good battery, that has been load tested, with heavy gauge jumper cables, in pristine shape.

My initial thought was the starter, so swapped it from a starter from another 40hp I have, yet same problem. The piston is not hitting the plug, it is not a sudden stop, just feels like there is too much compression to spin.

Im not sure if possibly the exhaust ports are clogged? Im running out of ideas here.

 

[kenmyfam]

Re: Trouble Cranking with Plugs In

Does sound like a classic bad connection problem. What kind of voltage are you getting at the starter ???

 

[Jayrock]

Re: Trouble Cranking with Plugs In

I feel dumb to mention this, but are the ground points where the starter mounts to the crankcase clean and tight? I am sure you made certain of this, as you just changed the starters. Possibly try another battery or another set of cables. Its a classic sign of not being able to carry a load, typical of a bad connection. I am curious as to how this turns out...

 

[HighTrim]

Re: Trouble Cranking with Plugs In

Getting the full 12.65 at the starter. Not really any connections to worry about as Im jumping it off the battery, bypassing ignition and harness.


Jay I have added a couple extra ground straps as well to rule that out. Im going to dismantle the starter and see what I find.

 

[kenmyfam]

Re: Trouble Cranking with Plugs In

Did you try a rope on it ???

 

[HighTrim]

Re: Trouble Cranking with Plugs In

Yes, tried the manual start as well. Same thing. Plugs in, hard to pull. Plugs out, no problem.

Compression relief installed and working as it should, but of course, that wouldnt affect the electrical start anyways.

 

[jonesg]

Re: Trouble Cranking with Plugs In

You check the starter gear meshing with the flywheel for binding ?

 

[Mas]

Re: Trouble Cranking with Plugs In

Just for giggles, I would try another battery. MAybe swap one out of your car?? You can get 12 volts with 8 "D" cell batteries in series...but it's not enough umph to turn anything...not enough amps.

Just a thought,

Mas

 

[kenmyfam]

Re: Trouble Cranking with Plugs In

What's the history with this motor ?? New to you or used to run for you ???
How does it go around by hand without the plugs in ???

 

[78 mckee]

Re: Trouble Cranking with Plugs In

Are the cables, connections, or the starter itself getting hot during the cranking? This would indicate a high resistance (poor connection) or, in the case of the starter getting hot, a bad starter. Where you have heat you have resistance. Where you have resistance you have voltage drop. These older motors do have high compression and require more force to turn them. The starter, cables, and battery need to be optimal to fuction correctly with these old motors.

 

[HighTrim]

Re: Trouble Cranking with Plugs In

Shes Alive..

I started by dropping the gearcase, what a rats nest, literally! Havent seen so much junk in a gearcase before. Mouse nest, hornets nest, etc... Still issues cranking.

Then I went out to princess auto, bought 2- 5' lengths of 2 gauge welding cable, brand new battery posts, and 2 large welding copper terminals. Sanded down the starter post and washers, connected the terminal, sanded down a good ground on the starter bracket, and woila! She spun like a mad hatter on steroids.

Very strange because I used the same cables just this week to test the compression on a 62 40hp, a 69 40hp, and a 63 40hp. This motor needed some more voltage from the rest for some reason or another. I noticed the starter post was a bit wobbly as well, Ill take it apart and rebuild it to be sure the buyer of this has no issues. 100psi on both holes, cleaned the carb, new ignition, new water pump, gearcase oil, plugs, and am going to run all new wiring. Whoever buys this one should be maintainence free for a couple years anyways

 

[Tim Frank]

Re: Trouble Cranking with Plugs In

Clearly once that motor realised that you shop at Princess Auto it realised that resistance was futile and it threw in the towel and decided to cooperate...

 

[HighTrim]

Re: Trouble Cranking with Plugs In

LOL, everyone loves Princess Auto....except my wife

 

[kenmyfam]

Re: Trouble Cranking with Plugs In

Glad you got it sorted.

 

[Mas]

Re: Trouble Cranking with Plugs In

Let me in on the secret...Princess Auto????

Mas

 

[jrs_diesel]

Re: Trouble Cranking with Plugs In

It's a Canadian retail chain:

http://en.wikipedia.org/wiki/Princess_auto

The other one I hear about often is Canadian Tire.

 

[Mas]

Re: Trouble Cranking with Plugs In

That helps...I was imagining something totally different.

Mas