Compression release

[Anonymous]

quote mgsolakis:

My issue is that I can’t use the electric start without a solenoid. So there is no way to accurately test compression. Plus I was hoping that an automotive solenoid might help me get the electric start working. But that seems like a bad idea as well by the sounds of it.

You can use jumper cables (minus to ground, plus to the starter).

The correct solenoids aren’t that expensive (multiple sources available). Do you have the original solenoid box? If not, you don’t need to worry as much about getting one that fits! If you do, what year is your engine?

[mgsolakis]

Won’t it spark like crazy without a solenoid?

[Mumbles]

quote mgsolakis:

Won’t it spark like crazy without a solenoid?

A little bit. Jump it at the battery to avoid a chance of fire.

[mgsolakis]

Ok I’m confused, why jump it? Why not just hook it to the battery? And use the button start?

[fleetwin]

You could just hard wire the starter directly to a battery, except for the negative terminal on the battery. Tap the negative terminal to the battery post for a few seconds to crank the engine/check compression.

[chris-p]

quote mgsolakis:

Ok I’m confused, why jump it? Why not just hook it to the battery? And use the button start?

You can, IF you have the proper solenoid, which you currently don’t. What the guys are recommending is for a quick compression test.

Always hook up the positive, then tap the neg to battery as mentioned. Sparks less.

[legendre]

quote Mumbles:

quote mgsolakis:

Won’t it spark like crazy without a solenoid?

A little bit. Jump it at the battery to avoid a chance of fire.

Err.. the hydrogen gas produced in a lead-acid battery is definitely an explosion hazard.

The drill when jump-starting a vehicle goes like: Bat Red #1 -> Bat Red #2 then Bat Blk #1 -> Engine block / alternator bracket #2, in that exact order. This ensures that any arcing occurs at the block / bracket, and away from either of the batteries.

[chris-p]

Better than a gas soaked 2 stroke outboard though! lol

Ill take my chances with the minute amount of hydrogen, if any. Never heard of anything happening like that.

I have seen outboards catch fire from sparking near them though! Ask anyone that has tested spark with the plugs out and grounded it near the head 😉

As stated, use the negative of the battery for the final connection when jumping the starter.

[Mumbles]

A battery only gives off hydrogen when its charging. Doing it outside in a breeze shouldn’t make it blow up like the Hindenburg.

[dan-in-tn]

We ain’t testing cars! Leaky smelly outboards. If you are worried about hydrogen gas, put a fan in front of the battery.

Dan in TN

[Author]

Posts