89 70hp Too much compresion?

[Magnumu]

My son just bought a boat with a 89 70hp Johnson. If plugs are in it will not turn over the motor. We have installed a new starter and connected 2 batteries in series to make sure it is getting enough power. It turn over quickly with all plugs removed. If we install one plug or compression gauge, it will not turn over. Could there be something restricting the exhaust and building too much pressure? The previous owner said it had been sitting for 3-5 years.

Thank you

 

[toddschubert]

Do you have a dirt dobber problem there?

 

[Tim Frank]

The batteries should be connected IN PARALLEL, NOT in series....that will give 24 V.! I doubt you'll seriously damage the starter with 24 volts, but you may damage other accessories.

Check the voltage drop on the starter.

These problems are most commonly wiring-related and a good illustration of the benefit of careful and systematic troubleshooting; an awful lot of perfectly good starters get changed for no good reason.

Try jumping directly to the starter from the battery.

 

[Magnumu]

They are parallel, sorry mistype. Not sure what dirt dobber is? When I blow compressed air through plug holes, we do get it come through propeller housing. Took head off and 5 of 6 exhaust ports flow well, one does not. Trying to figure out how to open that one. Also tried jumping starter straight from battery with same result.

 

[mfkadz]

Dirt Daubers are those wasps that build clay tubes. They find the oddest places to build their tubes.

mike

 

[emdsapmgr]

Did you test the old starter first? Connect it to a known strong battery with a set of automotive jumper cables. If it cranks the engine normally using this test procedure-the starter is ok. Then check the solenoid. On old solenoids, the internal contact tips get burned and will not transfer enough current to crank the engine normally. You may have better luck with a new solenoid. A cheap fix.

 

[Magnumu]

Tried New battery directly to each starter. It turns over pretty good, we get spark from plugs. As soon as any plug is inserted, it will not turn engine over.

 

[Bosunsmate]

Any plug inserted... Your starter is gone burger.
You can turn these over by hand with all plugs in

 

[Magnumu]

That is what has me puzzled, bought new starter and it is the same way. Can't figure it out

 

[Bosunsmate]

That is what has me puzzled, bought new starter and it is the same way. Can't figure it out

what did you do for the ground/negative?

 

[mfkadz]

Does this motor have a pull cord start option? Have you tried to hand pull it with and without plugs?

When you hit the starter with the juice it it jump? They have piles of torque. It should not just sit there and spin like a simple electric motor.

mike

 

[Magnumu]

Used jumpers from battery to starter on both neg and pos. Local starter repair shop tested starter as well. Still bought new starter and battery with same outcome

 

[Magnumu]

I wrapped cord around flywheel it turns harder with plugs in but still turns.

 

[toddschubert]

What exactly happens when you start w plugs in? Does the bendix operate correctly engaging the flywheel gear? Is that when it stops or does it not even engage ?
I mentioned dirt robbers cuz they could possibly have gotten into exhaust tubes and built their amazingly strong egg hatchery there blocking output. But if it turns by hand or cord with plugs in that's not the problem

 

[racerone]

Lower unit problems ??

 

[Bosunsmate]

I wrapped cord around flywheel it turns harder with plugs in but still turns.

well if you can turn it by hand a new starter and a new battery would be able to turn it hundreds times as fast as a person.
Post a video if you can showing turning by hand with plugs in and out and also the starter attempting too

 

[doonhamer]

Really green when it comes to outboards a new game for me, is there a safety cut out (neutral) ,for if the motor is gearbox is engaged when starting , if so , is it ( cut out ) adjusted properly.

 

[mfkadz]

There's usually a lockout switch in the remote control that get's engaged when you are not in neutral. The engine would not turn at all if not in neutral.

mike

 

[Magnumu]

With plugs in starter engages and turns very slowly, maybe a revolution every 3_4 seconds, acts like way to much compression

 

[mfkadz]

It sounds like the exhaust is obstructed.

Do you get any blowback out of the carbs when you try to turn it over?

mike