!996 Force 90 difficult to start, seems starter will not overcome compression.

[Rookieboater22508]

We bought an old pontoon boat August 2014, we got it running by 8/15. The 96 Force 90 motor ran ok but wouldn't start it sounded like the started failed it wouldn't turn the flywheel. we replaced the starter with one from the internet and the motor started right up.....The second starter seems to have failed in mid September of 2014. I'm no wizard but I would think that starters should last longer than a month. I noticed the bendix would engage the flywheel and try to turn it until it got to the part where the 1st and 3rd pistons are really compressing the air/fuel mix and the bendix would bind and the starter would squeel something awful. we would have to bump the fly wheel backwards a couple of teeth to get the bendix to release. I fear that the starter is bad again. I've checked the wiring and it all looks great, I even used jumper cables to jump around the soliniod and the wiring and I get the same result. I don't know what to check next could this be an exhaust problem? oh I just finished changing the oil and the impeller in the lower unit and when I had the bottom unit off it was still hard to move the flywheel by hand when the 2 pistons were on the upstroke with the plugs in. I have taken the plugs out and the flywhell moves just fine no sounds of scraping or dragging. What's the next steps here?
Thanks!

 

[Frank Acampora]

If the engine is turning free with the plugs removed, very likely it is not the engine itself. And remember: That same starter is used on all 3, 4, and 5 cylinder engine. SO, if it is functioning properly then it should have plenty of power to crank the engine.

First start with the basics: Remove the battery connections and clean them. Then, I like to put a lock washer on the posts to "bite" into both the battery terminal and the wire. Remove the battery wires from the starter solenoid and block ground--The negative is grounded to the block, isn't it--and again clean them well. Be certain the battery has at least 13 volts before using it. If it has less than 12 volts when fully charged, replace it.

Lastly, just because you can not use the starter does not mean you can not use the boat. The engine ignition is self energizing. With someone to push the key in to "choke" position you can pull start it with the key in the RUN position.Use a relatively long rope with a good sturdy handle. Brace your foot on the transom or the engine and pull with both hands. And don't sat it is too difficult: Bosh! I am 70 and do it once a year on my engines just to be sure I still can.

Now, after doing the basics if the starter does not crank well, the brushes or brush springs may be worn. Excessive cranking can wear brushes and holding the starter in the stalled position OR running it on too low a voltage can heat the spring and make them luse their temper thus keeping the brushed from making contact with the commutator. Remove the end cap and check the condition of the brushed. Clean the commutator with very fine sandpaper. Search other past posts to see how to re-assemble the starter.

 

[jerryjerry05]

Before you do what Frank suggests. After cleaning the contacts.
Do a compression test on the motor.
Uneven comp on 1 cyl. can cause that problem.

 

[Rookieboater22508]

I have tried what Frank suggested and the connections are all clean, I tried to pull start the engine and i couldn't turn it one turn with the rope. I can however turn it slowly by hand but can't turn it fastenough to start because it gets real hard to turn half way around. What can the issue be if the starter can sturn the flywheel with the plugs removed but when all three are installed it won't turn it over?

 

[Frank Acampora]

Try removing the bottom two plugs and with the ignition off, jump the solenoid and try cranking the engine. Then repeat for the other two cylinders. This should isolate the cylinder giving problems.

Now, it is a reach, buy it is possible that one cylinder has lightly rusted. Under no compression the rings may glide freely but under compression the pressure will force out the top ring causing it to catch on the rust. MOST times with a lightly rusted cylinder the flywheel will jam partway around with or without the plugs. You may need to remove the cylinder head and physically look at the cylinders.

Are you certain you are using the correct length surface gap spark plugs? A plug that is too long will contact the top of the piston. I believe the correct plug is a Champion L76V or an NGK BUHW--but I am not certain for 1996 so look it up.

 

[Scaaty]

I'd back up and go to the source power to starter. Like the battery. MM on showing anything under 12.35 is way low on voltage. BUT? I seen batts that showed good voltage, but volts don't start any motor "cranking amps" do! Toss a load tester on it..(only $35 bucks and if ya own anything with a battery, get one). Or take it to Autozone and they will test for free. Again seen seems good batts voltage, but a load tester shows 100 cranking amps. and that aint gonna cut it. Have you tried a known good batt?

 

[jerryjerry05]

Battery load tested?
Do a compression test.
The first step in diagnosing problems in any outboard is a compression test followed by a spark test.
Low comp on 1 cyl. will cause the problem.
Post the results.
I think Auto Zone loans testers.
They also load test batteries.

 

[Jiggz]

Based on the history of your problem, when you initially had the same problem last year you were able to fix it with a new starter until the new starter also started displaying the same symptoms a month later. Presuming, the symptoms are all the same wouldn't it be fair to conclude that the starter could be the problem again? And the fact the new starter is not an OEM but an aftermarket probably made in China, it's not impossible that the new starter did not last as expected.

If you still have the original starter, you can try overhauling it and making sure the brushes are still in good shape and the commutator properly cleaned. Or if you have a good working starter (or borrow one) you can try that for troubleshooting. But I still insists you use the OEM starter if it's still repairable or get an OEM from wrecking yards.