Starter Bendix

legendlc
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Starter Bendix

Postby legendlc » Sat Apr 18, 2020 4:06 pm

On my project boat trying to get the engines started for the first time in 12 years o realized my starters were to slow to start the engines. I took the port side apart to find the brushes all corroded and stuck, lots of rust etc. I cleaned everything up good and lightly sanded and everything was moving freely and nice. Upon testing with cables I noticed that the Bendix on the starter isn't really moving in and out that much at all. From my untrained and completely clueless eyes it appears that the Bendix is retracting enough to disengage the flywheel. Upon taking it apart again etc and sanding, polishing, greasing etc everything it appears that it can't really move that much from design. I get maybe a quarter of a inch or so of travel in and out but that's it and I can't really see it could move much more then that. I will admit this is all new to me but wanted to see if I was missing something obvious here. Thanks for any insight given.
1978 37 Double Cabin
Lake Cumberland KY

Fastjeff
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Re: Starter Bendix

Postby Fastjeff » Sun Apr 19, 2020 7:32 am

What usually causes that is a dead starter motor without the ZAP to fling that bendix out properly.

Jeff
"We live at the bottom of an ocean of air, not at the top." General Marvage Slatington

legendlc
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Re: Starter Bendix

Postby legendlc » Sun Apr 19, 2020 10:07 am

Jeff, I think my post was a bit confusing. It appears that the Bendix is out but it doesn't appear to be retracting enough to get out of the flywheel.
1978 37 Double Cabin
Lake Cumberland KY

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bcassedy
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Re: Starter Bendix

Postby bcassedy » Sun Apr 19, 2020 7:41 pm

I believe (based on long ago experience with Ford starters) that the motor relies on 12v to activate. The bendix is spring loaded, meaning that when 12v is applied, the bendix should spring forward, engage the teeth of the flywheel, and the starter spins the flywheel. Removal of the 12v deactivates the starter and the bendix is then pushed back into position.

With this scenario, couldn't you remove the starter, connect ground from a battery to the starter chassis, and put 12v to the positive lug (use sufficiently large jumper wire)? With this process, you should see the bendix slide back and forth. The 1/4" movement you indicated would, IMHO, be insufficient to fully engage or disengage the teeth of the flywheel.
Note - with the starter removed you should be able to see the flywheel and measure the width of it. The bendix would need to travel far enough to fully engage the flywheel's teeth. To fail to do this would mean the bendix's teeth would only partially mesh with the flywheel and that'd lead to stripping of the teeth, on both flywheel and bendix.

Or, as this is a shadetree opinion, am I off base folks?

Bill
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legendlc
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Re: Starter Bendix

Postby legendlc » Sun Apr 19, 2020 8:35 pm

Bill you are 100% correct. With the starter removed the Bendix spins like crazy when connected to the battery but it barely travels in and out at all. I Cleaned everything I could but I did not take the Bendix apart fully. I tell you what I get stupider and stupider by the day when it comes to this boat lol. I thought I knew how starters work from working on cars in the bast in the shade tree as you say. Then I take this one off and I was thinking that half the parts must be missing lol. It is a strange thing with the very aggressive cut gear used to force the Bendix forward with momentum etc. I think it must be time for a replacement. I was looking to see if I could find a newer style high torque gear reduction unit if it could fit in the space and I could find a CCW unit also. I had hoped to clean my current unit but that seems to not be 100% of the solution.
1978 37 Double Cabin
Lake Cumberland KY

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Re: Starter Bendix

Postby Fastjeff » Mon Apr 20, 2020 6:58 am

bcassidy is correct: the bendix is supposed to move towards the flywheel when activated, but it's moved back into rest position by the motor starting up.

I still think your starter is whipped electrically.

Jeff
"We live at the bottom of an ocean of air, not at the top." General Marvage Slatington

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bcassedy
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Re: Starter Bendix

Postby bcassedy » Mon Apr 20, 2020 7:19 am

Thanks guys... It's nice to be correct once in awhile..

... I gotta tell the admiral about this one.

My experience with starters (for automotive) also included a Rube Goldberge setup when I used to plow snow. Wanted to also salt parking lots but didn't' want to plow money into 'store bought' spreader. Built my own, sprayed interior w/ underbody coating. To spread salt I rigged a jeep starter switch in the truck cab connected to a straight shaft starter that I connected a piece of pipe to that ran to the top of the spreader into a bearing for stability.
It worked great (tho too long a run period sucked a lot of juice out of the battery! :shock: )...
... too great! The salt came off the spreader plate with such force, it would "salt blast" paint off! Had to cut a piece of dump truck tire flap to deflect salt downwards.

Good times!

(Sorry if this is more of a non- boat story... mea cupa.)

Bill
Bill & Sharon Cassedy
"Sunset Seeker"
'88 32' Sedan Bridge
Located in Aurora, In.
Twin 318cu in Chrysler
1.5:1 Velvet drive trannies
Fresh water only

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Re: Starter Bendix

Postby Fastjeff » Mon Apr 20, 2020 1:57 pm

Neat idea, but this is what you really needed.

Jeff
supersnowthrow-2.jpg
supersnowthrow-1.jpg
"We live at the bottom of an ocean of air, not at the top." General Marvage Slatington

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Re: Starter Bendix

Postby legendlc » Wed Apr 22, 2020 9:03 pm

Newly rebuilt starter in place, and for the first time in 12 years there was fire in the cylinders... Now it may be 180 degrees out of time because all it does is backfire as soon as you hit the switch. But.. I have fire for the first time. Woohoo
1978 37 Double Cabin
Lake Cumberland KY

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Re: Starter Bendix

Postby Busia » Sat Apr 25, 2020 3:54 pm

legendlc wrote:Newly rebuilt starter in place, and for the first time in 12 years there was fire in the cylinders... Now it may be 180 degrees out of time because all it does is backfire as soon as you hit the switch. But.. I have fire for the first time. Woohoo

No, No, No ! You are not 180 degrees out,You just have the spark too far advanced (or the mixture too lean or the octane too low, or two plug wires swapped) Remember, if you are 180 degrees out you will be firing on the exhaust stroke and nothing will happen. Just turn the distributor a little bit in the direction that the rotor turns. Every degree you change the distributor will be two degrees of ignition timing ( because the crank goes twice as fast as the distributor. ) Just loosen the clamp and bump it a bit. When you get it running and warmed up, you can fine tune the timing and the carb.
BUSIA
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