Generator starter, Rolling the Dice!

[Delta Riverat]

Previously reported that once I had fixed the alternators, did the house Lithium conversion and added solar the generator (which previously ran) no longer started. The stop solenoid worked and the preheater worked, just no crank.

I got my mechanic friend over and we determined there was a start signal but no action. This is a 1979 Onan MDJE 7.5 with a Prestolite starter that seems to be in very short supply.

So I took a gamble, rolled the dice on this spiffy (Chinese no doubt) gear reduction starter off ebay. My friend does not want to visit my boat anymore than he has to and suggested it would be good to have something to install when he comes next, so I rolled the dice -

Looks like they put a PM DC motor on top with the solenoid on the bottom and the gearing on way to the clutch. Pretty clever eh?

Well if it works I'll be happy and if it don't I'll have the yard remove the generator in pieces as needed.

These old boats...

 

[Portage_Bay]

If the spiffy new starter doesn't work check into a rebuild. I had a MDJE 7.5 on the previous boat. Had the starter rebuilt maybe 4 yrs ago. I'll try to dredge the rebuilder's name out of my memory.

 

[Lepke]

A China starter should be ok. I've used a few. I have one on my Onan MDL3 that's about 15years old. I had the original rebuilt for a spare.

 

[Delta Riverat]

Thanks guys, you give me more hope than I had when I ordered it -

Working on this thing is a pain with the sound shield crap in the way and the starter being on the side that's close to the bulkhead. My buddy is smaller, younger and stronger than me and he ain't having fun. For me it would be impossible

 

[Delta Riverat]

The starter was delivered today in good shape and I have to say I'm impressed. Interesting design, they have the solenoid direct on the pinion gear which moves forward and back like it should and when you turn it you can know that there is a gear reducer between the motor and the pinion because of the sound.

If it fits I think it will work -

 

[Portage_Bay]

If it doesn't work I might have a starter for you. Previous boat had an Onan MDJE 7.5. I bought a running take out only to find out not all MDJE 7.5s are the same. The whole thing has just been taking up space in my shop and needs to go. If I can find someone to take it all that's what I'll do. Parting something out is such a PITA and I just want it gone.

 

[Delta Riverat]

Today we got the old starter off and it was not easy. We had to adjust the mounting plate on the new starter and it still wouldn't fit. Some brackets needed to be modified and all was looking good until the signal terminal on the solenoid broke. Well it didn't break off it just came unglued from the casting.

So, I will fix the glue with some epoxy and we will have at it again. Today was 3 hours in the ER and we ain't done yet.

 

[Duvie]

First thing I did when I bought my Californian was to pull the sound shield off the MDJE and throw it overboard (I was on the hard). Granted the machine was a lot louder but this made maintenance and repairs a breeze. The previous owner had constant issues with it and paid the marina large sums to work on it. Marina staff said the majority of the labor cost was removing sound shield panels to gain access.

Every time I look at a boat, I look at engine access. Nothing worse than struggling with something because it was not designed to be worked on..

 

[JackConnick]

I'm not quite sure why you're not just having the old starter rebuilt? Almost any auto electrical place can do it. Good luck, but I think you're making life hard...

 

[Delta Riverat]

The generator runs! Woo-Hoo -

But not w/o the typical "boat drama" and another roll of "it always takes longer on a boat"

Starter in and cranks engine and engine starts but doesn't stop. Stop switch doesn't work. Battery switch works. Something is not right. Mechanic friend advises to check for stuck relay. He leaves for another job and I get out the manual and see that the engine has a centrifugal starter disconnect switch that activates at 900 rpm and needs to have it's contacts clean and adjusted to .020"

Ah ha! That sounds like the problem so I go back down, remove the cover on the switch and all looks good. Contacts open, gap looks good, WTF?

So I go back up and try it again. This is easy because I can shut it down with the high amp battery switch right at the helm where the gen controls are. And it all worked like it should. Start, stop, re-start and stop.

For some reason it was the solenoid right on the starter that was not releasing and it fixed itself. While down there I saw that the flywheel gear was pretty rough. Rusty and dirty and dry. Me thinks the friction was holding the starter pinion out. There is a small window in the shroud that I used to push the gear a little so I could check the "points" and tomorrow I will grease the gear with some spray lithium grease I got at the hardware store on the way home. And after that I'm going to "power test" the generator because even though I know it now starts and runs I don't know if it makes current flow through wires.

When that is proven I'll put the box back together.

These old boats...

 

[Portage_Bay]

The generator runs! Woo-Hoo -

But not w/o the typical "boat drama" and another roll of "it always takes longer on a boat"

Starter in and cranks engine and engine starts but doesn't stop. Stop switch doesn't work. Battery switch works. Something is not right. Mechanic friend advises to check for stuck relay. He leaves for another job and I get out the manual and see that the engine has a centrifugal starter disconnect switch that activates at 900 rpm and needs to have it's contacts clean and adjusted to .020"

Ah ha! That sounds like the problem so I go back down, remove the cover on the switch and all looks good. Contacts open, gap looks good, WTF?

So I go back up and try it again. This is easy because I can shut it down with the high amp battery switch right at the helm where the gen controls are. And it all worked like it should. Start, stop, re-start and stop.

For some reason it was the solenoid right on the starter that was not releasing and it fixed itself. While down there I saw that the flywheel gear was pretty rough. Rusty and dirty and dry. Me thinks the friction was holding the starter pinion out. There is a small window in the shroud that I used to push the gear a little so I could check the "points" and tomorrow I will grease the gear with some spray lithium grease I got at the hardware store on the way home. And after that I'm going to "power test" the generator because even though I know it now starts and runs I don't know if it makes current flow through wires.

When that is proven I'll put the box back together.

These old boats...

The generator runs! Woo-Hoo -

But not w/o the typical "boat drama" and another roll of "it always takes longer on a boat"

Starter in and cranks engine and engine starts but doesn't stop. Stop switch doesn't work. Battery switch works. Something is not right. Mechanic friend advises to check for stuck relay. He leaves for another job and I get out the manual and see that the engine has a centrifugal starter disconnect switch that activates at 900 rpm and needs to have it's contacts clean and adjusted to .020"

Ah ha! That sounds like the problem so I go back down, remove the cover on the switch and all looks good. Contacts open, gap looks good, WTF?

So I go back up and try it again. This is easy because I can shut it down with the high amp battery switch right at the helm where the gen controls are. And it all worked like it should. Start, stop, re-start and stop.

For some reason it was the solenoid right on the starter that was not releasing and it fixed itself. While down there I saw that the flywheel gear was pretty rough. Rusty and dirty and dry. Me thinks the friction was holding the starter pinion out. There is a small window in the shroud that I used to push the gear a little so I could check the "points" and tomorrow I will grease the gear with some spray lithium grease I got at the hardware store on the way home. And after that I'm going to "power test" the generator because even though I know it now starts and runs I don't know if it makes current flow through wires.

When that is proven I'll put the box back together.

These old boats...

There's a great source of information on these old Onan generators at Smokstak® Antique Engine Community*
I learned a heck of a lot about keeping my old MDJE up and running. The weak point is the control system. That's the part I had faced the steepest learning curve. If I had kept the boat and the MDJE I was going to move the controls off the gen. Those ancient relays suffer from the vibration and they're getting hard to find.

 

[Delta Riverat]

Thanks, I looked at the site and bookmarked it, yeah, lot's of good stuff there.

Today went perfect! I went down and greased the gear after verifying the starter didn't lock first
Greased the gear with the spray though the window while cranking the engine. Found a ground wire broken off the lug and fixed that. The genny started right up and I let it warm up a bit while I disconnected shore power and verified cooling water flow. Then I went back in and switched in the genny all was good. I went around and turned on everything. Battery charger, water heater, all the stove elements and the microwave. I could hear the little change in sound with every add but nothing like it was struggling. Pulled over 30 amps for sure.

The Xantrex inverter/charger told me I was doing 110 volts and 58.5 Hz. The genny was just running with the same sound it makes with no load. Very cool!

This was a very good day. The first in a long time when everything works -

 

[Delta Riverat]

Today I assembled the various sound shield panels lying around the engine room. I thought a lot about getting rid of them but changed my mind during the "run test"

It's a lot louder with the box down. And it's not that bad getting back up again. Had a false start when a panel didn't fit and found I had the top on wrong but hey, that's what DIY repairs are all about eh? My buddy was doing the panel removal while I was fetching something he needed. The "bad boy" starter in the rear has been replaced with this new gear drive unit and I must say I'm impressed. I even googled after the buy and found these things are the new deal. Less than half the weight and size and crank as good or better than the old series wound clunkers. I tossed the old starter in the trash. I'd rather spend $350 for another gear drive unit than pay to rebuild the Prestolite. Especially since the solenoid end cap broke when we were trying to get the wire off. Kinda amazing, the generator still looks good but that starter was rusted up everywhere.

Another cool thing about boats, you learn stuff. I had no idea that gear drive starters were a thing before this project, I was just looking to fix the genny.