Page 1 of 1

Onan B43M on 446

Posted: Tue Nov 08, 2022 3:23 pm
by Harry
I've been having a problem with the starter on the Onan which is on my snow machine. I went to start it and it wouldn't turn over. I put the battery charger on it for an hour and it still wouldn't turn over. I put the charger on start position, and it still wouldn't turn over. I pulled the plugs and it turned over easily with just the battery. I switched batteries from another tractor and still no cranking. The starter seems to work fine but not under a load. The starter relay appears to be working fine. Before I pull the starter, which is a PITA, I thought I would write this post and throw it out there to the members for ideas.

Keep the :peace: :cop:
Harry

Re: Onan B43M on 446

Posted: Tue Nov 08, 2022 3:59 pm
by DavidBarkey
Harry wrote: Tue Nov 08, 2022 3:23 pm I've been having a problem with the starter on the Onan which is on my snow machine. I went to start it and it wouldn't turn over. I put the battery charger on it for an hour and it still wouldn't turn over. I put the charger on start position, and it still wouldn't turn over. I pulled the plugs and it turned over easily with just the battery. I switched batteries from another tractor and still no cranking. The starter seems to work fine but not under a load. The starter relay appears to be working fine. Before I pull the starter, which is a PITA, I thought I would write this post and throw it out there to the members for ideas.

Keep the :peace: :cop:
Harry
Use a know good battery fully charged and car rated jumper cables. Cables directly to the starer eliminating the tractor side of things . If it still will not crank with plugs in , are pulling the starter . If it does , then use the cables to by pass the ground from the battery to the block and then to the starter . If it cranks then you have a bad connection or a bad cable end . If it does not do the same for each of the B+ cables to the solenoid and the the starter . If that does do it cross the solenoid cable terminals to see if the fault is there . I have had many cable fail in the terminals where you can not see . Same goes for partial contact in the solenoid . This will allow you to diag. with out doing a hot (live) voltage drop test , which can be a pain to do on the tractor.
Hope it is just a bad cable .

Re: Onan B43M on 446

Posted: Mon Nov 21, 2022 1:29 pm
by ras101
Hi Harry, I tend to get what you are suffering every year! My snow tractor sits all summer with little to no use and the first time I try to start (if I am honest a few times I try to start) all I get the the famous "click" an nothing. Got past this now, just gave up! yes just what I said... All I do now is turn the key to start a the beginning of the season and then jumper the solenoid! seems counter productive I know and totally against every fiber in my body but it works! My GT starts like that for the past 3 years (including this year) . After a couple of starts like this it is good to go for the whole winter. I have tried (I am/was an electrical engineering manager by trade) it works fine for the whole winter. My only analysis is that the safety switches become corroded and need time to heal. Just done that yesterday again to move my 446 snow machine to its winter position.

Re: Onan B43M on 446

Posted: Mon Nov 21, 2022 2:17 pm
by Harry
I just picked up my starter this morning from the shop. He told me the bushings were worn to the point that the armature was starting to hit the magnetic. He replaced the bushings, brushes and the end cap. I find it hard to believe that it was that bad in five years since he rebuilt. It's on a tractor that only gets started in the winter to move snow. :hm:

Keep the :peace: :cop:
Harry

Re: Onan B43M on 446

Posted: Mon Nov 21, 2022 3:25 pm
by ras101
That, my friend really says that you have been scammed! Never have I ever had to replace a starter, let alone bearings etc, on my tractors. Unless you are cranking these over continuously there is no way they would fail that way!

Re: Onan B43M on 446

Posted: Mon Nov 21, 2022 3:29 pm
by DavidBarkey
Harry wrote: Mon Nov 21, 2022 2:17 pm I just picked up my starter this morning from the shop. He told me the bushings were worn to the point that the armature was starting to hit the magnetic. He replaced the bushings, brushes and the end cap. I find it hard to believe that it was that bad in five years since he rebuilt. It's on a tractor that only gets started in the winter to move snow. :hm:

Keep the :peace: :cop:
Harry
Oil lite bushings quality for the size may not be what it use to be . Or because only used in the winter the oil impregnated in them to viscus to be useful at cold temps . Hard to know for sure .

Re: Onan B43M on 446

Posted: Sun Nov 27, 2022 12:48 pm
by Harry
Yesterday I took some time in the shop to install the recently rebuilt starter. It was still a bit of a pain to install the bolts and set the lash on the flywheel. :pullhair: I cranked it over and it fired right up. Bring on the snow now, Harry's ready! :thumbsup:
Keep the :peace: :cop:
Harry

Re: Onan B43M on 446

Posted: Sun Nov 27, 2022 4:34 pm
by JSinMO
I sure does seem odd that the starter would be worn out with such little use, but at least it’s good now. Let’s hope that’s that the last time you have to mess with it for a long time.

Re: Onan B43M on 446

Posted: Sun Nov 27, 2022 8:40 pm
by Eugen
That must've felt good @Harry !

You know, I'm thinking, what if the spring mechanism for the starter gear got stuck and the starter kept on turning with the engine, occasionally? That would explain getting broken so fast.

Re: Onan B43M on 446

Posted: Fri Dec 02, 2022 8:43 pm
by ras101
Harry, still think you might be back where you are right now trying to start (really hope you are not!) just jumper the solenoid thou and it should start with little to no issues. I really think our main starting issues are more to do with our switches than anything else. Just think about it guys everything wears out eventually and our safety switches are no exception. The 1970-80 tractor shave a few to worry about so for us we don't even think about that -do we? (be honest here). For me with a1978 446 if I don't get ON the GT and press down the brake all I get at best is a solenoid that clicks - do you get that too?? When I jumper the solenoid It starts --wow! your choice.Oh by the way I usually still get on the GT and start sitting in the seat but just saying...

Re: Onan B43M on 446

Posted: Sat Dec 03, 2022 1:09 am
by Gordy
ras101 wrote: Fri Dec 02, 2022 8:43 pm Harry, still think you might be back where you are right now trying to start (really hope you are not!) just jumper the solenoid thou and it should start with little to no issues. I really think our main starting issues are more to do with our switches than anything else. Just think about it guys everything wears out eventually and our safety switches are no exception. The 1970-80 tractor shave a few to worry about so for us we don't even think about that -do we? (be honest here). For me with a1978 446 if I don't get ON the GT and press down the brake all I get at best is a solenoid that clicks - do you get that too?? When I jumper the solenoid It starts --wow! your choice.Oh by the way I usually still get on the GT and start sitting in the seat but just saying...
There was a discussion on the old group about the Onans and the click no spin on the starter. You are correct about the switches, but also wire connections, they get dirty and can carry 12 volts but at greatly reduced amperage. One of the guy's brought up a JD fix for their Onan powered tractors. It was to install a relay. The primary coil is hooked to ground and the wire coming to the the solenoid, the secondary of the relay is hooked to the solenoid and battery positive. Here's the link.

https://www.casecoltingersoll.com/threa ... ion.69338/

:cheers:
Gordy