Onan twin running on one cylinder. I'm stumped...

[Kbeitz]

I think Onan quit selling twin coils years ago or I would have a new one.
Kohler still makes one. Maybe I'll try one of there's .

[Remle]

 As you say swapping the wires should make the problem switch sides, but it does not. That leads me to ask, does this model have an ignition trigger? Seems I read that it has a two circuit system, one side could be bad ? Be careful testing that, as they say that they are easily destroyed. First check the wiring connection for corrosion inside.

[Kbeitz]

As you say swapping the wires should make the problem switch sides, but it does not. That leads me to ask, does this model have an ignition trigger? Seems I read that it has a two circuit system, one side could be bad ? Be careful testing that, as they say that they are easily destroyed. First check the wiring connection for corrosion inside.

One set of points for both sides Fires both plugs at the same time.No ignition trigger.
No flywheel magnets for spark.

[Ox]

Not much left to try.

Is the piston moving up and down?  ;)

[grouch]

Fire, fuel and air. If it gets those in the proper amount and at the proper time, it'll run.

One or more of those is not arriving on time or in the right amount.

After it fires, it has to be able to fart. Clogged exhaust won't keep it from firing, but will stop it from running afterwards.

[whitepine2]

May-be you can give it a "hot supper" hook it to another engine by belt and
let it turn over while you tinker with her,this might give it some incentive to
fire up. Had a Wisconsin V-4 that we had to do this to and this made her come
coco just needed a little power boost. Keep trying it's just gotta go.

[Magicman]

Oh No!  Getting it to run would ruin a perfectly good topic!   :

[Andries]

Does the coil look like this one?

The new ones from Cummins/Onan look like this . . .

[Kbeitz]

Does the coil look like this one?

The new ones from Cummins/Onan look like this . . .

That looks like a Kohler coil. My coils look like this.



 

[Andries]

That looks like a Kohler coil. My coils look like this.

The box it came in said Onan/Cummins.
It was bought at the local Cummins dealer.
I don't own any Kohler motors.
You may have identified your motors problem . . . ?

[whitepine2]

Oh No!  Getting it to run would ruin a perfectly good topic!   :

True true you have a good point,but I gotta keep K interested he seems like he's going to stall all this giving up talk,all done,no way I say,no way.

[Al_Smith]

Does that thing have an impulse carb like a Briggs ?If so they can give you fits if the diaphragms get funky .It's a float carb with a diaphragm for some reason .The parts are cheap if that be the case .If it's firing both plugs and only putts on one the only thing left is fuel delivery .

[Andries]

The impulse pump on my 24 hp Onan, looked like this:


I replaced it with this:

[Kbeitz]

Well I got it running... But I have no idea why.
First thing today I put a different set of points in it
out of one of my running tractors. It made it worse.
I put the point back in the donor tractor and it worked
fine. I was about to give up and I had another parts
engine with points. I looked it over and thought that
it might be easier to remove the whole point box instead.
Well the definitely was not easier . Then when I tried to
start the engine it was running again on one cly. But this
time the engine started smoking real bad. Then I noticed
that it was running on the front cylinder and not the back.
this is why all the smoke. From all the running on the back
the front loaded up with gas and oil. Then I seen the back plug
wire was not on all the way. I put the wire on and it fire right
up and ran fine... So... What did this problem have to do with
the point box?. I'm thinking maybe it had a bad ground.
But why did the spark look so good but would not run the front
cylinder but would run the back so good. I tried putting the other
coils back on and they all work great. Same with my spark
plugs. they all work good. So I'm really lost on why changing
the point box fixed my problem. This was the forth set of point
and condenser that I tried.

Non working points box.



 


A ride the the mountain top.



 

Thanks for everyone's help.

[Magicman]

Oh No, there goes the Neighborhood!!!   :-\

[Kbeitz]

Anyone have any idea what might have happened ?
I'm still stumped... Why did that fix it?

[Andries]

Hard to say why it works now, but you get points (get it?) for hanging in there.  8)

[whitepine2]

Anyone have any idea what might have happened ?
I'm still stumped... Why did that fix it?

Like you said faulty point box,what else could it be with all the work you did on it
it should run like a new one. I just knew you could do it but we all like a challenge
what fun would it be if it was simple?
                                                        HURRAH GOOD JOB! 

[Kbeitz]

But I like to learn from what I did.. I learned nothing...
A stupid little aluminum box should not control where
a spark goes. No logic... I'm not even sure it was a spark
problem because I seen a nice blue spark at the non running
plug at all times. Swapping the spark plug wire from one side
of the coil did nothing... I wont sleep tonight.

[red]

You have to get some sleep because you have to get up and do it all over again tomorrow. Plus the World did not End today . Life is Good.

[Magicman]

Apparently the box was not (fully) grounded which means that the condenser was not either.  Of course it should spark without the condenser, but the points would suffer.  Clean the grounding surface and reinstall the old box.

EDIT:  Well that doesn't make sense because the same points and condenser services both sides??

[Al_Smith]

Correct me if I'm wrong but as I recall and it's been over 30 years the points set up on the top of the engine .The works are transmitted via shaft from the cam or crank,but I never got into one that deep .The one and only was a welder with an Onan but labeled as something else,Miller maybe  .It was a good machine have to say that .Took me a while to figure out where the points were ,just a little tweek,they were not closing all the way.Glad it putts on two.

[Kbeitz]

Funny thing... both engines the one I was fixing and the donor engine has
What looks like a factory gasket between the engine and the points box.
You would think that that would defeat the box ground. 


Yes the points box is on top of the engine mounted under the carberator.

[luvmexfood]

Anyone have any idea what might have happened ?
I'm still stumped... Why did that fix it?

Gremlins. Probably the same ones who slip into my kitchen and swap out my plastic storage container lids so that I have containers and lids that won't fit each other.

[whitepine2]

But I like to learn from what I did.. I learned nothing...
A stupid little aluminum box should not control where
a spark goes. No logic... I'm not even sure it was a spark
problem because I seen a nice blue spark at the non running
plug at all times. Swapping the spark plug wire from one side
of the coil did nothing... I wont sleep tonight.

I know you wont sleep I wouldn't ether till I really knew,but I also know that you
will get the answer sooner or later,just let us know.