Robin Subaru Engine Problems With Solutions

[bbirder]

To stop the engine they ground a wire from the ignition coil at the ignition switch. Check this. You say you get no fire. Does that mean no spark from the ignition coil?

Thanks for the answer Bob. I don't even have any wires from keyswitch hooked up. I have battery to solenoid and ground and spin it over but no fire at plugs. The coils seem to have gone bad. NLA. Engine was running good with probably only 500 hrs on it. It seems that the factory has shut down and very few parts available and they are costly. Really didn't expect to have to change engine to keep my UTV going.I've got a ton of mechanical experience, but these electronic coils mess with my head. I'm old school I guess. It states that the fire to plugs is completed with a resistor that is built into block.???
!-shouldn't I get ign fire with the CP wire disconnected. Seems only for stopping engine.
2- Do you know of a replacement coil or someone who has a blown engine that would want to sell the coils?
I never knew about the obsolescence of the engine and now can't decide how much money to throw at it because I'll still have the same thing.
My biggest problem is I have neuropathy so bad that I use my UTV to get around the place with. Can't walk very far any more.
Any help you or anyone else on forum could give me would be much appreciated.
bbirder.

 

[SpringHollow]

There could be switches etc that need to be hooked up via the key switch wiring harness? If it was working when you removed it, my first assumption would not be that something else has broken so if you think the starter is installed correctly, you might want to actually install the engine and test it.

Ken

 

[xtxpete]

Did you get your UTV going again? Or pushed it off the cliff.....

 

[BobRip]

Did you connect the fuel solenoid to 12 volts? This is needed to turn the fuel on.

 

[bbirder]

Hey Bob,
Everything up and running. I purchased 2 used coils and installed. That fixed my ignition fire problem. Think grandson tied in 12v+ to kill switch and burnt both of them. Fought the wiring for awhile with the help of a great mechanic on another forum. Finally ran two new wires to bring 12v+ to the terminal board by the key switch and everything working except charging system. I think I have to change the alternator coil but for now my battery charger does a nice job. All's well. Thanks for both of you asking.

 

[BobRip]

Glad you got it working. Sorry I was so late on replying.

 

[TwinOaks9]

Don't know if this is the correct thread or not, so if I'm in the wrong place please accept my apologies. I have a 425 with the 25 HP Subaru, purchased new 04/2018, light material bucket, snow blade, mini hoe, 60 inch finish mower, 48 inch rough cut mower. 2.5 acres of lawn, 3 acres of field, lots of trees, slight slopes and in the field some very wet ground. After some early disappointments, which Terry helped quickly with solutions, I love the machine, except it seems to overheat. In warm weather, over 80 degrees, after mowing for about 90 minutes it just dies and will not start. If I let it cool down for about 30 minutes, it starts right up and I can mow again for about another 30 minutes, the longer I let it set the longer I can mow. It acts like it is fuel deprived, as you can sense it is about to stall and if you choke it a bit it will keep running for a few minutes longer. I've changed the fuel pump, even went to an electric pump, fuel is reaching the carburetor. The cooling fan is working well, all filters and fluids are clean and well maintained. Any suggestions would be greatly appreciated.

 

[ponytug]

Sounds like vapor lock in the fuel line. There are a couple of threads on it, but I would start by trying to insulate your fuel line, and checking to make sure that your gas cap is venting correctly. If the cap clogs, you end up pulling a vacuum in the gas tank that makes the vapor lock issue worse.

I think a couple of owners also rerouted their fuel lines, but I think that the factory has routed the gas line differently in different years.

I hope that this helps.

All the best,

Peter

 

[TwinOaks9]

Thanks Peter,

I've checked the gas cap and it is fine, didn't think about the insulating the fuel line, I'll give that a try.

Thanks again,

Dan

 

[ponytug]

Here are two threads to get started;
https://www.tractorbynet.com/forums/power-trac/379743-boiling-fuel.html
https://www.tractorbynet.com/forums/power-trac/398974-fuel-line-setup-4xx.html

All the best,

Peter

 

[MossRoad]

So choking it and it starts running better for a bit would indicate a lean fuel condition, correct? As others have mentioned, and known to be an issue with those units, suspect vapor lock first, especially since it happens after the unit heats up, and goes away as the unit cools down.

 

[TwinOaks9]

When the tractor was new I had a problem with the gas cap not venting, that has been corrected and I check that when this occurs and that is not the problem. I also replaced the vacuum fuel pump with an electric one (runs better, starts better) and when this occurs if you take the fuel line off the at the carburetor there is plenty of fuel, so if it was vapor lock related I should not have any fuel at the carburetor, correct? Just a note, this occurred before I replaced the fuel pump, I thought perhaps the fuel pump was the problem.

 

[MossRoad]

Could be something in the bottom of the fuel tank plugging line? We've seen that before, too.

 

[cqaigy2]

Could be something in the bottom of the fuel tank plugging line? We've seen that before, too.

That was my problem. White sealer in the connector on the bottom of the tank. I could hardly see it, as it matched the tank color so well. I pulled the tank, removed fuel line and blew compressed air back toward the tank. Then checked with wire etc. Washed the tank out, rinsing well. Let it dry and have not had a problem since.

 

[MuncyBob]

Sounds like vapor lock. At a minimum move the fuel line away from the exhaust if possible and insulate the line. Best solution to avoid future problems(I had a valve job done at 1k miles or so and most likely due to extreme heat) is do the mod involving replacing the PT muffler and adding another fan for the cage. Did wonders for me and reduced cage/engine temp considerably.

 

[TwinOaks9]

My issue is specifically heat related, plenty of fuel at the carburetor, so I purchased an auxiliary fan and would like to ask Farmall140 where he mounted his fan, side or back, and if is drawing air or blowing air across the engine?

Thanks!

 

[MuncyBob]

Side mounted. Originally was blowing in but I find that drawing out of the cage is much better. Also installed a thermostat to turn on at higher temps and remain on even after shutting down until below that temp. Here are some pics provided by former member Kent that helped me big time on this. I verified with an infrared thermometer that the heat n the cage was dramatically reduced. Sorry for the late reply on this...been busy around here.

https://www.tractorbynet.com/forums/private.php?do=showpm&pmid=914442

 

[MossRoad]

link doesn't work.

 

[cqaigy2]

Invalid Private Message specified. If you followed a valid link, please notify the administrator

 

[MuncyBob]

Sorry 'bout that. It's an old PM and mostly pics. In any case, I also installed a Robin muffler and some high temp tubing to eliminate the 90 degree curve in the manifold. I think I may have some of that tubing in my garage somewhere if you can use it.