Small engine trouble

[dstig1]

I've got a Robin/Subaru engine on my splitter (Super Splitter) and it is now giving me trouble. I started it up a couple months back as it had sat a while and I wanted to make sure it was working. Started and ran great for 5 or 10 min. Flash forward a few weeks and I had a friend come over to help me split some wood. Now it wouldn't start. We were able to get it running with some carb cleaner shot in the intake, so it was clearly a fuel delivery problem. Finally decided the carb must be a bit plugged up, so i soak it in Seafoam for a week or two put it back together and it starts right up. But then the RPMs started to take off. I thought maybe I damaged the gaskets on the carb by taking it apart a billion times while messing with it, so I got new gaskets and put them in today (assuming an air leak after the carb, for example). Same problem - RPMs shoot way up and the governor does not seem to be doing anything. The throttle does almost nothing - it won't idle down at all. The governor linkage is moving perfectly easy and is connected correctly, but the linkage never moves on it's own now when the engine is running. I can move it by hand and it does what it is supposed to while running.

I'm at a loss. I have no idea how it could work perfectly and now come down with all these problems so soon after that. And I have no clue what might be wrong with it now. I haven't done much with small engines other than cleaning out a carb on occasion, so I am in the dark here. Anyone have any clues?

Thanks,
Dave

 

[teejk]

Sounds like you tried everything I can think of. I'm not familiar with that engine but I'm guessing it has a spring on the governor. Did you get that back into the same hole on the carb? Hard to believe that a few mm's on that arm can make a difference. The only other thing I can think of is whether you had previously adjusted the carb to keep it going. Now that you are starting clean, might have to go back and "undo" that.

 

[RobertBrown]

Price a new carburetor. You my find that it's less hassle to replace than to fix.
Hard to say what may help with no pictures of your engine.
You can probably get one from amazon delivered in a week or so.
get the serial and model numbers from the engine, search for part numbers the prices.

You may want to make sure run all the gas out of the tank after every use, and consider using a fuel additive/stabilizer.

 

[dstig1]

Thanks guys. I never did any carb adjustments (and I don't think there is much of anything I can adjust on it - they lock them down so much these days due to EPA). I could replace the carb, but that doesn't make sens to me at this point. Why would the governor not doing it's job depend on the carb? Now obviously this all started with the carb, but that one puzzles me. Carb is $115 from eReplacements.

Yes, I will be more diligent about draining gas. It was parked at a friends house for a few years as he was using it for the both of us (wood from my land, I block and haul to his place, he splits, we share wood) and he is not super careful about doing stuff like draining gas at the end of the season. As my house project gets more under control I have time to pay attention to this stuff...

Thanks,
Dave

 

[CCWKen]

A new carb won't fix an incorrectly assembled governor linkage. :confused3:

 

[teejk]

Thanks guys. I never did any carb adjustments (and I don't think there is much of anything I can adjust on it - they lock them down so much these days due to EPA). I could replace the carb, but that doesn't make sens to me at this point. Why would the governor not doing it's job depend on the carb? Now obviously this all started with the carb, but that one puzzles me. Carb is $115 from eReplacements.

Yes, I will be more diligent about draining gas. It was parked at a friends house for a few years as he was using it for the both of us (wood from my land, I block and haul to his place, he splits, we share wood) and he is not super careful about doing stuff like draining gas at the end of the season. As my house project gets more under control I have time to pay attention to this stuff...

Thanks,
Dave

Again I'm not familiar with that engine but know a bit about the Honda. On that one there are 4 holes on the carb arm to attach the governor spring to and it does make a difference (hard to believe...they are so close). Governors are usually either internal (weights) or external (fan). Try to find the service manual and see what it says about governor settings ("racing" etc.). It is possible that if it has been sitting idle for that long stuff just needs to operate for a while to get the cob-webs out.

 

[RobertBrown]

A new carb won't fix an incorrectly assembled governor linkage. :confused3:

A new carb will not fix incorrectly assembled anything. The carburetor provides the correct fuel/air mixture for proper combustion.

 

[3930dave]

Again I'm not familiar with that engine but know a bit about the Honda. On that one there are 4 holes on the carb arm to attach the governor spring to and it does make a difference (hard to believe...they are so close). Governors are usually either internal (weights) or external (fan). Try to find the service manual and see what it says about governor settings ("racing" etc.). It is possible that if it has been sitting idle for that long stuff just needs to operate for a while to get the cob-webs out.

If the governor is fan activated, check that the area is clear of leaves, mouse nests..... , if you haven't already OP.

Rgds, D.

 

[bcp]

Cartoon from the same day as post #1



Bruce

 

[dstig1]

I saw that one - love that cartoon!

This case is impossible to mis-assemble the governor. There are 2 holes in the throttle plate lever. One small one for the spring, one larger one for the linkage. No choices. The thing I don't see is the governor mechanism moving at all like it used to. Whether or not it is connected right (like I said, pretty much only one choice), I would expect to see it trying to adjust, even if incorrectly. It just isn't moving. I am always suspect when a new problem appears while fixing a different one, but i have personally seen it happen, so I know it can occur... I'll take a few pics, but it is a pretty common looking small engine design to my limited knowledge. And I don't know diddly about governors in small engines. The linkage goes to a bar that has a pivot on the far end that connects to something inside the engine. Haven't taken anything apart to look. No clue here.

Thanks again for the help.
-Dave

 

[Jim Nelson]

Those little Robin engines were used in a lot of golf/utility carts ,EZgo used a lot of them.If you google EZGo governor you will find some info. There are a couple of seemingly pretty good forums for those rigs with some experienced guys willing to help.

 

[Egon]

Will the governor linkage move when running? Can it be externally seized?

 

[Larry Caldwell]

I think you are looking at the wrong thing. The clue is that the throttle does almost nothing. The throttle is either disconnected or broken. Take the carb back apart and fix it.

 

[teejk]

I think you are looking at the wrong thing. The clue is that the throttle does almost nothing. The throttle is either disconnected or broken. Take the carb back apart and fix it.

I think he said earlier that manual operation of the governor rod made it work. I'm hardly an expert (or even much more than a novice) on small engines so I'll shut up after I explain my rather limited knowledge of governors. Either internal (weights) or external (that little flag that blows off the fan in the blower housing). Purpose of either is to keep the throttle closed. The balancing factor is the spring whose purpose is to keep the throttle wide open. They somehow work things out for perfect harmony. Not knowing anything about that engine but based on the OP's last post where he said there were only two holes on the arm, I wonder whether he got them mixed up. Over and out...

 

[CCWKen]

Typically, the governor spring will hold the throttle wide open when the engine is NOT running. When the engine IS running, flyweights (or fan sail) try to force the throttle closed. The faster the engine runs, the more force applied to close the throttle. As the engine slows down, less force is applied to counter act the governor and the throttle is allowed to open. This action is what allows the engine to compensate for different loads.

 

[dstig1]

As best i can tell Ken has it correct, at least for this motor. The throttle LEVER only really does one thing - add more spring pressure against the governor which helps keep the throttle plate open more. It does not directly act on the throttle plate in the carb. Throttle plate is fully open at rest, and the governor should pull it closed to modulate the speed. Or at least that seems to be how it looks to work from my manual tugging on it and looking it over. I'm guessing this one uses internal weights as the visible linkage stops at a pivot that goes into the main engine housing. I'll get some pics tomorrow as it will be rainy so I can't get anything else done...

Thanks for the tips on the EZGo forums, Jim. I'll start looking into those too.

More to come..

 

[GLyford]

I'd go back to basics, float, needle, jets, clean the heck out of it. I get a lot of engines running again just by freeing up the float and needle.

My local small engine guy says that he sees a lot of corrosion in diecast carbs where the zinc is basically being eaten away by the water/alcohol dissolved in the gas, sometimes to the point of being porous. If you see a lot of white residue in/on your carb, it might be time ahead to find another one.

 

[teejk]

I'd go back to basics, float, needle, jets, clean the heck out of it. I get a lot of engines running again just by freeing up the float and needle.

My local small engine guy says that he sees a lot of corrosion in diecast carbs where the zinc is basically being eaten away by the water/alcohol dissolved in the gas, sometimes to the point of being porous. If you see a lot of white residue in/on your carb, it might be time ahead to find another one.

Dunno...the problem is that the engine is "racing"...almost as if the governor weights are stuck. An old engine hand book mentioned that the governor spring will speed up an engine the closer the connection the pivot on the carb. OP said there are only 2 holes...

 

[GLyford]

If the float isn't seating and the carb is flooding, don't you think that might affect how it runs a little? Just spitballing anyway to see what sticks.

 

[teejk]

If the float isn't seating and the carb is flooding, don't you think that might affect how it runs a little? Just spitballing anyway to see what sticks.

I didn't see anything about flooding but maybe I missed it. Sounds like the governor spring has taken control and the counter balance (weights/vane) have waved the white flag. Seems as though the OP didn't replace the spring so I doubt it got stronger than OEM. OP did say that the machine sat idle for some time...guess it's plausible that internal weights would seize up and perhaps need to be run for awhile to free up...but like you I'm spit balling!