1988 310-8 Carb

[tunahead72 2,484]

This is the same 1988 310-8 I posted about a week or so ago, with an overcharging issue, this time we're looking at the carb (Kohler Magnum M10 engine, spec. 461521)…

 

The engine ran okay last fall, but now it won't start and run on its own.  It has spark, and fuel is being pumped into the carb, but it won't run.  I sprayed some carb cleaner into the carb throat while my daughter cranked it over, and it will start and run briefly until the cleaner runs out.  I took the carb off, and I plan to clean and rebuild it, and replace all the fuel lines and filter, and probably the shutoff and grommet at the tank as well.

 

Here's an amusing little photo of the carb area before I started taking things apart.  Notice the custom linkage, which was very loose and sloppy.  The tractor wouldn't idle at all, I had to keep the RPM's up to keep it running:

 

 

The carb is a Kohler #26 fully adjustable unit, and may be original.  I've taken it almost completely apart, including removing the throttle shaft and plate.  It actually doesn't look too bad, except for a couple of things:

 

1.     The throttle shaft shows signs of being abused.  It was very loose in the body of the carb, and the bore in the carb is noticeably egg-shaped.  The screw that you see in the photo above is holding the flat part of the lever to the top part of the shaft.  Once I removed that screw, I found that the tab at the very top of the shaft is not connected to the lever, and the top section of the lever is bent.  The flat part of the shaft itself, where the plate sits, also has a bend, like something was exerting a lot of pressure front-to-back.  Here's some more photos:

 

 

 

 

2.     The inlet needle and seat don't look original to me.  I've only had a few of these carbs apart, but all of their needles and seats look identical to me.  These look very different:

 

 

I plan to give this carb a thorough cleaning and rebuild, with bushings for the throttle shaft and correct new parts, but I'm not sure what to do about the throttle shaft itself.

 

I've seen genuine new Kohler throttle shaft repair kits that include a new shaft, bushing, screws, etc., but they're pricey, like $40-$70 expensive.  And I've seen an instruction sheet (TT321-A) for that kit, which indicates that you have to remove the old lever (which doesn't look like mine in their photos), and install it on to the new shaft with a single very small screw.  Have any of you guys done this, or is there a better way to connect the throttle lever to the top of the shaft?  I don't weld, and I haven't soldered anything in literally decades, but would that work, or maybe J-B Weld?

 

Another option…  Does anybody here have a complete throttle shaft assembly, with the lever already connected, in good shape, that would work on this tractor?  I'm also open to the idea of buying a good used Kohler carb if anybody has one they can sell to me.  I'll put an ad in the classifieds if I have to.

 

Any thoughts?

 

[ebinmaine 69,687]

20 minutes ago, tunahead72 said:

soldered anything in literally decades, but would that work, or maybe J-B Weld?

 

Another option…  Does anybody here have a complete throttle shaft assembly, with the lever already connected, in good shape, that would work on this tractor?  I'm also open to the idea of buying a good used Kohler carb

 

I have an appreciation for the fact that you're doing your best and in fact a LOT more than most folks would consider reasonable to save a good carb body. 

Me and the new replacement carbs are just not friendly.  

 

See the bold above.  

 

I don't think soldering is the way to go. You can't really get the metal hot enough to make it work right. 

Brazing... Is a possibility.  

 

I do believe J. B. Weld would be fine. 

 

 

That said, Lincoln at A to Z Tractor in PA would very likely have the parts you need.  

 

 

Well done.  

 

 

[squonk 41,894]

Tuna, I have a carb here I'm not fond of. I'll get you a pic of it and see if you can make use of it 

[squonk 41,894]

Older style with clamp style throttle arm 

 

 

 

[tunahead72 2,484]

3 hours ago, ebinmaine said:

I have an appreciation for the fact that you're doing your best and in fact a LOT more than most folks would consider reasonable to save a good carb body.

 

Thanks Eric, I appreciate that.  I'm aware that I tend to over-analyze these things.  It feels like a sickness sometimes, but I'd rather spend my time and energy digging into one of these things and learning what makes it tick, than having to try to understand a cheaply made imitation that I know right from the start isn't going to give me the long-term satisfaction I'm looking for.

 

I don't think soldering is the way to go. You can't really get the metal hot enough to make it work right. 

Brazing... Is a possibility.

I do believe J. B. Weld would be fine.

 

Good point about the soldering, I hadn't thought of that.  The more I think about it, the more I think J-B Weld might be a good choice, as long as I'm careful about it.

 

That said, Lincoln at A to Z Tractor in PA would very likely have the parts you need.

 

Thanks for the reminder about Lincoln, I always learn something useful from him when I talk to him.

 

[tunahead72 2,484]

4 hours ago, squonk said:

Tuna, I have a carb here I'm not fond of. I'll get you a pic of it and see if you can make use of it 

 

3 hours ago, squonk said:

Older style with clamp style throttle arm

 

That's a maybe, Mike.  What kind of engine is that from?  And why aren't you "fond of" it?

 

[squonk 41,894]

It's off an older 12 horse. Inside stunk bad of old gas

[tunahead72 2,484]

So at the very least it needs a good cleaning, or two -- good thing I don't have a great sense of smell.  I'll think about it and let you know.

 

[tunahead72 2,484]

I finished cleaning and rebuilding the carb on this tractor.  It's pretty much ready to install, but I'm going to remove and clean the breather assembly, and adjust the valves while I have the carb off.  I've already removed, cleaned and flattened the cylinder head, so it's ready to go with a new gasket.

 

The carb cleaning and rebuild went pretty smoothly.  I used a standard Kohler 25 757 01 kit, which included the inlet needle and seat that I'm used to seeing.

 

I did repair the throttle shaft and lever with J-B Weld, and installed a couple of the Ace/Hillman 58087 bronze bushings to take up the slop in the bore.  The shaft is much tighter in the bore now, and it seems to be operating as it should.  I'm looking forward to getting it back on the tractor to see how it works in the real world.

 

When I did the throttle shaft/lever repair, I inserted a couple of short wooden dowels through the throttle and choke openings to "lock" the throttle shaft and plate in the fully open position while I applied the J-B Weld.  That looked something like this:

 

 

 

And here's what it looks like now, ready to install:

 

[ebinmaine 69,687]

Excellent work on that 👍