Possibly running rich

[Asphaltcowboy7]

Hello all,
Just bought a Kubota TG 1860G from a private seller. He stated the carburetor was replaced. While running under normal operations the exhaust is burning my eyes. It seems like there's too much fuel & the tractor may be running rich. I looked up the diagram & see there's an internal jet. I'm guessing these are preset when assembled. Aside of taking a new carburetor apart to check adjustment I'm not sure how you'd determine the adjustment or to lean out the mixture. Tractor runs ok , doesn't stall but surges just a little bit intermittently idled up. Stumped here & any thoughts/ help on this matter would be greatly appreciated. Thank you

 

[lynnmor]

If the replacement carburetor was a cheap Chinese one, try to get the original and service it. The junk coming out of China can cause problems.

 

[85Hokie]

what do the plugs look like?

 

[lmichael]

Engines can throw off some pretty acrid fumes when not running at proper mixture. My experience is when they run too lean it's even worse than too rich. But, in all honesty I have noticed since I got my diesel Kubota when I come in from yard work I no longer smell like exhaust as I did with my previous machines (Honda 4514, Simplicity Sovereign and Allis Chalmers B10 with new(er) 16hp Briggs single)
All running in perfect tune with OEM carbs. Gasoline just has a far more acrid "aroma" than diesel

 

[Asphaltcowboy7]

I believe everything was serviced prior to the sale, plus should've been done but I'll definitely check. Thank you everyone for your help!

 

[leveraddict]

I would just up the idle and turn the adj screw on the carb untill it smooths out. Give it a try could be thats all it needs!

 

[lugbolt]

smell means nothing. You can't go by that no more. Today's fuel is oxygenated garbage that is designed specifically for CARS (they all have catalyzers and EFI) and not lawn mowers, and certainly not old lawn mowers with carburetors. Old stuff and stuff that ain't got cats will all stink, even running at it's best mixture they still stink. If you don't like it and the machine is running properly (no fouled spark plugs), you can get yourself a bottle of fuel fragrance which helps reduce the fume. Pick your "flavor"...grape, bubblegum, watermelon, pot, chocolate whatever. I think there's like 23 different ones.

 

[Asphaltcowboy7]

I would just up the idle and turn the adj screw on the carb untill it smooths out. Give it a try could be thats all it needs!

Ok thank you! Where is the adjustment screw located?

 

[lmichael]

I would not make any "adjustments" until you ascertain that something is actually not "right". That it smells badly doesn't necessarily mean something is "wrong".

 

[GeoHorn]

If the replacement carburetor was a cheap Chinese one, try to get the original and service it. The junk coming out of China can cause problems.

I’ve replaced three OEM carbs with Chinese “junk” ..(thought that was a type of BOAT..??)...

...and I’ve had nothing but SUCCESS with them. Modern autogas is what is JUNK! It eats carbs that it sits in for more than a couple weeks. The Honda generator carb was destroyed. Honda wanted $180 for the replacement. The copy-cat-china-carb was $19 and now, 2 years later, is still working perfectly. (I don’t let it sit with junk autogas in it...I run it dry and then open the bowl-drain.)

The pressure-washer Briggs & Stratton carb also died. B&S wanted $35.... china wanted $18. Works perfectly.

The lawn-tractor B&S carb died. Chin-easy was $20 and was bolt-on-simple and works great.

One thing the chinese was always known-for and did great: Copy-Cat... and they do it well.
(They are finally even learning to copy Capitalism.... now if they’d only learn insurrection...

 

[kubotafreak]

I’ve replaced three OEM carbs with Chinese “junk” ..(thought that was a type of BOAT..??)...

...and I’ve had nothing but SUCCESS with them. Modern autogas is what is JUNK! It eats carbs that it sits in for more than a couple weeks. The Honda generator carb was destroyed. Honda wanted $180 for the replacement. The copy-cat-china-carb was $19 and now, 2 years later, is still working perfectly. (I don’t let it sit with junk autogas in it...I run it dry and then open the bowl-drain.)

The pressure-washer Briggs & Stratton carb also died. B&S wanted $35.... china wanted $18. Works perfectly.

The lawn-tractor B&S carb died. Chin-easy was $20 and was bolt-on-simple and works great.

One thing the chinese was always known-for and did great: Copy-Cat... and they do it well.
(They are finally even learning to copy Capitalism.... now if they’d only learn insurrection...

I have had similar experiences with the knockoffs used on my less than oem fleet. Main difference I have seen is lack of adjustability, or serviceability of a non oem Mikuni.

 

[Asphaltcowboy7]

I would not make any "adjustments" until you ascertain that something is actually not "right". That it smells badly doesn't necessarily mean something is "wrong".

OK, thank you very much for your feedback.

 

[kubotafreak]

Kawasaki two cylinder? I have dealt with this gas engine a bunch. Most common issue on them for surging is the idle jets. The air pilot that is not covered with the choke plate, and the idle pilot on the top left of carb. The jets need to be poked with a wire the size of the passage. They will appear clear, but the thin crusty buildup makes all the difference. The idle fuel on the top has a really small orifice vertically that commonly clogs.

 

[Asphaltcowboy7]

Kawasaki two cylinder? I have dealt with this gas engine a bunch. Most common issue on them for surging is the idle jets. The air pilot that is not covered with the choke plate, and the idle pilot on the top left of carb. The jets need to be poked with a wire the size of the passage. They will appear clear, but the thin crusty buildup makes all the difference. The idle fuel on the top has a really small orifice vertically that commonly clogs.

Is this the internal jet or something I can get to from outside the carburetor?
Thank you for your help!

 

[kubotafreak]

The single bore jet is in the throat of the carb. The idle pilot is on the top, and requires the carb be removed.

Should require the hood be removed. From inside the fan housing, you can access the intake elbow bolt/nut. Then the front of the carb nuts. The gray fan shroud may be a bit different, at least this is how the same engine in the John deere is made.

 

[Asphaltcowboy7]

The single bore jet is in the throat of the carb. The idle pilot is on the top, and requires the carb be removed.

Should require the hood be removed. From inside the fan housing, you can access the intake elbow bolt/nut. Then the front of the carb nuts. The gray fan shroud may be a bit different, at least this is how the same engine in the John deere is made.

Thank you very much for your help!

 

[lugbolt]

actually I have to back up on what I said

many times in the past manufacturers tried to get engines to run at or very close to stoich (ideal air/fuel mixture) with no load on the engine, yet it would richen up a little as load was applied. Stoich for 100% gasoline is 14.7:1.

We no longer have pure 100% gas, it's almost all E10 now, and if you find "non ethanol" it's probably not 0% ethanol (more like 3%). E10 is fine, run it, and don't let it sit in the tank/carb and you'll never have a problem. The issues with E10 is that it stinks anyway (with no cats) and secondly E10 fuel has an ideal a/f of 14.06 which is a little richer than E0, which is 14.7

so with the carb, you're going to be close to 14.7:1 with E10 which is a little on the LEAN side, though not enough to cause trouble. It will, however, burn your eyes. Even at 14.06:1, it's gonna burn your eyes. That's a characteristic of the fuel, the exhaust system, and many other things that you really don't have much control over.

So...as I said, if it's running ok, and not fouling spark plugs, just run it and don't try to fix a problem that doesn't exist. Even slightly lean won't hurt it. You'll have to be surging and pinging under a load to make any problems happen. One of the reasons I say this is because taking the carb off of one of these things is a pain in the backside. So if you can avoid it, do.

The only issues I've really had out of those engines is water pumps and fuel pumps. Water pump is on the bottom of the engine, they will wear out and leak water out of the weep hole OR they'll mix water and oil. The other is the fuel pump and that can be a big issue. The pump has a diaphragm inside of it and it will over time wear out and begin to leak. The leaking fuel runs out of a weep hole, which is directly on top of the muffler. It can/will catch fire if it leaks. The new fuel pumps have a hose nipple and a hose that you route down the side of the frame rail away from the muffler. I highly suggest replacing the fuel pump now even if it ain't leaking yet. Kawasaki actually had a recall on them at one point, but I think it expired (check to be sure). I have seen a few of these old 1760 and 1860 gassers catch fire and burn to the ground because of this issue, and one in particular that didn't completely burn up but it did a lot of damage and burned part of the owner's building where he had it stored.

 

[kubotafreak]

I second the mechanical fuel pump, same issues on the John Deere’s as well.