Low RPM

[1973Auto 83]

Hello all and happy new year! Thism may be a little long , so please bear with me. I csn not get the RPM's up on My 12hp k301. When it's in idle or out of gear , the rpm's go up , but as soon as I put it in gear or get a load on it , they go down to about halfway. I've turned all the screws on the carburetor can't get the  RPM 's up. So my question is , before I start twisting tearing and swearing , could it be the carburetor the fuel pump or the rings. It does burn oil about 4-5 or ounces every hour or so when i'm plowing.  The plug pic is after 1-2 hours of plowing. It still plows ok but no speed.  The ring job is not happening this winter, so a rebuild carb and fuel pump is my option. Need advice on what direction or if there us something else.  Thanks all!!!

[Racinbob 12,484]

Start by downloading this manual. Go to section 6 and set your governor up properly. Set the carb adjusting screws to the factory settings.  

 

Engine Kohler K-Series SM TP-2379.pdf - Kohler - RedSquare Wheel Horse Forum

[rmaynard 16,761]

I would be inclined to look at your governor to see if it is hooked up and functioning correctly. Having said that, a good carburetor cleaning is always good.

[Achto 30,351]

A bad condenser can cause issue at high RPMs

[lynnmor 8,307]

Since the RPM only drops when in gear you should verify that the belt, pulley and everything is turning freely.

[953 nut 63,390]

1 hour ago, 1973Auto said:

I csn not get the RPM's up on My 12hp k301. When it's in idle or out of gear , the rpm's go up , but as soon as I put it in gear or get a load on it , they go down to about halfway. I've turned all the screws on the carburetor can't get the  RPM 's up.

Is this an aftermarket Chinese Carburetor?  If so do you have the factory carb. that was on the engine?

The Chineseium Carburetors are sold as fitting 10, 12, 14, and 16 HP engines. They do fit but will not operate properly on any engine in many cases.

The one and only Chineseium carb. I ever bought had the 26mm body for a 10 or 12 HP engine but had a main jet for a 14 or 16 HP engine. There was no way of adjusting it to make it perform properly.

[1973Auto 83]

1 hour ago, lynnmor said:

Since the RPM only drops when in gear you should verify that the belt, pulley and everything is turning freely.

Belts are good, I plow fine just with low RPM

[1973Auto 83]

1 hour ago, 953 nut said:

Is this an aftermarket Chinese Carburetor?  If so do you have the factory carb. that was on the engine?

The Chineseium Carburetors are sold as fitting 10, 12, 14, and 16 HP engines. They do fit but will not operate properly on any engine in many cases.

The one and only Chineseium carb. I ever bought had the 26mm body for a 10 or 12 HP engine but had a main jet for a 14 or 16 HP engine. There was no way of adjusting it to make it perform properly.

Not chinese carb. Original 

[sqrlgtr 1,616]

Have you replaced plug and seen how it runs after. I have fouled plugs before and sometimes they would just never run right again and the next one you could clean and was good to go. Just sumin easy to try before you get to deep.

[Ed Kennell 43,954]

Check the fuel supply to the carb. Pull the spark plug wire, then   pull the fuel line at the carb., hold it in a can and crank the engine.  You should see a strong spurting fuel.

 

You might also try running with the gas cap loosened...clogged vent hole maybe.

Edited 3 hours ago by Ed Kennell

[oliver2-44 11,105]

1 hour ago, sqrlgtr said:

Have you replaced plug and seen how it runs after. I have fouled plugs before and sometimes they would just never run right again and the next one you could clean and was good to go. Just sumin easy to try before you get to deep.

Definitely start with a clean plug before any other adjustments. 
I have a Case 180 with a very worn engine. I just take it to shows and it runs amazingly well for about 2 hours. Then won’t even start. Clean plug and it off and running. I have a little Harbor Fright plug blaster that helps keep several clean one available. 

[953 nut 63,390]

4 hours ago, 1973Auto said:

I plow fine just with low RPM   

4 hours ago, 1973Auto said:

Not chinese carb. Original 

 

The engine may be able to provide enough power to push the snow but a splash lubricated should NEVER be run at low RPMs except at shutdown.

If an original carburetor is unable to be adjusted it has one or more small openings plugged. the main needle has several small passages that must be clear for throttle good response. Check out this thread from @T-Mo, also @ebinmaine has some good threads on carbs.

 

 

[kpinnc 16,360]

7 hours ago, 1973Auto said:

The plug pic is after 1-2 hours of plowing.

 

There are several good options mentioned here, and hopefully one of them gets you through winter. That being said, it would be a good idea to do a leak down test. Compression checkers won't work due to your engine having internal compression release. 

 

Just from how that plug looks, you may have some blowby that is robbing torque. Might need a rebuild, but could also be leaky valves. 

[Ed Kennell 43,954]

Cleaning the breather may help the oil consumption.    

[sqrlgtr 1,616]

1 hour ago, 953 nut said:

splash lubricated should NEVER be run at low RPMs except at shutdown.

need that air circulating also might not be as important in middle of winter but....

[1973Auto 83]

6 hours ago, sqrlgtr said:

Have you replaced plug and seen how it runs after. I have fouled plugs before and sometimes they would just never run right again and the next one you could clean and was good to go. Just sumin easy to try before you get to deep.

Plug is new, clean it before each use.  Have 4 more new ones on deck