My Tractor Forum banner

1 - 8 of 8 Posts

·
Registered
Joined
·
26 Posts
Discussion Starter #1
This is a Craftsman II riding mower. 18 HP.

It starts up and run. However, when I slide the throttle control up or down, nothing changes.

Look under the engine, I see the cable pulls a slanted disk. There is a pin goes against this disk. When the disk moves/rotates, the pin moves in and out by a spring. Without the engine running, this appears to work although not very good (it doesn't move all the way in or out).
However, when the engine runs, the pin appears to be at a slowest throttle position. The engine seems to run at normal speed. Does this means I need to adjust some default on the carburetor?
The if I slide the control to high speed, the pin stays the same location. I use my hand to push the pin, and the engine screams (go much faster). My feeling is that it should not go that high. The default should be lower. And when I move the throttle to fast position, the engine should run at the current level.

Anyway, the pin pushes against my hand real hard when I push it; and the pin goes back to the old position. I believe this is the governor's work.

So, please tell me what do I need to do to fix this? Thanks.
 

·
Registered
Joined
·
39 Posts
Most throttle cables I have dealt with have a center shaft/wire running through the center sheath that looks like a long spring. You need to make note of where the throttle end connects to the governor linkage. Then take that hole piece out and see if its not kinked or binding somewhere. Soak it in WD-40 and make sure the center wire slides independently of the sheath. Then reassemble. Should be an easy fix. You can also purchase the throttle cable and replace the whole thing if need be.
 

·
Collector of many tractors
Joined
·
15,270 Posts
Sounds like the thing you call the pin is the end of the cable... The end of the cable needs hooked into the rotating throttle shaft...
 

·
Retired Aug.31 2007
Joined
·
7,473 Posts
Sounds like the hold down clamp for the throttle cable is missing or loose.
 

·
Registered
Joined
·
26 Posts
Discussion Starter #5
I am very sure the cable is working fine. I did check and when sliding the control nob back and forth, the other end of the cable moves back and forth easily. The cable attachment is also very tight.
 

·
Registered
Joined
·
4 Posts
i have pretty much the same problem, except mine sounds like its running WAY too fast, and i cant make it change speeds. this is my first twin cylinder tractor,(exactly the same as OP) but the single cylinder that i have sounds way quieter, leading me to think itsrunning too high. i cant figure out how the throttle works, nor can i find any explanations... but like the OP, my cable definatly works, and moves all the other little things, except for the part attached to the carb and the one after that...
 

·
Registered
Joined
·
26 Posts
Discussion Starter #8
i have pretty much the same problem, except mine sounds like its running WAY too fast, and i cant make it change speeds. this is my first twin cylinder tractor,(exactly the same as OP) but the single cylinder that i have sounds way quieter, leading me to think itsrunning too high. i cant figure out how the throttle works, nor can i find any explanations... but like the OP, my cable definatly works, and moves all the other little things, except for the part attached to the carb and the one after that...
I have resolved my problem. It appears to have a same problem as you described. I adjusted the 2 screws for teh carburetor. The one that goes inside the carb, I turned all the way in, then back out 1 and 1/2 turns. The other screw which stops a little metal plate, I turn it out all the way. Then I adjust the 1st screw to make the engine sound good, but low speed. After that, the throttle control does affect the engine speed as I slide it up and down.
 
1 - 8 of 8 Posts
Top