K301 engine speed setting

powerpooch · #1 05-15-2016, 12:40 PM

Hi,
On my 1250, the K301 engine was always running a little slower than it should be. I know that The 1250 is a QL, and uses the K301, which puts the engine RPMs at 3,400 instead of 3,600 (sorry if I'm a little off, with moving I have to rely on memory unless I didn't unpack the service manuals yet).

I replaced the governor spring recently, adjust the governor arm & shaft, and adjusted the throttle cable.

For the arm and shaft, I moved the shaft counter clockwise and the arm so the carburetor was completely open.

I followed this post for setting the springs: http://www.onlycubcadets.net/forum/s...456#post153456

Placing the throttle at full speed, the engine is defiantly spinning too quickly, and I lose any governor effects. The engine stops responding to changes in demand.
I believe the governor still works because if I run the engine without the spring in place, and try to change the speed by hand, I do feel the shaft pushing back to lower the speed.

I haven't used the engine passed a safe speed for more than a few seconds. Pretty much as soon as it sounded too fast, I lowered the throttle down.

I don't have any form of tachometer for this engine, and getting one seems a bit of a challenge in my area unless I order online.

Bob95065 · #2 05-15-2016, 01:41 PM

Quote:

Originally Posted by powerpooch

Hi,
On my 1250, the K301 engine was always running a little slower than it should be. I know that The 1250 is a QL, and uses the K301, which puts the engine RPMs at 3,400 instead of 3,600 (sorry if I'm a little off, with moving I have to rely on memory unless I didn't unpack the service manuals yet).

I replaced the governor spring recently, adjust the governor arm & shaft, and adjusted the throttle cable.

For the arm and shaft, I moved the shaft counter clockwise and the arm so the carburetor was completely open.

I followed this post for setting the springs: http://www.onlycubcadets.net/forum/s...456#post153456

Placing the throttle at full speed, the engine is defiantly spinning too quickly, and I lose any governor effects. The engine stops responding to changes in demand.
I believe the governor still works because if I run the engine without the spring in place, and try to change the speed by hand, I do feel the shaft pushing back to lower the speed.

I haven't used the engine passed a safe speed for more than a few seconds. Pretty much as soon as it sounded too fast, I lowered the throttle down.

I don't have any form of tachometer for this engine, and getting one seems a bit of a challenge in my area unless I order online.

I have a 1000 and a 1450. I used these manulas:

Engine service:
http://www.onlycubcadets.net/forum/s...ead.php?t=4646

Check out page 6.26 for governor adjustment. 6.29 lists high speed at 3600RPM no load. That's where I set my tractors.

Tractor service:
http://www.onlycubcadets.net/forum/s...ead.php?t=4644

I bought this tachometer: http://www.amazon.com/AGPtek%C2%AE-P...rds=tachometer

It seems to work well.

Bob

J-Mech · #3 05-15-2016, 02:22 PM

3600 RPM is the correct speed for all motors. I set mine to run 3800. I suggest at least setting it to run 3600 with the deck engaged.

Unless you have checked it with a tachometer, I wouldn't trust you ear to tell you the engine speed. Unless your highly trained, most people can't even come close to guessing RPM.

powerpooch · #4 05-17-2016, 01:42 PM

Guess I will have to get the tachometer online. I've checked a few stores in my area and non seem to carry them.

I will post back later, after I get the tach and play with it a little more.

powerpooch · #5 05-22-2016, 04:21 PM

Just got the tachometer yesterday.
Played with it and the engine is coming in at 3,200 ish
I just need to get it slightly higher and it should be good now. I am pretty sure by sound that it was going over 3,800 rpm but with so many projects and time between the last time the 1250 was running, its hard to be 100% positive.

I found the service manuals I have. Slightly buried but I did find it. I found what I was thinking about. The K301 in no QL tractors run at 3,800 and the QL run at 3,600 without load and with load its 200 rpm less for each.

RPM chart from March 1975

kuleinc · #6 05-24-2016, 12:14 AM

How do you get it higher? My 123 runs a little slow, and I adjust the governor and its either too high or too slow...

mortten · #7 05-24-2016, 08:58 AM

Adjusting the governor doesn't adjust the speed. On a 123 there is an angle bracket where the throttle cable attaches to the engine. You loose. The pivot bolt and move the bracket clockwise to increase top speed, counter clockwise to decrease top speed.

powerpooch · #8 05-24-2016, 10:13 AM

kuleinc - Bob posted the manual and page number to find the info you need.

I changed everything on mine. I shortened the cable, completely re-adjusted the cable, reset the governor, etc. Kind of a spring overhaul for me.

What rpm is your 123 running at now?
Its Fairly easy to adjust the speed when you aren't too cheap to get the tachometer. Took me about 20 minutes, but I was fiddling with everything else also.
It sounds great and mowed the over grown grass like it wasn't even there.

Quote:

Originally Posted by Bob95065

I have a 1000 and a 1450. I used these manulas:

Engine service:
http://www.onlycubcadets.net/forum/s...ead.php?t=4646

Check out page 6.26 for governor adjustment. 6.29 lists high speed at 3600RPM no load. That's where I set my tractors.

Tractor service:
http://www.onlycubcadets.net/forum/s...ead.php?t=4644

I bought this tachometer: http://www.amazon.com/AGPtek%C2%AE-P...rds=tachometer

It seems to work well.

Bob

kuleinc · #9 05-24-2016, 10:23 AM

Somehow I missed bobs post? I have a tach in my timing light, my idle was at 2200

I set it to 1000, much quieter now, it stumbles a bit if I throttle to max quickly but doesn't die. I can't recall my max rpm exactly but I think it was in the 3400 rpm range. I did have that bracket off when I rebuilt carb, so I must have not put it back quite right. Sounds like an easy fix. My lawn needs a mow every five days and I'm lucky if I can do it on day 7, so I need all the blade speed I can get! I just sharpened the blades for the first time, that was interesting. Thanks for the help and pointers, I spent about 45 mins on it before I had to go eat dinner and gave up.

powerpooch · #10 05-24-2016, 12:01 PM

I must ask, why do the quiet lines tractors want a minimal idle of 1800 while ever other tractor wants 1000? I know my 1250 was set just below 1800 but it sounds fine.

I know what you mean about the lawn kuleinc, if I'm just waiting for the middle of summer where the grass grows faster than the mower can mow the lawn, and anyone has enough time to mow it. As it is I was already late to get to the first cut, and the grass already looks so bad. Summer came too quickly.

My manual only lists the 128, 129, 1200 and 1250 the K301 engine and it looks like you should be running around max of 3800 rpm with no load and at 3600 rpm with full load. The 1200 and 1250 want 3600 and 3400 rpm.