K301 Throttle Issue

[BrianX128 107]

I guess this is best in engines. I just got done swapping in this K301 onto the old C161 frame I had sitting around after stealing it's engine for my wife's mower. Everything works great, but I cannot get the throttle adjusted properly.

 

I have the wire from the throttle into the middle larger hole of the linkage on the engine. I tried various holes on the governor arm and for the spring on the throttle side, and the best I can get is for it to be at wide open throttle at 3200rpm, but the full travel of the throttle to idle only gets me down to 2100 rpm, and the throttle is backwards. Both my magnum 14 and K341 I have idle at 1500 ish with the same gauge running off of the pulses from the stator. I can tell this isn't low enough of an idle, and I can manually move the throttle against the idle screw and it will idle down to 1500. Does the throttle cable not have as long of a travel on C161's? I know where the throttle mounted is slightly different and was a straight through hole that a set screw holds the cable on the K341, but that's not what the K301 has. If I move the cables on the governor arm I can get the idle right, but then I can't get up to the right rpm at wide open.

 

Here's a video, unfortunately I didn't show the linkage but I can post a picture when I get home from work. I'm just glad the cobbled together spare parts made a working mower. Sure it has the wrong air cleaner, wrong engine mount, extra idler for the drive belt, giant spare facet fuel pump, duct tape seat, and it just looks kinda bad.. but hey it's the "7th mower" and was basically free, so I'm happy with it lol.

 

 

[wallfish 17,632]

A pic of the linkage would certainly help so please post when you get a chance

[953 nut 58,382]

If you would show us a couple photos of the way your throttle is hooked up at the engine we may be able to help.

[BrianX128 107]

 

 

Not the best picture sorry hard to get in there. That's the second fuel filter I need to remove btw.. didn't have anymore hose in stock when plumbing my electric pump so double filtering it. I can say nothing is stopping the throttle from moving its just like it doesnt have enough travel or tension from the governor. Well it does to wide open, it doesn't lose enough for idle.

Edited July 2, 2020 by BrianX128

[BrianX128 107]

So I tried some more things and was able to get the rpm range from 2100 to 3400 now, but still can't get it below 2100. I moved the throttle cable from the big hole in the middle to the bottom hole so it has more travel. If I screw in the screw in the second picture I can get down to 1600 idle, but then I can only get up to 3000 rpm wide open. If I move the governor side of the spring down I can higher rpm but it still idles high, and the reverse happens if I move it up. Just can't get a long enough "travel" no matter where I put it.

[Tuneup 1,441]

Interesting tach - they are manufactured for cars so check the setting # of cylinders. Are you sure of accuracy? How is it set and can you find another source of RPM to check it against? Just curious since a 4 cylinder setting would read 1/4 on a Kohler, right?. Let's see: 2 coil pulses per rev on a 4 banger and 1/2 pulse per rev on a K series - ouch! head hurts. I'd think it would need a multiplier in there somewhere. They are nice little devices and I might be patient enough to wait for shipping from India and to build a multiplier...

 

As for the governor setting, at low setting, is the throttle being returned to the idle set screw with engine off? I don't have to ask if you forced the throttle by hand to the set screw to ensure that it will idle where you want it, pre-governor check. Yadda, yadda - Friday!!!

[BrianX128 107]

Actually that tach reads from stator pulses believe it or not. It has 12, 16, and 18 pulse settings. Since our flywheels are 6 magnets and 3 poles, or 18 pulses. It has 3 throw switches on the back to pick if you want those, or it can go to 1, 2 or 4 cylinder mode as well. 

 

Interestingly enough when you mention the throttle, with the engine off it does not return to the idle set screw. I didn't realize any of them do? I thought they all had tension until the engine idle pulls it to the set screw? I never paid attention to my K341 or my Magnum 14 which will read 1700 idle and 3500 wide open. I did go through the counter clockwise governor setting procedure on this engine, but even after that when at idle the throttle is still being held half open by tension. I have forced the throttle to the idle set screw while running and it works fine there.

[Tuneup 1,441]

Thanks for the news on the tach. I already had a pulse multiplier in my head - anything to solder a transistor. My '80 C-125's throttle is forced hard against the stop, at least with engine off. Happy to take a pic of the governor linkage if you need it.

[BrianX128 107]

Does yours have the "arm" that links to the throttle on the flywheel cover to pivot on? This is the only one I have that doesn't have that piece and has that strange little set screw you see in the second picture I posted. I'm wondering if this version just isn't compatible with that type of throttle. Come to think of it, I have no clue where this K301 really "lived" before I got it. Previous owner got it for a golf cart not realizing the shaft size was 1 1/8" not 1" and couldn't do what he wanted with it. It also had a gas tank mounted on top of it and 3 studs in the head instead of bolts for the tank to mount to, and the decal was on that plate like it was original. Not sure what that means it would have been on originally, but it couldn't have been on a horse, you could have never shut the hood?

[Tuneup 1,441]

Hi Brian - sorry so long to answer. Hopefully, you'll see this.

 

My 125 has that same linkage. The throttle arm closes enough at low throttle to actually push the spring against the governor to force the throttle closed. The throttle cable on mine connects to the blower housing. The cable is connected at the top of the lever.

Adjusting for low throttle - pushing the cable through the clamp until the governor spring forces the throttle fully closed. If you can't get to 3600 on high afterwards, adjust the throttle cable lever spring location to provide for more pull. Make sure first that the high thottle stop isn't cutting it short. Once to 3600, move that stop to end further travel. At least that is my adjustment method.