Erratic revving on barn find 1962 cc
 

any help will be greatly appreciated! when i open full throttle via the dash lever, the magneto lever on the engine that is attached to the butterfly on the carb by a thin rod keeps opening and closing revving erratically while the engine is running. I can only get full throttle if i manually hold the magneto lever and butterfly open. Any suggestions? I have tried playing with the 2 screws on the carb with no luck.

That lever is attached to the governor not the magneto. And I would check and clean the carb up before you go any farther. Also we need to know what engine you are dealing with in order to help you better.

finz68,
First welcome.
You could have several issues?
(Yea that leaver is attached to the carb at the top and attaches to the rod for the governor at the bottom)
We just had a similar problem with uncontrolled revving on our 102 and found that the butterfly plate on the carb had lost a screw and was not functioning as it should. I agree take off the carb, clean and check first.
Regards,
Chris

Thanks. I just rebuilt the carb but will take it off and check. the butterfly plate seems to have no resistance or spring of any kind.

its a Kolher with a Carter carb.

I told you the same thing in your post about the clutch.
"Go to the tech section and download the manual for your engine. The Magneto rod as you are calling it is the governor linkage. It sounds like you need to get the carb sorted out first before you damage something."
Do you expect one of us to come and fix your tractor and leave $20 on the counter?

sorry- first time in a forum like this and I didn't realize that I was taking advantage of all the knowledge out there. I will download the manual.

The best thing to do is to first download the manual and read it over good. Will give ya a good idea of what you're trying to fix.

Don't apologize for asking a question. We are here to help. It just helps us steer you in the right direction if you have a little knowledge of the area you're working on. I'm sure if one of us was close by, we'd stop over and help out a fellow cubber, no charge. :biggrin2: :beerchug:

Will do- much appreciated!

Is not about taking advantage of all the knowledge. It's about knowing and understanding what you are talking about so that you can explain correctly what is ailing your cub. Therefore the folks here can help you better. If you look at the carb adjust carb adjustment procedure for your particular engine that should get you close. Does your Original have the 7 hp engine in it?

Sounds to me like its running a bit on the lean side. Try turning the screw facing straight up off the top of the carb out maybe a quarter turn or so. It should make the surging a little better. Once you learn to "read " the spark plug and read good in the carb are of the manual you will be able to get it tuned in. Good luck and remember that manual can be your best friend

Thanks for the suggestion! You folks have been so helpful- I think that I became so obsessed with getting this dormant machine running on it's own power that I forgot the basics- research all that is available, create an educated game plan and THEN ask for the appropriate help when you hit a wall!

OK now we are getting somewhere. These things are pretty basic but carb and ignition can give you fits. The manual will help you understand how they function. If it has been sitting for a long time you almost certainly will need to rebuild the carb, then you can get it adjusted properly. If you post engine questions in the engine section you will find that we have some very talented guys that know these old engines inside out and should be able to get you running as good as new in short order. :beerchug:

Sorry if I jumped on your case yesterday. Good luck with your Cub.

Thanks bro- when you wrote, "do you want us to fix your tractor and drop $20 on the counter?", I was like, "whoa, I guess I pissed the moderator off pretty quickly, huh?" Delivery: 0, Point made: 1

Nope I didn’t get PO’d just that you had the same question posted in 2 threads. I don’t get PO’d that easy. But I have been known to bust on occasion. :biggrin2:

All comes down to the old saying

Take me fishing and feed me for the day or teach me to fish and feed me forever.

I know you said you cleaned the carb, so that's a plus. Did you clean out the rest of the fuel system too? Tank, filter/bowl, and gas line? I know for a fact it can clog a clean carb in a hurry if you didn't:biggrin2:

the entire fuel system: gas tank, lines and carb are rebuilt and cleaned. The governor control rod and attached throttle level freely surge when idling. I am combing through the manual right now.

Bad fuel, misadjusted carb, any problems in the fuel system can cause this. Something else to look at it how much "play" is in the linkage from the governor control lever to the carb. Any play in that rod that attaches the two, (I.E. the hole in the carb or governor is wore too big.) Any looseness in this linkage will cause it to surge.

Here's what I found out on my #127-12hp.;

I rebuilt the carb, new points, new spark plug, new head gasket, adjusted to specs (from the engine manual). & had that erratics reving from that governer rod at high idle. Broke the manual out on kohler engines, followed it to a T, & adjusted the arm to specs. Not good enough.:bash2:

I had to tinker around a bit but got it running right & now it purrs.:beer2:

I by no means am a mechanic, but by following the manual did help & helped me understand the mechanics of the engine a little more.

NIK,

Oh, new gas filter, line, oil change,

We love photos also.

Me too
 

I'll toss my hat into the "clean out the rest of the fuel system" (which is not much more than the tank, the sediment filter and petcock and the hoses/tubing) ring.

Fresh gas can work wonders too.

That carb is a remarkably simple affair. You could also remove the governor linkage and see if it's surging without the governor.

But I'd start with cleaning the fuel system. If the carb needed rebuilding, it does too!

Welcome!
John

Why would it surge without the governor? ...... I really don't think that would help or prove anything..... Unless something in the governor is broken. But I don't think we need to go there just yet.

Loose throttle shaft, insufficient fuel flow.....

Thanks. I will probably go through the carb and re-clean it. I bypassed the old fuel filter/lines just to get it started- I promised the original owner's daughter that as soon as I got it running on it's own power, I would drive it to her house. That promise was delivered Friday! She got very emotional- she recognized the sound of the motor from 2 blocks away.... very cool moment, very cool!

Yeah, I know. Of course the governor is making it surge. It should stop if you unhook it.......... What's the point. It doesn't prove anything........ unnecessary test UNLESS, we suspect a bad governor gear, flyweight, etc. Which at this point we do not.

With what all has been said about this problem so far, if this were my tractor the next thing I would do is set the points properly (not because I think that is the problem, but because (I think we can ALL agree that this little engine will not run right if the points are not set right) setting the points is much easier/faster than rebuilding a carb, plus doing this will eliminate the problem of "fiddling" back and forth between carb and points later.

Once you find out that setting the points is not the problem... Remove the carb, take it apart, blow all the passage-ways out and SOAK IT AND ALL OF ITS PARTS IN CARB CLEANER OVERNIGHT.

The next day, blow it out again and install a fresh kit, adjust the float, put it back together and put it back on the machine.

Then, when you find out that it STILL isn't running right, remove the main jet and clean the little tiny holes in it out. The tube is hollow and it needs to also be clean between the upper AND lower holes (this is where your real problem lies).

Then put the jet back in, adjust it and drive trouble free.

Just in case this doesn't fix the problem then it is sucking air from someplace.

Save yourself time and just do this when the carb is off and apart... No sense in removing it twice. :beatdeadhorse:

will do- thanks again!