No power at all

[FCUBMAN]

From your description of sputtering and spitting, I would say that the governor has nothing to do with the problem. Have you checked your plugs, distributor cap, rotor, and wires? It sounds like it may be an ignition miss or fuel problem. Carefully check the inside of the distributor cap for moisture or carbon tracks, and the points for cleanliness. Check the rotor for dirt, pitting, carbon tracks. Any oil or dirt on the points will reduce the voltage to the plugs. I would suspect the coil, but you have changed that, along with the plugs. How about pulling at least one plug and seeing how it looks. Is it sooty with unburned gas? Wet with oil? Wet with gas? Look for anything that would reduce or short out juice to the plugs.
Just my $.02 worth

[John *.?-!.* cub owner]

Rufus, the adjustment bolt you described is called the surge limiter. It moves a spring such that it stops the governor form allowing the engine rpms to run up and down with out load changes. that should not be causing your problem. You need to look at fule system (carb) , or ignition, including timing.

[Rufus]

Well I rebuilt the carb as it was leaking gas all over the place anyhow and followed the Lurkers carb fixes pretty closely and I found that the mounting flange to the manifold was warped and the two halves of the carb were really distorted so after about 6 hours of fiddling around with the warps and using thread sealant on everthing, I installed it on the tractor which seemed to cure the spitting and spudering at high speed although I didn't drive it anywhere. Now for a new problem, I have almost no control over the speed at the throttle control. What I mean is the motor doesn't run away, it just seems like it's mid throttle, when it's all the way to idle. Before the carb work, I decided to fiddle with the bolt that is on the govenor that is easiest accessable with a lock nut on it. I read somewhere that you should screw in the bolt all the way in and back off a 1/4 turn I think...anyway it didn't seem to hit anything while turning it in, so I removed it to find the bolt is indeed hollow and there is a spring inside the hole that protrudes out. This is what it should "bottom" on I assume. Anyway, I found it odd that the spring was REALLY wedged in there. So much in fact I had to screw the spring out by turning the spring. I guess my question is, should it be able to wedge tight in the hole like that ( I mean if it was used for the spring spacing, I would have thought that the hole would be flat on the bottom instead of tapered from a conventional drill) and what length is acceptable for a proper spring? Mine measures .837 uncompressed.

[Rudi]

Rufus:

Sounds like you could have used the Carb Straightening Jig for this excercise.. but washers, care and a lot of patience will work wonders on these old 3/4 updraft carbs. Now that you have pretty much corrected the fuel problem by following Carl Kurnas's excellent articles on Lurker Carl's Carb Fixes, I would suggest that you read his next offering which is Lurker Carl's Cub Governor Rebuild. This Rebuild presentation was done on my 51 (Jethro's) Governor. It will pretty well explain the whole process which can be used for diagnostics as well.

Use approved IH parts for this.. it is well worth it. The complete rebuild was on the tad expensive side for parts.. but having an IH Tech with almost a 1/2 century worth of experience to the rebuild was worth every penny.

[Rufus]

I went outside and fiddled with the adjustment and still can't get the trottle to respond. It seems like it's at full trottle all the time. Even when moving the throttle control at the seat, the rockshaft doesn't move. Oh even with the throttle shutter at the carb are nearly closed. Is there a way, I might have assembed the carb wrong since at the idle position at the controls the operators position and the butterfly on the carb nearly closed off and I still have more rpms than I am used to or do you think that the PO tweeked something to comensate for the messed up (all bent and warped up) carb?

[Rudi]

Rufus:

K, this is what I would do. It may or may not be the fix, but it is where I would restart. (oh, been there , done that .. forget how many times )

Go to the Blue Ribbon Service Manuals and the GSS-1411 Service Manual for Cubs and Lo-boy Tractors. Go to Section 2 - Fuel.

Go to Page 2-9B. Look at the Carb illustration FESM-3209. Item #22 is the Idle Adjusting Screw. Turn it in all the way, do not over tighten.. just touch the end. Then turn it back out -- 1 to 1-1/2 turns. Then go to the Idle Set Screw (not shown, but spring item #3 is) and back it out a bit.

See if that helps reduce the rpms.

If not then:

1. Look at figure FESM-3621A on Page 2-6. This is the IH 3/4" UpDraft Carb.
2. Check and make sure that the Choke Control Rod is hooked up correctly, so that it moves freely.
3. Check and make sure that the Governor Linkage Rod - also is connected correctly and moves freely.

If I remember correctly, the Governor Linkage Rod is connected so that the connecting llink is in the downward position. If the Governor Linkage Rod does not move freely, then follow the linkage forward to the clevis and the connection to the Governor Rockshaft and Bracket Extension Assembly. (See Section 2-15 figure FESM-3211). Make sure that the Rockshaft moves freely. If not, then lubricate with a good Penetrating Oil.. NOT WD-40... Lubricate all moving parts including the Bumper Spring, the extension bracket right up to where the Speed Change Lever Stop sits in the Governor Housing.

If that still does not help. You will probably need to look at the Governor Rebuild Presentation.

A good tool to have would be a Tachometer -- manual one such as the Stewart Warner 757W

to check the rpms. Use the recommended low idle setting of 475 rpm if you can get it there. This can be found on Page 2-2.

I hope this helps

[Eugene]

Probably not, but something to check. At the carburator. Do you have the choke rod connected to the choke lever on the carburator and the throttle rod connected to the throttle valve lever? You can install the rods in the wrong levers.

Eugene

[Clark Thompson]

I would sudjest doing a compression test. A good engine should have around 120 to 140 lbs of compression. I just rebuilt a cub engine that had very low power. I did a compression check for the sake of doing it. The compression ranged from 75 to 90 lbs. this is too low to produce the power the engine should. I would say any compression less than 110 is too low. One way to tell if the rings are worn is to do a compression test cold. take a reading. then squirt some oil in the cylinder and do test again. If there is a noticeable rise in compression then there is a problem with the rings. if there isnt a noticeable rise then thereis a problem with the valves.

[Patbretagne]

Hi, have I got all the information correct? the engine speed doesn't change, it seems to be revving fairly high and the throttle control from the driver's seat is not altering the engine speed.

You say "the rockshaft doesn't move" is this not the main clue to the problem here, if the rockshaft doesn't move when one moves the throttle there is something stuck. Perhaps, and I only say perhaps, the govenor or part of its linkage is siezed, I have found on Baby that the rockshaft from govenor to the carb was slightly siezed into it's bearing in the top of the govenor housing not giving adequate throttle advancement when the govenor asked for more gas.

I respect clark's idea, but the engine is running, but will not respond to the throttle control, so get that sorted first.

Have you tried working the throttle direct on the carb itself, if you can alter the speed of the engine by altering the position of the throttle AT THE CARB it would lead me to look at the linkage and govenor.

Best wishes, hope you get it sorted
Pat

[Eugene]

The govenor was working - perhaps not 100% properly in Rufus' first post. So, it should be functioning after the carburator installation.

It's either the carburator was assembled incorrectly. Or, the linkage is connected incorrectly at the carburator.

Eugene

[Patbretagne]

Hi Eugene,
I agree, but it is Rufus who says himself a couple of posts ago that, and I quote, :-

"Even when moving the throttle control at the seat, the rockshaft doesn't move."

Difficult to say from a distance though.

Pat

[Eugene]

Pat. Correct, we are at quite a distance from the problem.

My thought is that moving the throttle lever actually only compresses or extends one or two of the springs which provide external control to the govenor.

Again, my thought, something is binding the rockshaft. The only thing that has changed, that we know of, is the carburator rebuild and installation.

If this were my problem, I'd start checking things at the carburator. Checking linkage installation would be first - simple - easy.

What can I say? I'm still in my night clothes. This could be my second mistake of the day. Getting out of bed would be the first.

Eugene