B gov surge

ANyone know how to make a B idle smooth? I rebuilt the motor and it runs good, but the gov wont quit hunting. Anti surge spring is installed, gov adjusted for preload per I&T service manual, new condenser, coil in mag, points filed and set to proper gab. carb cleaned out with fresh gas. I need to check the gas cap vent but after that I am stuck. I am going to try to post a vid in the next couple of days.

Yup, thats the surge spring, its on there.

Seems like this was a topic this winter.How much slop in joints? Wasn't the cure throttle shaft seal?Have seen those seals pinch shaft under vacuum with lip out(like its supposed to be) and for linkage adj can't remember exactly how that was but I know you have more faith in I&T than me.

Could be there is a blockage in the idle circuit of the carburetor.

Don, my B does EXACTLY the same thing and I haven't been able to solve either-so interested to find out what fixs yours.  I have the gov spring too, it helped, but did not fix.

You may want to search some posts by Dick L, I believe he has touched on this issue in the past. 

Several stated things can cause a surge however the most common is that the governor cross over arm is out of adjustment. The adjustment is made by bending the cross over arm to where the linkage connection up by the radiator is out of alignment by about 1/16". Most will say to do it with a wide open throttle.  That works just as well as the way I tell people to make the adjustment with the throttle closed. I only say throttle closed to help the person doing the adjustment to understand the reason for the 1/16" offset in the connection.

  you dont have right surg spring plus its not hooked up right . the spring you  have looks to heavy its fighting the govener try taking it off and see how it runs the govener should stop hunting.

I will do some more testing tonight, thanks for all of the help. Broke a tooth so I have to stop by the dentist first

There's one fundamental cause of and engine surging not yet been mentioned. That's a mistuned carburetor. The book settings on a vintage carburetor aren't set in blood, they are only close enough to get the engine to run so it can be adjusted and having cleaned and rebuilt the carburetor what was right isn't now.

When the idle circuit is too far from the right mixture and the throttle gets closed by the governor, the engine practically dies so the governor opens the throttle and the main jet feeds fuel so the engine picks up speed getting up to the speed set by the governor and spring so the governor closes the throttle. The fix can be as simple as proper adjustment of the idle circuit. Often that is an air adjustment.

The governor works hard at hiding the effects of carburetor adjustments. It works best to override the governor and to hold the throttle closed against the idle speed stop screw. Then adjust the idle mix for the fastest engine speed. Then manually open the throttle at the carburetor and at some large opening set the main jet if adjustable. Alternatively if it wasn't surging you could watch the throttle position and adjust the idle mix with the speed set slow and adjust the idle mix for minimum throttle opening then go to high speed and again adjust for minimum throttle opening as the governor does its work. The adjustments interact so you have to go back and forth a few times.

One more check is to open the throttle rapidly and see if the engine speeds up without stumbling. If it doesn't, you need to run the main mix richer, or adjust the float to have more fuel in the float bowl, then do the mix adjustments all over. I have found that when plowing I get more power with the main (or power) jet running rich.

Surging can come from any of the exotics already posted, or simply a need for proper carburetor tuning.

Gerald J.

It is the wrong spring, its actually a D14 spring I had around the shop, I put that on there for a test...didnt make a difference. I am going to put the B one back on. I going to try some of your guy's suggestions and see if any pan out

boilerrepairman--

Dick,

Loosen the setscrew up by your hand throttle at the steering wheel and pull the rod up until the spring is tight but not to where it changes the idle. You can work it back and forth to get it right. Might have shoulda maybe said push until you have the spring tight. Sittin ana thinkin seems not ta be my best thing ta do but after posting to pull my thinker started to see the bow in the rod when I reach for the high dollar RPM's.

Edited by Dick L - 01 Jun 2011 at 2:49pm

Dean (West MI) wrote: DonDittmar wrote: ANyone know how to make a B idle smooth? I rebuilt the motor and it runs good, but the gov wont quit hunting. Anti surge spring is installed, gov adjusted for preload per I&T service manual, new condenser, coil in mag, points filed and set to proper gab. carb cleaned out with fresh gas. I need to check the gas cap vent but after that I am stuck. I am going to try to post a vid in the next couple of days. Hey Don, did you ever get this issue resolved?  I just rebuilt the carburetor and adjusted the cross shaft arm and now it surges bad.  Just wondering what you may have found out.

Well yes and no. I was rebuilding/painting for a customer and it wasnt my tractor.  I did narrow it to the carb, and no matter what I did I could not make it stop the surging. I had that thing apart 3 times and could make any difference. My customer elected to run it as is so I returned the tractor to him.