Explain this Tilliotson HS govenor to me

[Modifiedmark]

Can someone explain why and how this govenor works on a HS carb?

For example when I rebuilt my Dayton/Poulan 245 I put a kit in the carb. Saw started right up and ran fine untill I tried to set the H screw on it. The saw was very rich but I could not get it to clear out and rev up till the H screw was turned almost all the way in on it.

I put the kit in another carb I had and all was fine. I had had he same problem with another HS on a 306A.

Now today after kitting the HS on this Wright blade saw, this carb is doing the same thing! Thing is very rich and wont clean out till the H screw is turn into about 1/4 turn out then it dies. With the screw 1 turn out it just wont hit max rpm and just kinda surges and smokes.

This governor is the brass valve screwed in the side of the carb right? How does it work? Can I replace it or bypass it or what.

I'm all ears boys and girls.

 

[HimWill]

Is that valve the one with a ball bearing inside?Can it be dis-assembled and cleaned?

 

[MS460WOODCHUCK]

Can someone explain why and how this govenor works on a HS carb?

For example when I rebuilt my Dayton/Poulan 245 I put a kit in the carb. Saw started right up and ran fine untill I tried to set the H screw on it. The saw was very rich but I could not get it to clear out and rev up till the H screw was turned almost all the way in on it.

I put the kit in another carb I had and all was fine. I had had he same problem with another HS on a 306A.

Now today after kitting the HS on this Wright blade saw, this carb is doing the same thing! Thing is very rich and wont clean out till the H screw is turn into about 1/4 turn out then it dies. With the screw 1 turn out it just wont hit max rpm and just kinda surges and smokes.

This governor is the brass valve screwed in the side of the carb right? How does it work? Can I replace it or bypass it or what.

I'm all ears boys and girls.

Mark, I think that you just answered my problem! I just rebuilt the carb on a 245A that I just got and it is acting just like you described. I can't get it to adjust to my opinion of how it should run. So how can you tell the difference in the carbs that have the governer and the ones that don't? I have about 10-12 of these carbs and don't want to waste my time on another carb with a governer.

 

[HimWill]

The Dolmar 133 uses an HS carb with the "governor check valve".It shows a gasket underneath and has a footnote to secure the valve with "glue".It does not specify what the "glue" should be.
Maybe nail polish would seal it in place.

 

[Urbicide]

Mark, I sent you a copy of the Husky 2100 manual to your e mail. There is some info about the govenor in there.

Vince

 

[Modifiedmark]

Is that valve the one with a ball bearing inside?Can it be dis-assembled and cleaned?

I don't see how it can be taken apart, and it seems very clean. You can push on the ball inside and it moves very easy. Almost too easy it seems. Passage in the carb is clean also.

 

[Urbicide]

From the 2100 workshop manual.

"Speed governor

The purpose of the governor is to limit the engine
speed in order to protect vital parts like the crankshaft
and ignition system from excessive stresses.
We therefore advise most strongly against any interference
designed to render it inoperative. When the
saw IS run under no-load conditions, the engine
speed IS limited to 10,500 r/min as the governor
comes into operation.

The steel ball and spring in the governor are so devised
that vibrations in the carburettor at a certain
engine speed cause the steel ball to open the fuel
outlet. An excessively rich mixture IS then obtained
and the engine begins to four-stroke, the speed
drops and the vibrations decrease. The steel ball
then closes the outlet, the engine speed increase
and the process IS repeated.

Removal of speed governor

Remove the screw for the choke flap. Pull out the
flap approx. 7 mm and push out the choke shaft
approx 5 mm. Remove the speed governor with a
suitable screw driver."

 

[Saw Dr.]

From the 2100 workshop manual.

"Speed governor

The purpose of the governor is to limit the engine
speed in order to protect vital parts like the crankshaft
and ignition system from excessive stresses.
We therefore advise most strongly against any interference
designed to render it inoperative. When the
saw IS run under no-load conditions, the engine
speed IS limited to 10,500 r/min as the governor
comes into operation.

The steel ball and spring in the governor are so devised
that vibrations in the carburettor at a certain
engine speed cause the steel ball to open the fuel
outlet. An excessively rich mixture IS then obtained
and the engine begins to four-stroke, the speed
drops and the vibrations decrease. The steel ball
then closes the outlet, the engine speed increase
and the process IS repeated.

Removal of speed governor

Remove the screw for the choke flap. Pull out the
flap approx. 7 mm and push out the choke shaft
approx 5 mm. Remove the speed governor with a
suitable screw driver."

Does yours have a spring in it, Mark?

 

[Modifiedmark]

Thanks Vince, that makes sense now that it is explained. It also makes what I was thinking seem right, that it is rich becase that valve must be malfuntioning.

I was over at the Tillitson site and downloaded the parts manual for that HS carb, and it shows a part # for that replacment govenor. Now where to get one?

I wonder if it could be plugged off to try it out that way?

 

[Modifiedmark]

Does yours have a spring in it, Mark?

Yes it does, but like I said it takes almost no pressure to push it in.

 

[Saw Dr.]

Thanks Vince, that makes sense now that it is explained. It also makes what I was thinking seem right, that it is rich becase that valve must be malfuntioning.

I was over at the Tillitson site and downloaded the parts manual for that HS carb, and it shows a part # for that replacment govenor. Now where to get one?

I wonder if it could be plugged off to try it out that way?

I'd flow a little brass in the end of the governor, and wind it in there. You're not going to run that thing enough to blow it up anyway.

 

[HimWill]

I can give you the part numbers for the HS Dolmar uses.What carb number is it anyway?

 

[Modifiedmark]

It's for a 59A and the 58B. I think I found the part #'s for it from the Tilliotson parts list for the HS

How about just putting a flat piece of gasket under it to try it?

 

[albert]

Did you try to tune it in a cut. They can be tricky no load

 

[Saw Dr.]

It's for a 59A and the 58B. I think I found the part #'s for it from the Tilliotson parts list for the HS

How about just putting a flat piece of gasket under it to try it?

Probably less drastic than my idea. You'll never know if you don't give it a try. How come there is always someone trying to keep us from getting ALL the power out of our saws. I didn't realize much of this went on before the EPA, but I guess it was a reliability issue then.

 

[albert]

I think I read in a partner manual turn H in untill it won,t rev then richen 1/4 turn. Unless the saw is ported alot leaving the gov won't matter much in the cut.

 

[Modifiedmark]

Did you try to tune it in a cut. They can be tricky no load

Yes I did on the 306 quite awhile ago. Wouldnt tune then either, too rich and surging.

Like I said, when it happend again on the Dayton I knew it right away and when I changed the carb out, you could tell right away that it was fixed.

 

[Modifiedmark]

Mark, I think that you just answered my problem! I just rebuilt the carb on a 245A that I just got and it is acting just like you described. I can't get it to adjust to my opinion of how it should run. So how can you tell the difference in the carbs that have the governer and the ones that don't? I have about 10-12 of these carbs and don't want to waste my time on another carb with a governer.

I think all of the Poulan HS carbs had them, but I can't be certain.

 

[MS460WOODCHUCK]

I think all of the Poulan HS carbs had them, but I can't be certain.

If thats the case then I will be putting the kit in another one and taking a chance on the gov being good on the next one.

 

[TRI955]

Mark,

Ask and you shall receive!!!! I think you found your answer.


Mike