Does anyone know where I can get a small governor return spring for my S8D engine? I'm wondering if part of my problem is that the tiny little spring I have on there now isn't strong enough to operate the throttle plate properly. I don't think that is the problem. (more info below) It seems like the engine wants to race off sometimes and like the governor isn't holding it back properly. Of course, if the governor spring is too strong, it might not be able to give it more throttle when the engine is under load. No. ....The governor spring causes the throttle to open more, not close. All the governor controlled Wisconsin engines had a return spring, right? No. It's not like someone added one to mine and it was never designed to have a spring? Some Wisconsins had them, some did not.
I watched your video again. ....Sadly, it takes forever to download with my DSL connection. ....I think you may be confused on just how the governor is supposed to work. ....See my explanation under #7 below.
(1) What is the Spec
number of your S8D Wisconsin?
(2) The high-speed mixture adjustment (with the "T" handle) is at the lower left side of the carb.
(3) The idle mixture
screw is on the upper left side of the carb.
(4) The idle speed
screw (aka throttle-stop screw) is located on the engine side of the carb. ....This sets the minimum
speed at idle.
(5) What weight oil are you using in the engine? ....If the oil is too "light" it will smoke. .....SAE 30 is good for these engines. ....5W-20 or 10W-30 will tend to smoke if the rings or valve guides are worn.
(6) You appear to be missing at least one of the sheetmetal covers which directs cooling air from the flywheel over the cylinder head. (Wsiconsin part # SE-297). ....This can cause the engine to run hotter than normal.
(7) Where is the light spring, which you are questioning, attached? ....I see one end is attached to the governor arm, but where is the other end attached?
The large governor spring (except in the idle position) pulls on the lower part of the governor arm, which in turn, moves the upper end of the governor arm (counter-clockwise) away from the carb. ....The solid link connected to the upper part of the governor arm causes the throttle butterfly to open.
The governor mechanism inside the crankcase causes the governor shaft to rotate clockwise. ....The governor arm clamped to the governor shaft also moves clockwise, opposing the force of the governor spring. ....The link connected to the top of the governor arm closes the throttle butterfly slightly to decrease engine speed.
When the engine speed decreases to the point where the governor spring tension exceeds the force of the internal governor, the throttle butterfly will open, increasing the engine speed to the point where the governor force will overcome the tension of the governor spring again.
This cycle keeps repeating. ....However, if all adjustments are correct, and everything is functioning as it should, the "cycling" is minimal in its extremes and is barely noticeable. ....The amount of load on the engine, and the mechanical condition of the engine, also affect how finely the governor operates.
I have seen the small, light spring on some engines, but they are not on all Wisconsins. .....They have nothing to do with the function of the governor. ....Some are there to eliminate slack in the linkage, while others are there to close the throttle when there is no tension on the governor spring. ....That is why I asked where the one end is connected.
When the throttle is closed, it rests against the throttle stop screw. ....This is where the idle speed is set. ....If the idle speed is set too low, the engine will stall or run rough. ....If set too high, the idle mixture screw has no effect on the fuel mixture at idle.
As you can see, there are lots of variables which need to be properly evaluated and adjusted.
(8) The governor arm is clamped to the governor shaft. ....It is possible that these two parts have moved from their proper setting.
(9) Is your starter still struggling to crank the engine as it did in the video?
I hope I have not confused you more. ....I will try to help you as much as I can.