Welcome to the DoItYourself Forums!

To post questions, help other DIYers and reduce advertising (like the one on your left), join our DIY community. It's free!

small block problems.


FazTaz's Avatar
Visiting Guest

Posts: n/a

01-27-04, 08:09 PM   #1  
FazTaz
Replaced my small block, but still having problems. Don't wanna blow the new motor!

Hey all I just finished replacing the small block on my Craftsman 7HP Tecumseh motor snowblower. Everything went without a hitch, just a couple of problems. The throttle linkage (aperture that controls the throttle), doesn’t seam to be working properly. The unit is either on or off? Does anyone have a diagram as to how the wire that holds the three pieces of the throttle linkage is attached the various pieces? I think it may be wrong? Also the unit seams to be running excessively fast. Its not misfiring, but it sounds like its running much faster than before. Im not sure if this is due to the bad attachment of the Throttle Link to the carb and governor, or is this fine because I have a new block (with clean valves, the old ones were dirty as hell)? Also what exactly does the governor do and how does it work? All I know it that its attached to a small gear in-between the crank and cam shafts).

The snowblower is also having problems moving. I think this may be due to the fact that I let a little cousin of mine help (after whining for 20 minutes), and he may have sprayed some WD40 on the disc and friction wheel when the unit was tipped over. Aside from whipping it down anything else I can do?

AS usual any help would be greatly appreciated.

If anyone can help me with how to properly install the throttle linkage I would be most greatlyful!

 
Sponsored Links
jughead's Avatar
Member

Join Date: Oct 2003
Posts: 597

01-27-04, 08:29 PM   #2  
The governor stands between the throttle cable and the throttle plate in the carb. When you adjust the throttle cable all you should be doing is changing the tension on a spring. The lever that is connected to the governor shaft should be adjusted so that when the throttle cable is in the start/idle position the throttle plate in the carb is just open with only a little tension on the spring. The thottle plate inside the carb should be at a full open position when you start and the governor will retard the throttle automatically when the engine speed picks up. When you advance the lever hooked to the throttle cable you increase the tension on the spring. The engine will speed up and the governor flyweights will produce more force to balance the increased tension. If you didn't have a governor on the engine the speed would vary greatly with load. The engine would overspeed if you went from a heavy load to no load suddenly.

 
Terminator20's Avatar
Member

Join Date: Aug 2003
Posts: 865

01-28-04, 08:06 PM   #3  
How Governor Works

How Governor Works = When you put the engine under load the governor should advance the throttle perhaps to full depending upon the extent of the load. The governor is two flyweights that move out due to centrifugal force and pushes against a spring that is connected to the throttle linkage. You should ,for sure, see the throttle linkage move by the governor when going between no load and full load. That might be hard to see directly on some engines. If there is no movement it could be that the flyweights are stuck or the little thimble is frozen on the shaft it rides on. Before you start the engine the throttle linkage should be holding the CARB at full throttle and when the engine starts the governor will close off most of that throttle to run the engine at a reasonable no load speed by the centrifugal force acting against a spring on the throttle linkage. When you advance the throttle manually you are only changing the tension of that spring which the governor pushes against. If the governor ISN'T working for some reason you could expect a radical change in speed between no load and full load. If the engine is running at a reasonable speed at no load and the governor is stuck you could expect the engine to bog down and almost quit when a load is applied because the governor can't advance the throttle to maintain constant speed in the face of the increasing load. If you don't have a governor your engine would eventually if not right away tear itself apart!!!

 
Search this Thread