8n throttle

new to posting but long time reader of posts. normally i'm able to search around and find what i'm looking for but not this time.I have a late 8n with a zenith carb,when moving the throttle lever,the engine rpm's would not start to increase until appox 1/2 way to max travel and under load there was no rpm increase. At some point in it's history this tractor had hit something hard enough to bend the sheet metal,push the radiator into the fan,even bent the hood where it screws to the instrument panel. some of the radiator tubes had been soldered closed,yes it ran hot even to the point of the gas in the tank boiling,the gas cap had been vented and the hole in top of tank was open.I added a temp gauge,new radiator,water pump,6 blade fan(from a bent 4 blade)and shroud so got a governor too. It now stays around 180* BUT, with the throttle lever and engine at idle, moving the lever appox 1" takes the engine to full speed,also the governor does not increase rpm's. I recently inherited this and trying to get in working condition. Looked at another 8n's throttle linkage/movement and it appears the same as mine. Sorry for the rambling, just trying to provide any info as it wandered into my mind. Any thoughts would be appreciated. Thanks Steve

sak5822,Check the spring on the governor,it should have no slop,lust snug at idle position,If sloppy bend the hooks closer together with a large pair of channel lock pliers till you have no slop.

Thanks for the reply, spring is possibly snug if anything. appox 1" to 1 1/2" of throttle lever/handle movement(at instrument panel) moves the throttle shaft on the carburetor to full position.

Thanks for the reply, spring is possibly snug if anything.

Click to expand...

The governor does not come into play until the spring is stretched. The engine speeds up the fly weight in the governor to counteract that lengthening of the spring to hold the speed steady. The lever position is irrelevant. If you want it to start moving the spring earlier just shorten the rod to the governor.



[b:7c770232f2]Op test:[/b:7c770232f2] With engine off, disconnect throttle rod from throttle arm of governor. With hand on governor throttle arm, you should see the carb arm track with throttle arm movement as you pull governor throttle arm rearward. The heavy spring (arrow) connects the two arms and with engine off (fly weights inside governor are now doing nothing), one should follow the other. The spring (arrow) pulls the carb arm (short one) along with movement of throttle (long one) arm. If this does not happen, the spring is too loose or there's a problem with the governor.

Thanks for the reply, spring is possibly snug if anything.

Click to expand...

The governor does not come into play until the spring is stretched. The engine speeds up the fly weight in the governor to counteract that lengthening of the spring (arrow) to hold the speed steady. The lever position is irrelevant. If you want it to start moving the spring earlier just shorten the rod to the governor.



[b:63198f919f]Op test:[/b:63198f919f] With engine off, disconnect throttle rod from throttle arm of governor. With hand on governor throttle arm, you should see the carb arm track with throttle arm movement as you pull governor throttle arm rearward. The heavy spring (arrow) connects the two arms and with engine off (fly weights inside governor are now doing nothing), one should follow the other. The spring (arrow) pulls the carb arm (short one) along with movement of throttle (long one) arm. If this does not happen, the spring is too loose or there's a problem with the governor.