Model R Decompression Adjustment

[fixer2u]

Hey all,

I just rebuilt the pony motor on my model R and also did some work cleaning up under the valve cover and adjusting the valves. Yesterday I got everything back together and all seems to start and run well, but my decompression lever does not seem to be fully engaging. I can feel the valves being engaged a little, but when I pull the lever when the big engine is running, it is not engaged enough to kill the bog engine. Now I did not intentionally make any adjustments to the decompression lever, so what might have happened? By adjusting the valves, (which were a little tight) did I throw off my decompression settings?

Thanks in advance!

Nick

 

[JIM MN]

YES, when you adjust engine valves, then you check the decompression settings..
Valve tappet adjustment must be accurate.. Adjust four-valves on a warm engine to .020 ..
Use a dial indicator if tappets are worn.. Adjust no-1 cylinder; turn 180 degrees; adj.
no-2 cylinder.. Valves adjusted--do check the decompression lever setting...

 

[fixer2u]

Ok I see. Yeah I was just following along with the operators manual maintenance recommendations. It talks about adjusting the valves, but mentions nothing about the decompression lever. ut I will go back and redo the procedure. Thanks for the info! Also the manual says to make all tappet adjustments with the engine cold not warm.

 

[toddduff]

What's the valve recession specs for a John Deere R?