317 engine

317140 · Nov 11, 2011

I just installed a rebuilt p218 Onan engine in my 317. It has an odd problem. As you advance the throttle from idling to speed up the engine it tries to over accelerate badly. I am afraid to run it much as it is a brand new, very expensive rebuild. The odd thing about it is that it doesn't do it every time you try to accelerate. I am trying to find out what to start looking for that could be causing the problem. The engine never had this problem before the rebuild so I am somewhat at a loss.

tomd999 · Nov 11, 2011

Hiya,

Sounds like your govenor linkage isn't correct or it's missing a spring or 2. Look in the service manual and make sure you have it correct.

Tom

hawkeye08 · Nov 11, 2011

x2 on the governor linkage. perhaps a spring missing or in wrong hole? If you did the work yourself, refer to the pictures you took before and as you were taking it apart...

Fixemall · Nov 11, 2011

X3 on the governor spring, it is probably catching on the actuator, turn it over and see what happens. With the engine off run the throttle from stop to full and observe the linkage rod to check for binding, the rod could be backwards or as others have pointed out, in the wrong hole. Don't feel bad if you have it in the wrong position, I have rebuilt hundreds of small engines and I either make a note of position or take a picture on the complicated ones.

317140 · Nov 13, 2011

I have checked and double checked the governor. I had the holes marked with different color ty-raps to aid in reassembly. I have added an additional spring, so stiff that I can barely get the throttle to advance. Nothing I have done has made any difference. I am beginning to think I may have a carbeurator problem. I am thinking that the float may be sticking open and allowing too much fuel to enter. It seems that this might explain my symptoms. Tomorrow I will remove the carb and check it out. If anyone has had a similar problem I would like to hear from you. It seems I can't have a simple problem, it has to be something that drives me nuts trying to figure it out.

Fixemall · Nov 13, 2011

A sticky float will just choke off the engine, produce black smoke and lower rpm. You may have an internal issue where the governor rides the cam gear.

glc24 · Nov 13, 2011

Is it possible that if the governor shaft yoke was disassembled,it may be installed backwards.
I did that boo boo on mine,and that is how it acted.

Greg

317140 · Nov 15, 2011

I took the mower back to the guy who did the rebuild for me. After looking at it and at another 18hp Onan he had in his shop he decided it definitely was a governor issue. So I took the engine back out and we disassembled it. Looking at the shop manual we saw that there was a small roller ball under the governor shaft that was missing. The book showed the procedure for checking to see if the ball was in place. Evidently this had happened before. We replaced the ball and got the engine reassembled. It got too late on me last night to reinstall it in the tractor but I will get to it today. I feel confident we solved the problem with a 10cent roller ball. He was very apologetic for the error and did not charge me for the time it took to repair it. Since he has done a lot of work for me over the years an I have never had a problem, I told him not to worry about it. If you work on equipment all the time these things will happen occasionally.