JD 445 FD620D Governor Question

[Jim334]

I've been running my JD445 for almost 7 years now with little to no issues, that is until this winter/spring. When snow blowing, noticed a few oil drops on the driveway and assumed it was related to the grease I had used on the drive chain on the blower. In the spring, noticed at WOT there was some smoke coming out of the muffler. Hour meter is around 500 hours or so. Did the research and decided it was time to re-ring. Tore the engine down and found everything in fairly decent shape, within spec, etc. and went ahead with the re-ring. Besides the rings, replaced the plastic oil pump gear with a steel one, replaced water pump, thermostat, and governor all for good measure while I had it open. Cleaned and re-seated the valves, replaced valve guides and springs, and adjusted the rocker arms to spec. Engine already had the steel cam gear. Seems like I got it all back together correctly and it fired right up today. Good news is there is no more smoke!

After some warm-up/break-in time, ran throttle up to WOT. Engine started to choke and surge and I had to pull back throttle to let it catch up. I'm concerned I may have the wrong governor. I took pics during disassembly to have something to fall back on if needed. In the photo of the front cover, you can see the governor has weights on the wings and is brown plastic. Second pic is of the governor itself. When I ordered my replacement parts, was told the part number of governor for the 445 and it's wings are un-weighted as seen in the last picture (stock photo).

I have not yet worked through the governor adjustments although I never removed the governor arm from the case. Could the governor I received be the wrong one for the 445 and be the cause of the surging at WOT?
Just wondering if any others may have seen/had/heard of similar issues. I have thus far been unable to find a governor that looks like the original one I removed. I have no reservations of taking the case cover off and putting the old governor back in, just don't want to run through too many gaskets in the process.

Looking for any suggestions to get my 445 back to a healthy (working) condition.

Thanks in advance!

 

[Richard001]

After some warm-up/break-in time, ran throttle up to WOT. Engine started to choke and surge and I had to pull back throttle to let it catch up. I'm concerned I may have the wrong governor.

The setting of the governor would have nothing to do with the engine getting to much or to little fuel. A miss adjusted governor may allow the engine to run to fast or to slow, but will not affect the fuel to the engine.

Are you positive that you got the cam timing correct ?

Did you do anything with the carb when you were working on the engine ?

Richard

 

[Jim334]

100% on the cam timing. Did nothing to the carb except wipe off excess grime from the outside. I did see other posts hoses having small cracks and not being able to maintain pressure in the line, however this surging was not occurring prior to the re-build. I also did not remove/modify the governor arm or link. Just disconnected the springs when removing the carb and manifold.

 

[Richard001]

Clean the carb.
Make sure that your intake gaskets are in place and the bolts holding them in place are tight.

 

[Jim334]

That's the plan for the weekend. Will report back on progress/status. Thanks

 

[Zebrafive]

Which P/N governor did you buy? JD parts list two P/Ns
AM105569
AM129809

 

[Zebrafive]

Also could be leaking intake/carb gaskets causing it to run lean.

 

[Jim334]

The governor I got was Kawasaki part # 49110-2073. I was asked what tractor the 620d was being used on and was assured this was the correct governor. As mentioned above, the one that came off was dark brown plastic with weights on the inside edges of the fly wings, where as the one provided was white w/o any weights. The governor I have in now looks identical to AM105569, while I believe the one I should have is AM129804. It's difficult to tell since I cannot find a detailed pic of the AM129804 governor anywhere.

I did a full replacement of all gaskets/seals and torqued everything to spec and everything seems tight. I readjusted the governor today and measure all the sensors for resistance per spec and they seem fine. I fired it up and it's working better, revs can go higher than before but it still chokes out at higher RPM (nor sure just how high). I can see the fuel coming in from the injector, and it seems like there is plenty of fuel in the throttle body area. I also see the throttle plate close and re-open when it "surges" and the only connection would be the governor arm.

Is it possible that I'm hitting the high-end and not knowing it? I will check the RPMs tomorrow night to see what I get at low idle and then high end before it surges. I'll also re-check all the torgues now that it's been running a bit. I am contemplating opening her back up and replacing the new governor with a new one, this time the AM129804 and see how that goes. If that doesn't solve the issue, I'll need to take a harder look at the fuel delivery, although it was fine before the rebuild. Would I get any benefit from removing the injector and cleaning or replacing it?

I can provide a video if a more visual showing of the problem might assist. Thanks for any advice/direction you can point me in.

 

[Zebrafive]

I think I would buy the other governor and see how it compares to the one you removed.