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Discussion Starter #1
Good Morning,

I have a 79 JD 400 with the original Kohler K532 engine. Engine was running great and suddenly lost power while mowing and wouldn't restart. I tested and found out there was no spark. I checked the points and found out that the pushrod that activates the points was not moving at all when the motor was cranked over. The points pushrod rides on a cam within the governor. I took the governor apart and found that it was destroyed. After sourcing a rebuilt governor from eBay, I installed it and followed the procedure in the manual for timing the governor gear with the flywheel. I set the points and confirmed that I am now getting spark. Unfortunately the mower will not start and will only pop and backfire when cranked. I also slowly rotated the governor to adjust the timing while cranking the motor over with no luck.

My suspicion is that I may be one tooth off when I timed the governor gear with the flywheel but the marks lined up very well. I'm hoping there is an expert here who may have some insight into the problem

Thanks in advance,

Ethan
 

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I would reach out to Herminator. He knows a lot about 400's.I used to have one but sold it because it started developing issues I didn't want to deal with so can't help you. If that doesn't work then go over to Weekend Freedom Machines.com there are a lot folks there with 400's. You may also want to search Ebay and see if you find the factory service manual, it gives step by step on all repair tasks for the tractor.
 
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I would reach out to Herminator. He knows a lot about 400's.I used to have one but sold it because it started developing issues I didn't want to deal with so can't help you. If that doesn't work then go over to Weekend Freedom Machines.com there are a lot folks there with 400's. You may also want to search Ebay and see if you find the factory service manual, it gives step by step on all repair tasks for the tractor.
Thank you for the advice!
 

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I have done that before. Here are the pages for governor alignment and timing. As the pushrod cam wore the timing got more and more off. I think it would be more and more retarded. If you have not pulled the heads off and cleaned the carbon off them, the piston tops and valves you may want to. The carbon will build up to the point where it will damage the top of the piston and the valve seats. That may be your backfiring issue if the valves are not seating properly.

Grandpa J knows a lot about these and may have other ideas as well.
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Discussion Starter #6
I have the manual for the Kohler K532. Is it possible to be off 180 degrees?
 

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I don’t think so if you can see the DC on the flywheel. I also think both plugs fire every time so it wouldn’t matter.
 

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I have to just be one tooth off. Unfortunately I can’t see the DC Mark because somebody used a paint marker on the flywheel so hopefully they painted on the correct mark.
 

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I have to just be one tooth off. Unfortunately I can’t see the DC Mark because somebody used a paint marker on the flywheel so hopefully they painted on the correct mark.
When I did mine I remember something like instead of it saying DC there was some other mark. I just have it in my head that I needed to pull the plug and make sure it was at top dead center because what I read and what I saw seemed different.
 

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Discussion Starter #11
Thanks for all the help! I will likely tear it all apart again on Friday night or Saturday morning and report back to you all. I really like this mower and want to keep the original Kohler until it forces me to repower.
 

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Just saw this thread.


 

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Discussion Starter #13
Welp I gave it another try tonight using the JD manual but unfortunately I still can’t seem to get the damn thing to run. Beveled gear on governor and timing mark on the flywheel are lined up but still won’t run.
 
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