So my Kohler CH18S had a coil problem. One coil tested out bad. So I replaced both coils while I have things apart, ... and now I have a coil grounding issue.
When the kill wire is connect to both coils, the engine will not start.
If I remove both kill wires the engine will start, and will consequently stop when I reconnect the wires.
If I remove one kill wire from either coil, the engine will start and run on one cylinder, until I reconnect the second kill wire and then the engine stops.
If I disconnect the kill wire going to the wire harness, it makes no difference to the above.
It appears that the kill wire connected in series from one coil to the other coil is grounding out from coil to coil.
I have no idea why this might be. Unless I simply got the wrong coils.
So I thought I would ask advice before I go rewiring myself a separate kill switch while I have everything opened up. Or I guess I could fall back to just choking it to turn off. Hmm....
Seeking guidance for tuning a CH18S Kohler Command (1995), as replacement for a 16hp Onan (1990).
This Kohler doesn't have the torque-grunt of this Onan, but it works, and is my available option.
So, how best to tune the Kohler for this application?
1. I believe Onan and Kohler high RPM setting are both 3600?
2. Would it hurt the Kohler to boost that RPM to 3700-3800? Would it really help any?
3. Would it hurt the Hydro Transmission to go over 3600rpm?
4. I guess I could go find a slightly smaller Drive Pulley? And what would then happen to the Trans if I can't get the proper RPMs to the Trans?
Now that I've figured out the mounting arrangements I can always swap in a bigger engine should I stumble upon a better option.
Given the difficulties of getting the Onan rebuilt now-a-days, I'm looking to go for a more modern engine with easier to find parts/service. And I'm not inclined to do an engine rebuild myself.
I'm looking for help in troubleshooting a starting problem with my 520. I used it yesterday to mow my yard for about 1.5 hours and when finished I let it cool down before shutting it off. It sat for about 2 hours and I put fuel in it and drove it on the ramps to clean the deck and after rolling it off the ramps I hit the starter and the engine made a noise and tried starting. I tried several times after that and no pop at all so I did a compression test and the front cylinder was fine and the rear was poor so I immediately thought of the valve seat being loose wedging the valve open. This morning I took the head off and much to my delight I did not see the seat as I thought but the head bolts were not very tight so I understand the poor compression (see pictures). The piston goes back and forth so that seems fine so I'm not sure where to focus my attention next. I am new to the 520 world and I tried searching the forums to find a thread that might walk me through this to no avail. I'm going to hold off putting the head back on just in case someone says to check something else related. This machine is new to me and has been smooth running, no smoke, good power, and always started easily with very little choke so I'm very surprised at this. Any help would be appreciated.
By krohs nest
The trigger is bad. Replacement is costly.
Looking at Brian Miller's replacement kit. Any comments.
By Armin Buehlmann
I read through a few related posts but my symptoms sound different.
Have an '89-'90? Wheelhorse 520-H, model 4120OE01.
When I engage the PTO, the engine stalls. No fault indicators.
However, everything else seems normal:
- all lights work when pressing 'TEST'
- when I engage the PTO without sitting on the seat, the engine also stalls, but the 'SEAT' light comes on. Normal.
- when I try to start the engine with the PTO engaged, it won't start and 'PTO' lights up. Normal.
- after disconnecting the load (2-stage snow blower belt in this case) from the PTO, I get the same problem, engine stalls immediately. PTO pulley turns along fine with the remaining motion.
And I also need to mention: the first time it happened it was intermittent. The tractor and snowblower attachment were used over a month ago, without any problem.This time got above symptom upon startup. I didn't feel like shoveling so after revving the engine for a minute or two and a few 'encouraging' words, it worked. I switched the PTO off and on several times afterwards with no problem (engine warm, obviously). Today, with the engine cold, the problem is back.
I think there's enough reason to rule out the PTO- and seat- switches. But what else should I check?
This is my first time writing in the forum and I hope I've given enough clues without boring you.
Any hints and advice are appreciated.
PS any good tricks to counteract the belt tensioner on the 2-stage snow thrower (model 79361)? It is a bear to connect and disconnect.