C-100 onan conversion

[nmassey02 13]

Hey guys I'm new here, but I figured I would share my project I have going on. My neighbor was going to take his old c-100 to the land fill and I asked him about it, he said if I wanted it, it was mine. So I picked up for free! I have a 520-H that I'm pulling the onan off of and using it to power the c-100. My later plans are to put the hydrostatic rear end under the c-100 too. Yes the 520 was in perfect running shape, but I never was fond of that body style, so I'm building one! 

 

Edited May 24, 2015 by nmassey02

[C-101plowerpower 1,605]

I'm liking it

[rmaynard 14,888]

Here is another member's journey down the same road.

http://www.wheelhorseforum.com/topic/14371-going-to-make-a-c-200/?page=1

[Racinbob 10,276]

I never would have thought it would fit with that style of hood but it looks like it grew there. Glad you saved it from the landfill.

[nmassey02 13]

I got it fully mounted, and wired to run. Threw gas to it and it fired right up. The onan on the 520 wasn't charging, but the kohler on the c100 was. So I wired the onan to the kohler voltage regulator and it's charging again! That saves about $60 for an onan voltage regulator. The gas tank seems like it should fit in the factor location but the battery will not. So I have to figure out a spot to mount it, I'm thinking under the rear seat pan. I couldn't drive it around as the drive belt from the c100 wasn't long enough so possibly sometime this week I'll pick a belt to fit it. Also the pto arm wasn't long enough to to reach the onan so I'll have to switch that part over from the 520

[nmassey02 13]

Got a little more work done today, I removed the exhaust so the hood would fit on. The throttle and choke cables from the kohler were long enough but needed to be switch around to have the throttle and choke levers on the right ones. Today I also managed to swap them around so they would be correct. I took a picture of how much room there is between the top of the carb cleaner and the top of the hood. Also I replaced the ammeter with the factory one from the 520, and there was a capped over gauge hole by the shifter on the c-100 so it's going to get the rpm tach from the 520 also. The muffler got the pipes cut off of it as well. Progress is going quite well.

[nmassey02 13]

[Catmanii 36]

Looking well so far, the Onan should make the ole Horse get up and move.

[nmassey02 13]

I was able to get a drive belt today, along with lengthening the onan's exhaust. The hood completely bolted and mounted now. It won't let me upload any more pictures, I can upload anything file over 1.89MB right now for some reason. 

[bmsgaffer 2,043]

Become a supporter (to help offset the costs of the forum) and you will be able to upload lots of big pictures easy!

[bmsgaffer 2,043]

http://www.wheelhorseforum.com/store/
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Well worth it!

[nmassey02 13]

Today I got the pto arm from the 520 put on the c-100 so now the pto can be used. All that's really left is make a battery box to hold the battery, then do a final wiring. The muffler was raised up in the front to allow easy acces to the clip on the pto lever. 

Edited May 29, 2015 by nmassey02

[nmassey02 13]

Looking well so far, the Onan should make the ole Horse get up and move.

No kidding! The onan doesn't bat an eye, it has more than enough power it seems! 

[GT14 243]

Nice swap, amazing what you can fit under the hood.

[nmassey02 13]

Hey guys I know it's been a while since I've updated. Instead of building a new box for the battery, I discovered the battery off my four wheeler would still fit in the factory location. I put it on the mower and it spun the onan right up, so I went out about bought a battery to fit it. Then I wired up the head lights and swapped the back wheels and wheel weights from the 520 onto the c-100. Next I'm going to try and swap the 520 front axle to the c-100. I've been mower the past couple of days with the c-100 and everything seems to be functioning just fine. I've had a few little electrical problems here and there but that's to be expected with this kind of swap on the first go around. 

[bmsgaffer 2,043]

From what I understand, you will need to swap over the bell crank (the thing that lifts the attachments) from the 520 if you do the steering swap as the reduction steering interferes with the standard one.

You may run into an issue with that battery cranking over the onan in the winter, but if you keep the charging system in good shape and dont let it sit too long without charging/running you may be OK.

[Kelsey 54]

Your tractor says " Git out ta way, I got work to do!"

[nmassey02 13]

From what I understand, you will need to swap over the bell crank (the thing that lifts the attachments) from the 520 if you do the steering swap as the reduction steering interferes with the standard one.

You may run into an issue with that battery cranking over the onan in the winter, but if you keep the charging system in good shape and dont let it sit too long without charging/running you may be OK.

 

I'm not really wanting to swap the reduction steering. Just the front axle, so if I ever decide to drop a 60" deck under the mower it will fit. But I've never pulled the front axle on a wheel horse, so I'm not really sure what it consists of to remove one.

[nmassey02 13]

It's been a while again, I've been busy so this has been on the back burner. I was mowing with the c-100 two weeks ago and the motor lost all power. It would barely run without out a load on it. You could tell by the sound it was only hitting on one piston instead of two. I pulled the exhaust off, the intake manifold off, and pulled the covers to see how the valves were set. The intake valve on the front piston was never closing fully. I adjusted it to 0.005, which is about the only thing I could find that said what the intake valves were supposed to be set at. Fired it up and the power was back, the motor runs stronger than it ever has, since I've owned it. The only problem now is that it is extremely hard starting and I cannot figure out why. It was hard starting before I adjusted the valves too. Once the motor starts though it will fire right up again, and like I said it has all the power it needs. Any ideas anyone? 

Edited July 13, 2015 by nmassey02

[Theroundhousernr 589]

It's been a while again, I've been busy so this has been on the back burner. I was mowing with the c-100 two weeks ago and the motor lost all power. It would barely run without out a load on it. You could tell by the sound it was only hitting on one piston instead of two. I pulled the exhaust off, the intake manifold off, and pulled the covers to see how the valves were set. The intake valve on the front piston was never closing fully. I adjusted it to 0.005, which is about the only thing I could find that said what the intake valves were supposed to be set at. Fired it up and the power was back, the motor runs stronger than it ever has, since I've owned it. The only problem now is that it is extremely hard starting and I cannot figure out why. It was hard starting before I adjusted the valves too. Once the motor starts though it will fire right up again, and like I said it has all the power it needs. Any ideas anyone? 

Take the top of the carb off the bowl and blow out all passages in the carb. Take your time and do it right. If this does not solve things, I would do a compression test on the motor. In fact , do a compression test first. I hope its not the case but it sounds like your onan is coughing up a valve seat..... Would be a shame with all the work you have been doing. Most of the time , hard starts on a onan but then will run with power is poor compression due to valve seat.

[nmassey02 13]

I will look into it, how do you go about fixing the valve seat? Pull the heads, and resurface where the valves seal off in the block? Also do you happen to know what normal compression should be on the onan? Thanks for all your help, I've only messed with single cylinder kohlers before this. 

Edited July 13, 2015 by nmassey02

[Theroundhousernr 589]

Minimum compression is 75 psi with a maximum of 10 psi difference between both cylinders. Most of mine come in around 100 psi. Around 75 psi would indicate serious wear. Valve seat repair should be done by a reputable machine shop. What happens is the valve seat works loose due to excessive heat. The excessive heat can stem from all sorts of issues debated here on the forum but valves out of clearance and grime on the cooling fins is a big one!  Once the valve seat has came loose in the aluminum bore. The valve hammers the crap out of it driving it down further and if left to long will destroy the bore also. 

 The shade tree mechanic fix would be to peen around the seat to smash the aluminum into holding it down for a little while longer. A good machine shop will open the bore to accept an over sized valve seat and install accordingly.

So I would check compression first because its easy to do. If everything checks out , then I would tear into the fuel system and check spark for the hell of it. You would not believe how well a sick onan will run and fool even the better mechanics.