Should be a 1993 model.

First thing to do is go over the Miller website www.millerwelds.com and go to the Resources section, click Owner's Manuals and find Bobcat 225G, then enter your serial number and that will bring up the owner's manual with schematics and part number lists. From there you can get the part numbers you need. Then go to www.miller4less.com and look up the part number and that will tell you if the part is available and if so, what the price is. You can order parts directly from Miller4Less on their website. If you don't see it listed there, then call Miller tech support at 1-800-4-A-Miller and ask for the engine drive service dept. The Onan engine parts you may be able to get at a local small engine repair shop that deals with generators.

 

Yep, I had already downloaded the manual, and went front to back a few times, and the Low Oil Pressure switch has no part number associated with it. The Full KVA kit appears to have been discontinued, as the part number returns no results. I think I found the pressure switch part number listed in an Onan Service Manual. Still, availablilty seems spotty. I'm checking a few engine parts sources for stock.

 

I think I found the pressure switch part number listed in an Onan Service Manual. Still, availablilty seems spotty. I'm checking a few engine parts sources for stock.

Check with member onanparts.com (TJ) for any/all your Onan parts. Hard or impossible to find a better deal and his service is second to none.

 

Thanks Duane, I'll do that.
Had the machine apart over the weekend, and found that the Low OIl Pressure switch was actually fine. The problem was a broken Molex connector in the wire harness.
I noticed that the rotary Power Range and AC/DC selector blade contacts were very grimy. I cleaned them up and lubed them with DeOxit (contact lube/cleaner).
Is there supposed to be some conductive grease on these blades?
There was a blown fuse in the Exciter circuit. (F2) It was a 10 amp, and should have been a 25 amp. I replaced it and tested the welder at various heat settings and it seems to be holding. I checked the bridge rectifier that it's connected to and it also looks OK.
What (exactly) is the Exciter circuit's function? Some type of regulation?
Sorry about all the questions, and thanks to all in advance!
-andy-

 

I completely restored a 225G recently myself. You are going to find that the parts are getting harder to find. Most engine parts are still available...much more than the Miller parts sadly. I would say that Miller is at 50-60% availability. Onan is maybe 90%? For most engine parts, you local Onan dealer is the only one that will have them. Any special Miller parts will have a Miller listing....the rest are Onan.

As for paint, yes, Miller does sell it and it isn't anywhere close to cheap. 25-35 bucks a quart...or more in some cases. I repainted mine with Rustoleum Safety Blue and it was an acceptably close match. You could always go to an automotive paint store with a panel and have them match it. The inside of the panel, once cleaned, should give a good enough color for them to work with. You would get good quality paint much cheaper that way. After paint, Miller still has some of the decal kit around. The large Bobcat decals on the sides are no longer available. I cleaned mine and masked them off. Worked great and kept the original look. BTW, the color you want is Miller's New Blue. I don't have the number in front of me at the moment. Do a search here for Miller blue paint and you should find several threads on it. I have posted the numbers many times. No idea why I can't find them now.:dizzy:

Kits were discontinued a long time ago. Now and again, you can find the full KVA kit on Ebay, but patience is a must as they are few and far between. If I had kept mine, I planned on simply building my own full KVA kit.It wouldn't look as nice, but functionality would be there which is all I wanted anyway.

 

Yum! Nice restoration!!
I found all the parts I was looking for, except the KVA Kit, but I ordered the parts to do it piecemeal.
Too damn cold up here to paint though, it'll have to wait till April or May.
I can take my time with the mechanical needs.
-andy-

 

Thanks. I put a lot of work into it. New Paint, new motor, several dozen generator parts, new faceplate, etc. Hated to sell it a few months ago, but once I got my TB, it just sat around for three years. The full KVA kit was next on my list...then came the TB...so I never got around to it.

 

I have my 225g repainted, and tuned up, running fine.
I have the Super S-32p Wire Feeder cleaned up and also working as it should. Ran a few test beads tonight, and all seems to be working as it should. One Question:
The S-32P has a CC/CV switch, and the Bobcat has CV/CC terminals.
I tried it both ways, and both seem to work.
Is CV preferred over CC? Or vice versa??
The manual doesn't specify one over the other, but there's a little MIG gun icon next the the CV terminal, and I'm thinking that it's preferred.
Thanks,
-andy-

 

CC is for stick and TIG. CV is for MIG and flux core.

 

You will find that the CV range on the 225G is limited. You can run heavy wires easily, but smaller stuff and down low is next to impossible. I ran mine with .035 and .045 flux core in CC most of the time. It gave me a little bit more range than the CV side. Same with .035 hard wire and C-25. Mine would not run short circuit at all, but it was a spray arcin beast with C-10.:drinkup: What you will have to do is play with the parameters to see what your machine will let you do....and won't do no matter how loud you yell at it.

 

Thanks DDA, that's the info I was looking for. After a few days of practice, and trying C10 versus Co2, I found some sweet spots with wire speed and current/voltage that allowed me to make some acceptable welds. Another day of practice with 1/8 inch steel tube scraps, and I'll start on the cart for the beast. Got some very nice beads with C10. (got a few not so nice as well. Finding those sweet spots takes a bit of time.)
The C02 was OK with the old lightweight MIG, but the Bobcat's got some gonads. The spatter and arc instability with straight C02 is much more pronounced with the additional power. The C10 looks like the way to go.
Thanks again,
-andy-

 

Wow! I totally missed the part about the S-32P (CC/CV selectable). Must have been the late hour and nothing to do with commenting on something one has no personal experience with. Sorry Andy for an 'absolutely no help at all' post.

 

Hey, no problem Duane. I'm so green that I should be expected to know only two things:
1) Very little.
2) Next to nothing.
Hammering the basics into my skull is the only way I'll ever learn. I think that I'm beating #1 above, and just now starting to address #2. (heh..)
Many thanks for any and ALL help!!!

 

One thing I noticed that I will need to address in the future, maybe this spring:
One of the slip rings has a very pronounced wear valley on only one side. It needs to be turned and polished, and the local shop needs the rotor removed to accomplish the work. Can the engine/rotor assembly be removed from the stator, and then just separate the engine from the rotor for service?
The reason I aks is that the Service manual I have shows that disassembly requires disconnecting all stator leads, and removing the whole works (stator,rotor,eigine) before separating the rotor and engine from the stator, and THEN rotor from the engine. I would REALLY like to NOT have to disconnect all the stator leads.
Thanks again, and good job on the Bobcat restore in progress Duane!
(If Judy's Chili is as good as my Barb's, I understand the need to relax after consuming)
-andy-

 

Unfortunately, as with my 'donor' unit, yours has to be pulled as a unit in order to split it for rotor removal. At least that 's the easiest way. It's the end cooling fan that throws the monkey wrench in the gears and is why it's easier to pull the whole unit in the long run. The good news is the stator wires have 'latch hook' connectors and only three have to be unbolted from a component to remove the unit. All leads are marked so reassembly identification isn't a problem.

However, as the slip rings are relatively easy to access, I would get a commutator stone (if you don't have one already), remove the brush holder and clean up of the slip rings with the unit still assembled. Obviously you'd have to have the engine running to spin the rotor so extreme caution would have to be observed in the process.

 

WOW! Thanks for the advice Duane, I found a website that sells a kit for resurfacing and polishing the slip rings while in the machine. Saving me lots of time and money!
http://www.martindaleco.com/pdfs/Abrasives/Diamond_D_Commstones.pdf
And I'll pay special attention to the 'extreme caution' advice.
This truly is a great place.
-andy-

 

Duane, maybe I misunderstood your post, but I can tell you that you can definitely separate the engine from the generator section without removing the whole assembly. A couple of years ago I purchased a 225g (mine is a '96 model Onan I believe) that had been left in the weather with no sparkplugs in the heads. Needless to say, the engine needed rebuilding. I was able to slip a wrench through the vent holes and unbolt the engine from the generator shaft and pulled the engine while leaving the entire generator section still mounted in the unit. After rebuilding the engine with parts supplied reasonably by Onanparts, I then re-attached the engine back to the generator doing the reverse procedure using the wrench through the vent holes and never had to detach any of the wires on the generator. I also polished the slip rings with the unit with 1000 grit sandpaper with it all still assembled. Of course, my slip rings were only dirty, not grooved. If I misunderstood the process you suggested, I apologize, but it is definitely do-able the way I did it. By the way, after I had the unit up and running, I took it to my LWS and they put a load tester on it and ran the whole gamut of tests and it came out just fine, and there was NO CHARGE for the LWS doing the test. I was happy!
Doug

 

Doug,
I don't think it was a misunderstanding per se but we were discussing the requirements for pulling the rotor if that were necessary to clean up the slip rings. The earlier units have a second cooling fan driven off the end of the rotor shaft that could be a real pain to pull off with the rotor and stator housing still in the unit. Can it be done? I'm sure it can but to me it would be easier - and less likely to to damage anything - if the whole unit were pulled and then split.

Keep in mind I was talking about pulling the rotor out not just splitting the engine from the alternator unit. I actually split my donor motor the same exact way you described except I slid the stator wrapper back to fully expose the 4 rotor flange bolts for removal and Andy was looking to clean the slip rings with the unit still assembled same as you but with a commutator stone to get the grooves out.

:drinkup:

 

My 225G was an absolute #$*%$ to split. It didn't happen without removing the whole generator. Glad I did that too.....turned out the lower stator mount was cracked and almost to a failure point. Miller told me that was an extremely common problem. It would have destroyed the unit had it failed.

Doug, you may want to look at your if you haven't already.

 

Thanks guys! Great info.
DDA52, can you describe the location of the "common" stator mount crack?
I'd like to take a closer look at mine as well, thanks for the heads up!
-andy-

 

Its easy to find. The stator is held by one bolt on the bottom towards the front of the machine. The mount is a piece of sheet metal channel that is welded to the stator and bolts to the lower bulkhead in the frame. Where it cracks is near or at the edge of the last weld on the stator. I welded mine up and fish plated it on both sides with some 1/8x1/2 strip. It was a bear to weld with all the magnetic stuff going on in there.:dizzy: It was ugly, but it got done. You have to be super careful welding there. If you burn any wores on the windings, you are toast. I wrapped the thing with heavy industrial foil and used several layers..plus a fire blanket. It was ugly, but it worked...no burns or breaks. TIG might have been a better choice since there is no slag, but I wasn't rigged up for TIG at the time.

 

I'll take a look this weekend, thanks again for the warning.
That 225g with the SP32p Wire feeder is a very nifty rig.
I can no longer blame my equipment for dog crap looking welds.
Well, I could, but everyone would know that I'm full of BS.

-andy-