Repowering 8199G

[daugen]

my 1986 Gravely is in good shape having been taken down to the frame by yours truly, but I have not touched the
750 original hour engine. It runs, makes decent power, but the dirty exhaust and chronically sticking points
are a pain. Does anyone here have experience with repowering with the 23hp Vanguard? They used to make a Honda repower
but that seems to have disappeared. I intend to keep this tractor forever, so I don't mind investing in it. It's used constantly for
field slope mowing, cart pulling, moving machinery with its ball hitch and blowing snow.
I have an ignition conversion kit I intend to install this winter when I have time, but that's only a patch.
pic of unit with my homemade rear weight box:
TractorData.com Gravely 8199-G tractor photos information
thanks
Drew

[gravelymay]

Hi Drew
The Honda is still a possibility

Honda 690cc GX Series V-Twin OHV Engine — Electric Start, Remote Throttle, Model# GX690RTDW | 601cc - 900cc Honda Horizontal Engines| Northern Tool + Equipment

Briggs are harder to seal off but will work

Call me If I can help 423 716 4611

Bruce g

[RichardTX]

I have done a few engine changes but I took the easy way out. I bought Onan 24 hp P224 engines and bolted it on. In essence I turned a 18G into a 24G and a 8129 into a 8249. Since Gravely already made tractors with Onan engines, sourcing an adapter plate was just a matter of patience and persistence.

I have paid anywhere from $300 - $700 for a good P224. Onan adapter plates have cost me anywhere from $15 to $45.

The second most expensive item when putting an engine on is the exhaust system. I think I spent about $175 for my exhaust systems including chrome muffler clamps. I went with stainless for the pipes. They should last almost forever. I could have put water pipe on, but to me that just looks really tacky.


A word of advice. When changing engines always measure the gear extension on the engine that you take off. Be precise and duplicate that amount on the replacement engine. Failure to do so may result in multiple engine removals to get it right.

Here is a picture of my 8249.


Tail pipes are too long and the muffler clamps not chrome, but that has since been rectified.

I am a big fan of Onan engines. I tore down the 3000 hour P224 that is on my 24G because it was starting to smoke. I got out my micrometers and measured everything. Apart from the rings, nothing else was worn. It all met factory specs. I micro-honed the cylinders, put in a new set of rings and put it together. It is now good for another 3000 hours.

[daugen]

Bruce and Richard thank you. All of these engines are good, and while I like the "mini-Harley" rump of the Vanguard, the Honda is very smooth, and obviously high quality.
The Onans get bashed for high parts cost, but...if you maintain them, how many parts does one really have to buy?... I love the unique Onan sound. I don't have the skills to do this
but based on availability of those adapter plates, that will likely drive my decision. Of course a nice V4 Wisconsin would be a hoot...but now that's dreaming.
thanks Drew

[RichardTX]

The Onans get bashed for high parts cost...

And the fact of the matter is that Onan engine parts are actually cheaper than Kohler. Price out pistons or a crankshaft for a Kohler M20 and compare that to Onan's price on a P224. Kohler wants $800 for a M20 crankshaft. The last Onan crankshafts I bought cost me a whopping $125 each. Briggs is higher than Onan too.

About the only thing that is pricey on the older Onan's is parts for the Marvel carbs and some of the Prestolite electrical parts. Then again, what do you expect from a company that made aircraft carbs? On the later Onan engines, Nikki 6100 carbs were used. New Nikki carbs are about $125. The starters on the later Onans are made by Mitsubishi. I forget what the model number is but they are used in all manner of things.

[RichardTX]

If you want to sell the B48 engine on that 8199, let me know. I have a home for it.

[daugen]

I'll remember that, thanks
here is a favorite pic of mine during renovation, I call it "fins"

[RichardTX]

I'll remember that, thanks
here is a favorite pic of mine during renovation, I call it "fins"

I call it "will overheat" if run that way.

[daugen]

of course, this was during renovation. Without the shrouds on, I'd cook it, like you said. The fins were a mess, clogged with mud, almost like the prior owner went mudding with it, which I knew he didn't. Likely caused by oil and dirt, the oil from too much blowby caused by that tiny vent filter being clogged. So I cleaned them out carefully, and repainted sparingly. Love this machine, one of my favorites. I've put the newer model muffler on, which quieted it down a tiny bit, and a nice chrome extension completed the job. I think it sounds better, but likely all in my head. If they had put the points on this machine in a more accessible place, like on the single Kohlers, I would probably live with it. This winter I'm going to install Kirk's electronic conversion and see if that helps. Hate to get rid of an engine that works, but when it won't start with stuck points from sitting for a few weeks, it just drives me nuts.

btw, your Onan looks super. The 24G was always the one I drooled over, didn't they put a Subaru engine in that too? A guy locally, who I bought the snowblower for it from, has a 24G with a Johnny Bucket on front, a very nice setup.

[RichardTX]

btw, your Onan looks super. The 24G was always the one I drooled over, didn't they put a Subaru engine in that too? A guy locally, who I bought the snowblower for it from, has a 24G with a Johnny Bucket on front, a very nice setup.

That's no 24G. That is a 8129 that I put a Onan P224 on thus creating a "8249". I have a 24G. I also have a 16G that I turned into a "24GLX" by installing a P224. The LX means Lightweight eXperimental.

I know of no Subaru engines installed on the 4 wheel tractors from the factory.

Stuck points? That is bizarre. I have yet to see that on any engine. I assume they are sticking open. If it were mine I would get another set, make sure that they are lubricated and try that. I would also make sure that the replacement points are OEM and that the point cover is sealed.