Repowering 8199G

[daugen]

Richard, I've had to take a wooden dowel and gently tap with a rubber hammer on the points case, and that usually worked. Come to think of it, last time it was serviced they replaced the pushrod along with the points, and I've not had the problem since. Hmmmm.

And....my bad, it was not a 24G I saw with a Subaru V twin, but rather a 20G. Found the picture, too bad I didn't get one from the rear. Sure liked his Johnny Bucket. I bought this guy's snowblower for my 8199G.

btw, I took one ride with the chains on, scratched the heck out of my driveway, took them off, built a weight box with 300 pounds in it, and it ran marvelously.

 

[RichardTX]

Chains will scratch a driveway but when the snow gets deep, nothing beats their traction.

 

[daugen]

well....I may have done myself in here yesterday. Last mow job of the year, cutting down a lady's "wild meadow", i.e. messy weed patch, and I got into a large area of what I think is milkweed. It was like snow all around me, and I didn't think much of it, dumb me, until I started smelling something and shortly thereafter the engine died. To my serious dismay, smoke is pouring out of the engine, everything is clogged tight with the cottony fluff from the plant, and I really overheated the engine. The gasoline in my clear gas filter was boiling...I blew it all clean with my portable blower, and thank goodness nothing lit off. Let it cool down and would not start, though it spun freely. Expect I cooked either the condenser or the coil. Will pull all the engine shrouds and make sure there isn't any junk in there, which there sure wasn't before I started. Feel bad breaking my machine, not its fault but mine, but with the engine out of sight back there, I just didn't see what was going on nor did I expect it to clog that quickly, in under an hour of mowing. Air cleaner clogged too, with a pile of seeds in one corner. But the clogged intake grill was what did me in, no air getting to the engine so no surprise it cooked. Hopefully I didn't screw up the head, but it turned over fine with no strange noises. Going to replace the fuel lines just in case, can't imagine that kind of heat didn't damage the ones right on the engine. Bummer.

 

[hawkeye08]

I've had a couple of coils go out on my Onan engines on my Gravely riders from getting too hot I expect. Not cheap, around $100 IIRC.. I have a Gravely 816S that I replaced the original Onan with a newer P18 several years ago. It was very expensive for a new engine, never heard of craigslist or ebay back then... It died (will not even turn over) this last summer while pulling a sprayer... I did not have time to deal with it so walked home and got one of the other Gravely riders to finish the job. Reading this thread reminded me that I need to have a look at it and figure out what is wrong... I have 3 Gravely riders, I'm going to move some parts around, end up with two that run well, then sell the 3rd one with a loader.

Hope you find out good news on your cooked engine. Perhaps a digital gauge from a racing kart would work for you. I had a kart 20 years ago that had rpm and temp. A single wire wrapped around spark plug wire for RPM, temp was a thermocouple thing that was like a washer under the spark plug or one of the head bolts, I don't remember which...

 

[daugen]

I hope to get the details today, but the dealer called yesterday and said they got it running, after installing Kirk's twin coil and electronic conversion kit, so it must have been, as I sorta expected, an electrical melt down. Not sure if they took the head off, but it appears that some electrical part acted like a thermal fuse and died for my sins, thankfully. When I get the Gravely back, I'll take pics of the conversion and post them here. The coil is shaped totally different so I'm curious, to say the least, how they installed it.

Hawkeye, I've seen, somewhere, the spark plug heat sensor, and wasn't sure it was what I needed. Sure would like something that bolted into the top of the head, but maybe that spot is as good as it's going to get. I do have the tach/hour meter with the wire around the spark plug btw, it works fine, though seems a little slow in reaction time. I am rebuilding an old CC 125 and got the analog tach for that, boy would I like one of those on the Gravely. And a temp gauge right next to it...and yes, an overheat light/buzzer would be smart too.

After this little learning experience, I'm going to try to rig up an open mesh filter that attaches to the rear engine guard, and that hopefully will collect some of the chaff flying around. Not a lot of space in there, but if I removed the stock
screen wiper, I might be able to rig up something helpful. Plus maybe an electric fan too... good winter project.

 

[daugen]

a tardy update. It runs fine with the new ignition system. No backfiring or weirdness, but still rolls at idle.

I've hunted around the internet as much as I can, and have seen two or three engines put on the back of Gravely tractors.
What interests me is the Subaru V twin, 23hp since it seems to be more compact than others. Also, I like Subaru as an engine co.
Honda too, a nice 690 back there would do, but I always see if the US stuff is available first. So here's Kohler's best EFI:
Kohler Engines: Engines: Command PRO EFI

none of which look like they could remotely fit, adapter plate or not, without at least ditching the Donaldson style filter.

but while pondering this page, I wondered...just how much hp could the Gravely take? I have rugged HDAP tires on the back, and they
can put the hp to the ground. I know the riders went up to 24hp. I wonder what the design could reasonably take, understanding that more hp
might reduce clutch life. But the mechanical part seems very robust. As is the rear end. So how high could we go? 26-28-30 hp? I wonder who
has tried...

 

[daugen]

I have a Gravely 816S that I replaced the original Onan with a newer P18 several years ago. It was very expensive for a new engine, never heard of craigslist or ebay back then... It died (will not even turn over) this last summer while pulling a sprayer... I did not have time to deal with it

I would be very interested to know why a low hour Onan conked out on you. Was this a winter project for you? Drew