So you wanna go diesel eh?

The first question Im asked regarding diesel engines is if its even possible for their tractor. Most follow lineage in design to craftsman lt thousands and murray select / widebodys. Vertical gas engined ones. Ive never seen a vertical shaft diesel so alot of mods are needed to give you power at the tires. Of course using an horizontal engine.

When people get the idea to convert their older deere or roper or sears to diesel, they want a strong, torquey, simple to install engine. I tell anyone to go with chinas yanmar clone. These are generally 10hp, ohv, 406cc, single cylinder, air cooled, direct injected engines, some with glow plugs, intake resistive heaters, and electric start. Price ranges from 500-800$ in canada and the u.s. Anyway, but it is possible to find them for less on kijiji/craigslist/ebay.

First change thats gotta happen to your tractor is you need a larger bolt spacing. These engines have a bolt pattern of I believe 11.75x9.25 or some weird dimension like that. Every chinaman builds his differently but thats the idea - bolt patterns bigger.

Second is you need to figure out if your clutch junk will work with the different height pto shaft. I know its higher but not by how much more. The engines in their generic form have 1" straight keyed shafts and I don't remember the length.

Once your clutch crap is on and turning you need to be able to control the engines main functions; start/stop, rpm adjust, and optional equipment like glow plugs and stuff. Starting is relatively the same as in a gasser, but these engines have their own solenoid. They have positive (thick wire direct from battery) wired to the starter, negative to the engine block/tractor frame, and a second smaller positive (switched) going to the start solenoid. Its just like a car starter where the solenoid lifts the gear, not a bendix drive.

In a diesel, rpm is varied by injecting variable amounts of fuel. More fuel=higher rpm. No fuel=stops engine. So a speed adjustment system needs to be incorporated into the kill system. Like a lawn tractor that is shut down by moving the throttle all the way down. In a mower not destined for grass cutting, its not easy to set up turn key start/kill plus accelerator pedal. The design Ive found to be genius is courtesy of FearlessFront. Who uses it on his new diesel sears ss-16 suburban diesel conversion. It uses the dash throttle lever to set minimum engine speed with the pedal released. IE high idle, or kill. It uses two cables going to the throttle linkage on the engine. One being the dash cable (idle/kill) the other pulls the linkage to max (3,600rpm, governed). This has proven to me the best system for controling speed on a diesel and so I believe it should be the only one used, unless you want constant, dash control only. Im not clear on the parts used or exact layout of his engine... Reply to this with pics and Ill do what I can to help you with your particular setup. Best of luck! Reply with comments/questions.

Umm.. Wow, that is one big wall of text.  Please edit and use paragraphs, be much easier to read.

Looks like some good info.

Most here don't have diesels, due to cost.

That was typed on my phone... Editing tools are limited as you can imagine.

Waiting for laptops to go on sale since my dream machine's hard disk failed.

you can import vertical shaft diesels from china, but it cost about 1k in the end with shipping and all, but on the pluss side they have a 26 hp v twin diesel

Yup had one, its just the 406 with another set of cams and a second cylinder. Mine was a 20hp horiz.

Thanks for that post, I've broken it up into paragraphs for readability. A few comments-

The Yanmars are great engines, and in terms of popularity, the clones are generally cheaper and more accessible. That said, they are still relatively pricey and the verticals are tough to get ahold of. I dream of getting an oil-burner to power a project with.

It has been my experience that manufacturers (even Chinese clone producers) do tend to stick to some industry standards when it comes to bolt patterns and shaft lengths. Unless you have personally examined several examples, I wouldn't be so quick to suggest that they all "do what they want". A crate OPE engine is made and marketed to repower existing equipment- and it really would hurt sales to deliberately market an engine that requires yet more custom work to retrofit into something. It's very likely that all these similar Diesels share a common bolt pattern amongst them, even if it is not the common gasoline engine equivalent pattern.

I have indeed seen a few Diesel mowers on the market as of late, but they add further expense to an already expensive new machine. Let's face it- not many of us at all have the budget for such things, and it sure doesn't take much cruising of the forum to discover this fact.

That said, thanks for the info. Oh- and for anyone wanting to google for more info- that wonderful Yanmar (horizontal) is model # L100.

Well, I gotta say a few things about that original post, which until now I forgot I made. First off, thanks to Doc Sprocket for organizing it and making it a little less cheap novel-like.

At the time I typed that out I was hospitalized with mononucleosis [so naturally I'd use my data for atltf...] Got bored and remembered something to do with my 406cc diesel and my craftsman II. So I went on a rant about diesel conversions and typed that whole thing into my little Samsung phone. So proper formatting was not my biggest thought. If you're willing to sift through the garbage within it, there is some useful info, particularly concerning the throttle setup [WAY TO GO FEARLESS ON THE SS-16!].

I'm all fixed up and home now and would be glad to answer anyone's questions about their diesel setup. Or just questions about diesel engines in general. I don't just work on yanmars and kubotas.

Glad to hear you're doing better. I just did a stint in the hospital myself... Yecch!