Need an engine...but.

I have a very old walk-behind tractor. This would be VERY handy for my little garden. I also have several
attachments for it including a single bottom Brinley plow with coulter.

Problem is that the engine on it is just plain old and worn out. Carb leaks even after cleaning and replacing
gaskets. Fuel tank sediment bowl will not seal right. It also smokes quite a bit when it is running.

I want to replace the engine, but I keep running into problems. The original engine (as far as I can tell) is
about 3 to5 hp. It has a 1 inch horizontal output shaft. Replacements I find in that horsepower range all have
smaller shafts or have to be mounted too far forward to clear the gearbox. I have a 6.5 hp Briggs engine that I
had as a spare for my tiller, but it simply has everything in the wrong place (most I can deal with) and the
output shaft is only 3/4 inch.

Every replacement I have looked at is either prohibitively expensive or has a smaller shaft. Looking for
suggestions on what might replace it. BTW, already looked at the HF 6.5 hp engine. That would be nice, but it
only has a 3/4 output shaft. Next step up costs too much more.

You dont tell us what that shaft goes into, but there are step up sleeves available for applications like that.

Search for places that sell go kart supplies.

The shaft goes into a pulley that drives the gearbox.

I do not know if they make such a product but is there a sleeve or bushing available to slide over the shaft? Years ago I had a Wisconsin/Robin engine that needed a different type of output shaft and I worked as a welder/machinist at the time. I pulled the crank, cut and welded on a new end on the shaft and trued it up on the lathe then cut a keyway. If you know anyone who works in a machine shop that would be an option.

Well holy guacamole, they do make adapter type sleeves and they are cheap.
https://www.amazon.com/dp/B00T6V3TS4/ref=cm_sw_r_apan_glt_fabc_T3MM1231Q49PMFCWP1A6

Have you tried going the other route of trying to replace the pulley? I would think you could adapt the pulley to the engine easier than matching an engine to the pulley.

Adapter or buy different pulley.
When I can't buy what I want, I make it.
Turn an adapter on lathe.
Or I'll go to Coldwell bearing. Buy a brass bushing with 3/4 ID and turn OD to an inch.

I've made special bushing for cement mixer that way. Had to use 2 bushing and lathe

My recommendation is to get the adaptor that others have suggested. I also recommend getting a HF 6.5 engine which are about 130$ I have used these engines and they are great. For a total of about $150 you will have a heck of a maching! Good luck!

If you do go with a new engine compare the weight of the new engine to the old engine. Most likely the old engine will be heavier then the new engine. If this is the case you might want to add weight in the engine area to bring the balance back to what it was at the factory. I had to do this with a rear tine tiller when I replaced the old engine with a new light weight engine.

https://www.amazon.com/BILING70-Eng...47F/ref=pd_lpo_3?pd_rd_i=B07QY8247F&psc=1

Lots of other available as well. McMaster has some, Amazon has some...

Oh, how I wish I had a lathe! I would have made one by now!

I do believe the consensus is to get another pulley. After turkey day, I will take a ride over to the local McMaster-Carr (I think) store and see what they have. After that, a ride over to the local Harbor Freight. Then, I have to make up some sort of mounting.

The old engine weighs probably around 80 pounds. New ones are more like half of that. But, I do have wheel weights. They are quite heavy. I also think there is CaCl in the tires. Overall, it is a nice outfit for a small garden.

A lathe is something I don't use often

But priceless when you need it
Comes in real handy when rebuilding hydraulic cylinders, polishing rod. 600g puts a mirror finish on the rod.
My lathe is as old as I am , 72.

If you aren't in a hurry to get it might want to check Surplus Center web sight from Lincoln Nebraska.
Most everything they have currently has .75 shaft.
But no guarantee one might show up with a 1 inch shaft.
Happy thanksgiving! DOUG

I have this fabulous little machine shop that solves my problems. They love for me to come in as I break the monotony of large repetitive orders. I have had them gin up some doozies and they get real excited to figure out the approach to the design. Have never failed me over the years.

So the engine shaft goes directly into the gearbox? What make is it?