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Discussion Starter · #1 ·
I have purchased a 74 model 70 with no engine.I have a 5 horse briggs I would like to put in to be able to just drive around. does anyone have any pics of how to install a briggs engine in this and the belt route. I believe the belt must twist from the engine pulley to the next pulley to make it work.Also need to know how low the engine pulley sits under the tractor. I would really appreciate some help.
 

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Steve first welcome to WFM. That is the good news. Nothing really fits a 60 or 70 except a Tecumseh. Having said that I will show some picture of my 70 with a Briggs 6.75 engine. First you need a vertical shaft engine to make it work. You have to do extensive modification to the engine mounting plate to get it fit. More than just drilling new holes. The engine needs to be moved forward about one inch to clear the clutch/brake pedal shafts. This requires a longer forward belt to fit depending on the engine pulley size. There is no way to use the factory PTO. You need an engine with a heavy flywheel designed to work without a blade on it. My engine is a rope start. If you have a horizontal shaft Briggs there is no way to get the belt from the engine to the transmission without cutting up the tractors frame. There are two belts in the drive train and you need to have the second belt stay in place or you will have major clutch rework. If you are good at fabrication, cutting, welding, modifying etc. it can be done. Roger







 

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Discussion Starter · #3 ·
Thanks roger. For what reason does it need a heavy flywheel I have had my engine running on the bench with nothing on it. Does that mean it will work for me? Does the base of the engine sit at the same height as the tehcumsei or does that depend on what pulley I use.
 

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The engine in mine is from a pressure washer which came with a heavy flywheel to make it run. Do you have a picture of your engine you could post? That would clear up some questions for me. In my case the crankshaft was shorter than the Tecumseh and only had room for the drive pulley. I didn't plan on using it to mow with anyway so it made no difference to me. From the pictures my Briggs looks like it fits the same but it doesn't even come close to bolting in. I had to cut the original engine base to fit the oil sump in the engine hole and them had to add metal to the outside of the base so I had something to bolt the engine to. I have between 25 and 30 hours of fabrication in getting the engine to look like it belongs there. The picture of the tractor with the black engine is the stock Tecumseh that came with the tractor. Unfortunately it didn't start most of the time. The other pictures is the cart I pull with the 70 for yard cleanup. Roger
 

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Discussion Starter · #6 ·
Its a Briggs quantum 5 horse. I beleive it is likely for a push mower it was given to me brand new never used. How does the heavy flywheel help? Is it just to keep it running with little load on the engine?The engine does run on its own on the bench.
I work in a machine shop so the fabrication part is no problem. Guess I will look for another engine.Also is there a pic anywhere of how the belt runs from the engine to the next pulley and is there anything there to help it from falling off?
 

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Discussion Starter · #7 ·
Hey roger did your engine have a long shaft or was it short. I have fount a couple small horse B&S engines from pressure washers but they have a short round shaft about a inch long with a small hex shaft at the end. I`m wondering, one is a 4 hp b&S quattro would the fly wheel fit my 5 hp quantum
 

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Discussion Starter · #9 ·
Thanks Roger . I think I might just go ahead and order one like yours this way I know it will run for me.Do you happen to know what you used for a pulley or have a part number for it. I appreciate all your help
 

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The pulley I bought a Northern or Tractor Supply Company and it is for a 7/8 inch shaft and the same diameter as the factory pulley. I wouldn't necessarily recommend that short a shaft engine as it is none to long. If you can get one with a longer shaft it would give you more fudge factor to make it work. I would also see if you can find an engine with electric start. The manual rope always works but that means every time you shut the tractor off you need to go through the starting process as you can't start it from the seat. SEW has other engines in that 12**** series that have more options and still have heavy flywheels. The reason I bought this engine is it was $50, it ran and was on a pressure washer with a bad pump. Roger
 

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I think the crankshaft is to big in diameter. Maybe in a 100 which was designed to a Briggs 8 HP. Even that was an odd engine in that the crank was stepped from the standard Briggs 1 inch on the top to 7/8 inch where the clutch fit. Roger
 

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I have an 8hp out of a rear engine rider 68 in mine.

Its bigger than Rogers push mower/pressure washer engine. Larger displacement and larger dimensions.

Took quite a bit of reworking to fit, new engine plate (solid mounted), modified brake and clutch linkages, new pulley, different belt, dont have a pto clutch any more.
 

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My L/60 Custom uses an 8 HP Briggs from an R72 RER.



It took some trimming & as Mike said, no PTO.



My 70 I has a 12-1/2 HP Briggs from an MTD "Yardman". I cut the engine mounting plate from the MTD & welded it into the 70 frame.





More frame work than the 60 & smaller pulley to clear the steering. Again, no PTO.



Lowell
 

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Very nice work Lowell! I HAVE LIKED those two projects of yours! Creative of you using the engine mounting plate from the MTD!

Sorry I missed your trail ride this year, maybe next...

Football season you know! We have season tickets for UNI since my wife work there that is a priority now! She fed the football team before the game on the day of your trail ride!

So many things to do and so few days to do them!
 

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Very nice work Lowell! I HAVE LIKED those two projects of yours! Creative of you using the engine mounting plate from the MTD!

Sorry I missed your trail ride this year, maybe next...

Football season you know! We have season tickets for UNI since my wife work there that is a priority now! She fed the football team before the game on the day of your trail ride!

So many things to do and so few days to do them!
 
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