OutdoorKing Repair Forum Forums Repairs and Maintenance Questions on Engines Questions On Briggs & Stratton Engines What Briggs Motor for Yardman Beetle

Not a simple thing to weld up, easy for the manufacturer when they are all jigged up and held central and square. I would be looking at bolting a weight between the pulleys to compensate for the lack of spinning crankshaft weight. This is not just wack some weight on it, this needs to be done in a professional manner by someone with fitting and machining experience

The one I have here is exactly like the one you show except it is 25mm/1" all the way through, came off a Cox XL Scout ride on, and has the same method of attaching. So if your replacement engine has a 25mm shaft, even with a stepped section it should go on okay. If you did need to make a short sleeve to fit the stepped section that would be a pretty simple job for machine shop to do. I'll take some photos later.

Measurement across my top pulley is 90mm.
Measurement across my bottom pulley is 125mm.
Measurement bottom to very top of shaft is 152mm
Measurement centre of pulley to centre of pulley is 115mm
Keyway is 4.8mm wide
From the top of the shaft to where the bolt tightens up inside the pulley tube is 70mm

Trev, I might be looking for a pulley shortly, a mate of mine has just picked up a Masport slasher which has no motor so obviously no pulley. Until he drops it off here I don't really know except I was told it had been fitted with a vertical shaft motor

Trev, I might be looking for a pulley shortly, a mate of mine has just picked up a Masport slasher which has no motor so obviously no pulley. Until he drops it off here I don't really know except I was told it had been fitted with a vertical shaft motor

NormK type in google 'engine stack pulley' they are all different prices.

Will probably buy one of the ebay motors and hope it has the heavy flywheel.

Thanks Rudes, I'll have a look, not sure what I will need yet. I'm sure the ebay Briggs motor will be fine

Dimensions are all different except for the overall length, Smaller top pulley, larger bottom pulley and different spacing between them. Bummer about that.

Thanks anyway aussietrev.

Met a guy today who came over to look at the bug. He has worked on them over the years. I have had this machine since it was 3 years old. Found out the motor i not the right one. They had a 8.5hp mounted sideways to fit. He said a 198700 series motor? So now trying to find out what machines used the 198700 series, with no luck, but at least it helps. So over this 22mm shaft problem.

I think trying to find an off the shelf fix is not going to happen, something is going to have to be machined up or fabricated. Not rocket science, anything can be done, you just have to find somebody capable of doing it, there are people out there who can do it. Try your local bearing supplier and see if they know somebody who does a bit of backyard machining, they usually do

Yeah but its Kingaroy. Went to buy a new motor today but Briggs don't do an 8.5hp anymore they jump from 6 to 11 and 11 up all have 25mm shafts. The guy said strip the 10hp i have and get the shaft machined. Going to start the strip down tonight and get this thing done.

Ok so it is in Kingaroy, should be able to get it machined for peanuts

lol yeah just moved out here from the rat race. Renting and bought an acre and about to start building. Actually looking forward to pulling the crank out. Done a lot of different motors over the years but never a Briggs. Looks pretty straight forward.

Just as well i checked the 10 and 12 hp motors i have, won't physically fit where they need to be #$@/@#$�@$.

Someone somewhere must have a 8.5hp 22mm straight shaft. They must of used that motor on some type of other machine and not just on the @#$@�@ Yardbug.

Could use the 6.5hp ebay motor, will have a think.

NormK

You might be able to help me out. The 5hp from my Rover Colt 5 fits the Yardbug and Rover made a Rover Colt 8. Is the 5 and 8hp physically the same size motor?. If they are would like to chase up an 8 and get the shaft machined down to suit the Yardbug.

Original smokey, carby problem motor just sitting there with battery and fuel tank removed.

Original motor with 22mm straight shaft not stepped.


5hp from Rover Colt great fit. If 8hp from Rover Colt is physically the same size would prefer to fit the 8.


This is my problem. My 10, 12 and 5hp motors have stepped shafts, 22 stepped up to 25mm so pulley won't slide up


Top of the pulley. They say they cant hold the big pulley end in lathe, it will wobble, can't machine out because cutter will catch on keyway and break, there wont be enough metal left to deepen keyway if they machine out to 25mm, it is a blind hole and can't do, it's not blind it reduces 70mm down where the bolt comes up from the bottom and screws into the end of the shaft


The pulley that is driving me nuts.



Mower is loaded on trailer ready for the tip. Got a lot of use and very easy to work on and never broke a cable. Will try one last thing, phone MTD and find out hopefully what pulley they were using on the 8.5hp version (if it was stepped 22 to 25mm) and if i can get one.

I posted on the other subject post of yours, re the 8.5HP. There is no reason that it cannot be clamped to the bed of a mill using clamping blocks and then run a 25mm facing cutter down the length of the step. Going from 22 to 25mm you are only removing 1.5mm of metal. It looks from your photo you would still have plenty of metal to rebate the keyway that amount which could be done with a square file or use a slot drill to take it down and then just square the corners out. Norm has offered on there to work the pulley over if you send it to him.

Found a really really old workshop locally.
The guy clamped the pulley in the lathe and kept tapping it till it spun true.
He said he could open it out to 1" but the washer inside 70mm down was an issue making it hard to cut the keyway.
He said he could cut the pulley in half do the machining and then sleeve it back together.

The phone rang it was MTD Australia saying their representive has sent me an email. The email had the part number for later model pulley which is 1" and the original engineering drawings for the pulley showing 1" and the pulley is in stock. Wow its ordered and be here in a couple of days.

Thanks for everyone's patience and advice Thanks

There was always going to be some way to skin that cat