Topic: Cat slingshot minibike ride report.

[Don R]

 It has a 3 hp Briggs, I didn't have the points so put on a left over 5 hp jr dragster coil, it didn't work so I got a special coil off ebay for the 3 hp Briggs made to eliminate the points. I needed to extend the bolt holes a little, did that, and got it mounted but it doesn't make a spark either even with me holding the plug wire.
 Any Briggs and Stratton guys out here?  I really don't want to put a Harbor freight motor on it, but when the magnet goes past the coil, how can it not spark?
 I see a few B&S engines on lawn edgers for sale, I'm tempted to buy one and rob the motor off of it.

[Don R]

Apparently, it needs a one-magnet flywheel and not a two-magnet flywheel.  Per youtube.  A guy on youtube showed an early Briggs and suggested a part number for the one magnet flywheel. I spent the $51
 on Ebay to get it. I'm weary of the F' around and decided to find out.  Lol.
 A guy 30 miles from here has several running engines $80 for all, they are various sizes and HP and surely have the part I need but then I'm dragging home all of his junk too. I'm drowning in Honda junk already.   

[Don R]

 Next up throttle linkage, I think I'll get all of the mini bike parts in one place also.

[Stev-o]

Next up throttle linkage, I think I'll get all of the mini bike parts in one place also.

Did you sort the ignition problem? When I needed a Briggs motor for my son’s first mini bike, I ended up buying an old reel mower that had the exact replacement engine. Put a new plug in it, fresh gas, and it fired right up!

We had a reel mower, Yardman[?] and fairly certain it had a Briggs motor, they were the best. 
I learn to cut grass with it, was a young boy but later on made some pocket money cutting lawns.

[BenelliSEI]

Next up throttle linkage, I think I'll get all of the mini bike parts in one place also.

Did you sort the ignition problem? When I needed a Briggs motor for my son’s first mini bike, I ended up buying an old reel mower that had the exact replacement engine. Put a new plug in it, fresh gas, and it fired right up!

We had a reel mower, Yardman[?] and fairly certain it had a Briggs motor, they were the best. 
I learn to cut grass with it, was a young boy but later on made some pocket money cutting lawns.

I think it was a Yardman. Self propelled too.

[Don R]

 I should get the new flywheel today, I'd like the carb governor to work since the little ones will end up riding it. It's missing a lot of the controls.

[Don R]

 There's no chance of fixing the governor, it was missing too many parts already. I found my B&S manual.
 I did get the new flywheel and it does now make spark with the jr dragster coil. That's a first in 15 years or so on the shelf, I may split the chrome wheels and de-rust them. I'm not sure that I want to re-chrome it all, it's a little too far gone for a numbers matching resto but I did find the repro decals for the front end and may get a vintage Briggs decal for the fan housing.

[Don R]

 Suddenly it has no spark again, even with a new flywheel and coil. I got a new throttle, brake lever, cables, kill button and a Honda seat from a member here, Besides the spark issue I think the compression is too low. My latest plan is to steal the old briggs engine off of their indy car go kart. It's so low it's unusable anyway, they have no pavement.

[Don R]

 We re-cycled the go kart engine onto the mini bike, hooked up a couple things and sent it! The third lap of the yard it spit off the old chain. It's hard to steer but the old tubes took air and the relatively new clutch worked great once I turned it bass akwards on the shaft.
 I decided to forgo the restoration and just make it run with patina that can't be faked L0L!

 The controls are brand name parts from an older company, Azuza? They are pretty but really are draggy and catchy. I'm not sure if it's the levers or the cables.  A member donated a Honda seat, it's a little thicker so I might wait to see how the grandkids do on this seat height.

 I took a late afternoon rip through the yard, about 10' off the sidewalk it spit off the old chain, I put on the new one, it was surprising how much wear the old one had, I held them side by side you could see it. And yes, these cables are crap.

[BenelliSEI]

Nice work! They’ll love it.

Warning: you’ll be building bigger bikes before you know it!

[Medyo Bastos]

We re-cycled the go kart engine onto the mini bike, hooked up a couple things and sent it! The third lap of the yard it spit off the old chain. It's hard to steer but the old tubes took air and the relatively new clutch worked great once I turned it bass akwards on the shaft.
 I decided to forgo the restoration and just make it run with patina that can't be faked L0L!

 The controls are brand name parts from an older company, Azuza? They are pretty but really are draggy and catchy. I'm not sure if it's the levers or the cables.  A member donated a Honda seat, it's a little thicker so I might wait to see how the grandkids do on this seat height.

 I took a late afternoon rip through the yard, about 10' off the sidewalk it spit off the old chain, I put on the new one, it was surprising how much wear the old one had, I held them side by side you could see it. And yes, these cables are crap.

Great job! Is that a 5hp engine? Does it have a scrub brake?


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[BenelliSEI]

……and then you need more of them!

[BenelliSEI]

And then bigger ones too! It’s a slippery slope.

[MauiK3]

This looks like the opening bid prior to a long game of build bigger, faster.............!!

[Don R]

  It's a 3 hp Briggs, and it has an actual drum brake. Sort of.

 There's a Honda XR70R waiting for the first one that can ride it.
 
  The battery powered J-D gator ride on toys spoiled them, they only know two throttle settings, on and off.

[BenelliSEI]

  It's a 3 hp Briggs, and it has an actual drum brake. Sort of.

 There's a Honda XR70R waiting for the first one that can ride it.
 
  The battery powered J-D gator ride on toys spoiled them, they only know two throttle settings, on and off.

All good fun. Enjoy!

[seanbarney41]

Don, you mean there actually is other throttle settings?

[RAFster122s]

With a small displacement motor and heavier rider they will be using full throttle a lot, especially with any terrain. But if they are lightweight, then they might get some speed.

[Don R]

 They are lightweight, it isn't running it's best yet but seems to run better the more I ride it. I can see where we might need the comet torque converter. We had the billet version on our first jr dragster, I finally made enough power that the engine rolled the driven clutch over the cam and unloaded the driven pulley.

[Stev-o]

Time to get my minibike running again...

[Don R]

  I went the rat bike route and made a clutch cover out of a metal waterbed frame bracket and an old license plate. It's running worse so I ordered a replacement carb from ebay. It might also be time for an oil change since it sat so long.

[Don R]

 It was running rough, so I bought a new carb for $15 off of ebay. It looks good but didn't fit the gas tank or the engine, I guess my 3 hp is too old. I looked at the fuel pump and it looked the same, so I robbed the diaphragm and check valve from the new carb, found a tank gasket in my old engine gasket set, cleaned and re-assembled the old carb.
 Wish me luck, I removed the old seat too and now it's junk so the Honda seat will be going on it.

[RAFster122s]

Hope your Frankenstein carb parts create a running bike for you Don... Good luck

[Don R]

 There's a bolt on the carb that's nearly impossible to turn, It's a 3/8" and I was able to get one flat at a time with a 90* offset 10mm. The newer engines have that bolt offset further away from the carb body.

[Don R]

 I gave up and bought a new predator engine. Only 79cc though, if it won't pull the kids I'll get a jr. dragster billet Rhino for it.

[Stev-o]

Don don don, only 79?!   The 212 is only $149....

https://www.harborfreight.com/65-hp-212cc-ohv-horizontal-shaft-gas-engine-epa-69730.html?utm_source=google&utm_medium=cpc&utm_campaign=12188110244&campaignid=12188110244&utm_content=123857267664&adsetid=123857267664&product=69730&store=&gad_source=1&gclid=Cj0KCQjwr9m3BhDHARIsANut04YQkcAF_9WV82SYc8zO0H4Vgq1NLSokjYGFOAQDXXAE3eBENV5DkBEaAkqJEALw_wcB

[RAFster122s]

Steve is making a murder cycle for the grandkids with 212cc, gotta stop as well as go. Lemme at RevZilla played with these kind of cycles several years ago and I think they dropped a Predator 250cc motor in one. Lemme is crazy though...

[Don R]

 I saw it and looked for a while, The 3hp when it was running scared the grandma half to death. We'll give it a try with the little motor. and the XR70R will be the step up.

[grcamna2]

 

[Stev-o]

  The 3hp when it was running scared the grandma half to death.

Understood....

[Don R]

 I have it ready to go except the 5/8" to 3/4" clutch adapter sleeve which is due tomorrow. I got the little motor on, the Honda seat bolted on, it starts and runs. Kill switches wired, etc. Hopefully it also stops good enough.

[Don R]

 Success! The two small grandkids rode the minibike today. We began with them rolling it downhill with no motor, next we started it on flat ground. The cheapo brake lever keeps loosening from the handlebar, and they are used to a quad with a thumb throttle but all in all it's a success.
 Both were a little overwhelmed and found it difficult to turn, so do I. I got them on the Honda XR70R, they didn't ride it but they are nearly as close to touching the ground on it. Next spring for sure.

[grcamna2]

Success! The two small grandkids rode the minibike today. We began with them rolling it downhill with no motor, next we started it on flat ground. The cheapo brake lever keeps loosening from the handlebar, and they are used to a quad with a thumb throttle but all in all it's a success.
 Both were a little overwhelmed and found it difficult to turn, so do I. I got them on the Honda XR70R, they didn't ride it but they are nearly as close to touching the ground on it. Next spring for sure.