A minibike rebuild

Upon learning a doleful story of my pining for a minibike in my youth, a friend of mine, Paul Porlier, plucked this little gem from one of his buddies where it had apparently been rusting quietly for many moons, exposed to the elements, abandoned to a certain death.

The "little gem" was not quite a turnkey machine, but with some elbow grease and some ebay surfing, this little screamer was lovingly restored to its former glory.

I took delivery in August 2001. Motor was seized, missing scads of parts, no brake, cables, chain, carb completely oxidized shut. Pine needles were found to reside in the crankcase, and a Funky rear wheel replacement from a hand truck must have been installed for wheelies at some point.

Minibike as receivedMinibike as received front viewPowerdyne of Pawtucket RI label

It's a PowerDyne Galaxie. Made in Pawtucket Rhode Island. In the 70's? A strippo I think, no lights, no torque converter, no suspension, and a small 2.5 HP Tecumseh. After it sat in my shed for almost two years, Tim and I got down to business. With some sweat and parts procurement, here are the results!

Refurbished Powerdyne minibike

Hot, Blue, and Righteous*

So, what's new? New rims and rear tire. A monster 14 inch diameter Universal tread. Barely fits and boy does it suck down the power. Check out the clearance with the air cleaner. Gulp. Great top end speed though! Original front tire was a bee-otch to peel away from the old rusty rim, but, afterall, it's a made-in-the-USA Carlisle tire and it's in great shape! Seat was scrubbed and it looks great. (I see some people are selling purple metal-flake seats on ebay......hmmmmmm)

Believe it or not, the original engine was salvaged. I took apart the engine and pounded out the piston, sanded the bore by hand with 400 grit, replaced the piston rings, wrist pin, spark plug and ignition assembly with used engine parts from a litter of donated tecumsehs. The original crank journal was sanded and polished, the pine needles and aluminum oxidation were scoured away, and a new carb, air cleaner and muffler were procurred and fitted. The thing ran supah.

2.5 HP Tecumseh engine Clutch side of 2.5 HP Tecumseh engine

The first carb mentioned above was new, but it was the newer "emissions" type model without a choke. (Darn emissions carb). It was difficult to start even with the primer bulb. So eventually I found a snowblower carb with a choke. It's downright amazing how easy it is to start now, and I can get the engine to idle extremely low and smooth. Ahhhhhh.

Color choice: Hammerite Blue paint for the frame, '67 Pontiac GTO engine paint for the engine (Yea, I'll get to the GTO some day, Mr Dunn). It's an amazing color match!

And since I'm ever the motorhead, I decided to upgrade the muffler. The one I fitted was far too garden variety, so I whipped out my trusty Craftsman MAPP gas torch and fabbed up the beauty shown below with some electrical conduit and, yep, a WD-40 can. I brazed the flange and used solder on the "muffler". I think I should submit this idea to WD-40. Perhaps I'll win a prize.

One possible use of empty WD-40 can

Can you say burn hazard?

Minibike with screaming WD-40 muffler

Yep, what a pipe. A one lung-er Harley sound. However, this gem didn't last; it seems Tecumseh engines can generate quite an amount of heat and after about 7 minutes of operation, the "muffler" shot off in a blast of molten solder. I spent a while peeling solder spatters off of the whole backside of the 'bike. So, I brazed everything and also experimented with offsetting the pipes internally to quiet this beast down. Now it emits a nice burbly tone.

This thing is an absolute blast to ride. It's not too zippy off the line, but it wakes up pretty quick after about 5MPH. Hmmm, perhaps an upgrade to a 5HP motor, or a smaller tire for off-the-line smoke shows....

Jenny can just about do wheelies since she's packing 90 lbs less than me.

Here's Tim at WOT...

A spin down the street

Here's a "loaded" PowerDyne pic I found on the 'net:

Loaded Powerdyne minibike

This specimen has a fork with springs, torque converter, and a kick-arse tail pipe, inspiration for my muffler pipe attempt.

Thanks to

Tim Miles who helped out with the rebuild.

Jenny too for sanding the frame!

Paul Porlier for location service and transportation.

Foggy for the chassis donation.

JClark for the litter of motor parts.

*Thanks to Matt for the name suggestion, the ZZ Top tune Hot Blue and Righteous, Tres Hombres album. Vinyl LP. (The remastered ZZ Top albums stink if you ask me, but I digress....)

Visitor's comments

".....Paul got this bike from me and I got your link from him. It looks great and I'm glad it when to a good home. You did what I wanted to but did it way better. Good luck and enjoy....." M.F.

".....Young Tim looks resplendent upon his charge.. with assuredness and confidence at speed......" L.T.

".....my # 1 son thinks you should stretch out the front forks for a chopper look , and a custom mandrel bent s/s one into one exhaust would be sweet, sick and knarly dude....." Bigdogned

".....Do you really fit on that thing? Needs a 10 horse motor. Where are the flame decals?" P.E.D.

".....AWESOME !! you can wash and rebuild my lawnmower any day !! This thing is a gem, very nice, nitrous oxide would help things out tremendously..." B.D.

".....Let me know who gets the first tragic "muffler burn". I remember my first one...right down to the meat...." T.W.

"I was driving down the road one day and found that exact mini bike on the side of the road for $40. I got it and 6 months later... this is what I got...
I made my exhaust with left over scraps of metal and had to make a bracket for it..." J Mosser.

Here's a shot of J. Mosser's 5hp ride: (click for big pic)

J Mosser minibike Powerdyne?


Manufacturers Supply A great source for minibike parts



Willys Jeep CJ3A Forum


There exists a nice set of webpages for CJ3A's. It's got a forum too that caters to both '3A's and  CJ3B's. It's a great resource, and frequented by very knowledgible folks.

1967 GTO Original Owner

These two videos feature an original owner GTO. This car was featured in Hemmings Muscle Cars magazine a couple years ago. Part 2 has inside and outside shots of the owner driving the car. Very nicely done.

Blues Maker

"Mississippi" Fred McDowell. One of the great Bluesman. This is a documentary made in 1969.


Pinstriping the ol' fashioned way. Pretty nice.

MGB Racecar

I've always liked MG's. Watch this MGB lift it's inside tire a few inches off the tarmac when going "'round the bend". Awesome.

Pepsi Throwback

Pepsi Throwback with Sugar!

Pepsi has put out a "limited edition Throwback" version of Pepsi with REAL sugar, instead of high fructose corn syrup which has been used since the 80's. Holy cow there IS a difference; it's WAY better. Find some quick!

Copyright 2009-2022---Dave Miles----Squids Fab Shop