Lawnboy powered Canadain Sprocket eh!

[Sprocket86]

Hello to all members.

Here is my latest build on my Canadain made "Sprocket" minibike.
After viewing and reading over another members gokart build (thanks Russ2251) for some insight and ideas, I just
had to do this unique and technical build for myself.

As I have read this is not a simple bolt on ordeal and I like that. I currently have the engine mount being tig welded
and I'm going the machined crank route as I would like to (and be the first I think) to mount up a Comet Tav2.
I think after watching those You tube vids that Russ2251 made, my setup on my mini ike is going to haul the mail!!
The only mods really will be the Tilly HL-334ab carb as I dont think Im going to do the head gasket mod.

After this is all said and done it will be used to power my Sprocket minibike pictured above.
I love Sprocket minibikes and they are another topic on thier own. Sorry for the long first post in years.

Cheers

 

[bikebudy]

Welcome & Best of luck. :thumbsup:

 

[chipper]

This is cool , eh !

 

[lawn-boy biker]

Not known as RUSS2251 on this site.

 

[Sprocket86]

Not known as RUSS2251 on this site.

Sorry about that. Honestly didn't know you were on this fourm.
I feel kinda stupid lol
Are you still building or should I say converting the duraforce engines still?
I loved reading up on your Dual engine kart and Fast Eddies Rupp kart builds, very interesting and Im getting ever so closer to completing my project.

 

[Sprocket86]

This is cool , eh !

Hahaha its what its all "aboout"

 

[lawn-boy biker]

Are you still building or should I say converting the duraforce engines still?

I have about a ½ dozen or so...I think that's enough to hold me for a while.
I currently have 2 karts and 1 mini bike powered by Lawn-Boys.
To my knowledge Fast Eddie never finished his, nor has anyone else.
One guy I spoke to on mytractorforum.com is working on powering a bicycle with a model V Lawn-Boy.

I can remember when most gokarts and mini bikes were powered by 2 cycle engines.
I'm trying to bring back those days.

 

[boatguy]

Welcome to the fun--looks like a great build. A word of caution --where the frame bars meet the front neck of the bike I would re-weld them with Tig. I knew the guy who made these bikes and have seen some break at these joints--usually the top bars.Just trying to prevent any injuries!

 

[Sprocket86]

Welcome to the fun--looks like a great build. A word of caution --where the frame bars meet the front neck of the bike I would re-weld them with Tig. I knew the guy who made these bikes and have seen some break at these joints--usually the top bars.Just trying to prevent any injuries!

Hi there. Really?? I think I have read this somewhere before and thanks for the heads up. I always look down at that section and wonder why he didnt just run the ends of the mainframe tube imto the head tube? So far mine is holding strong and my bike is number #572 if that matters and I dont beat my minibike over rough ground or big bumps. Im worried now lol

Thats neat that you know the guy who made these. I went right to his place to pick my first one up back in 2005 and he had quite the set up and even had a full suspension model but I have never seen one. Do you know why he stopped making them? I have always wondered what happened to the minibike man in the north lol.
I think he cranked out over 1000 units before he called it quits.

 

[Sprocket86]

I have about a ½ dozen or so...I think that's enough to hold me for a while.
I currently have 2 karts and 1 mini bike powered by Lawn-Boys.
To my knowledge Fast Eddie never finished his, nor has anyone else.
One guy I spoke to on mytractorforum.com is working on powering a bicycle with a model V Lawn-Boy.

I can remember when most gokarts and mini bikes were powered by 2 cycle engines.
I'm trying to bring back those days.

I'm 28 years old and my first taste or sighting of any gokart or mini bikes was from books that my dad had on lend from the local public library. This was back in the mid 90's and these books were all from the 60's and 70's, needless to say, my first expeirence is with all this old vintage 2 cycle karts and minibikes.
I would love it if 2 stroke 100cc+ air cooled small engines became mainstream again but I think its just going to you and I and a fiew other members that are willing to go this offbeat power plant route or aka "clone killer" wich btw I love lol
Oh wow over a half dozen, you have been busy and Im sure you have this duraforce conversion downpat now. Have you run into any long term durability issues or anything that I should look out for?
Im pretty sure I have a very solid understanding of whats needed to do this successfully but would it be ok if I asked you questions as go?
I had the option of buying a new Duraforce short block for a good price and if I want this engine to last and be a solid runner for time to come, it would be good to start off with a %100 fresh engine. To think that this engine will be fired for the first time and never see blade of grass is kinda cool to me. As I type this the crank is being machined to accept a 3/4 Tav2 driver unit. Will post pics when I get it back, hopfully by Friday along with the tig welded 6061 1/2 thick aluminum engine mount.

Himm Fast Eddie really seemed to have a solid build on his hands with his twin engine Rupp Kart, heck with those KX 60 tuned pipes I was really excited to see how this was going to turn out. He gave me the insperation to go the machined crankshaft route as I would like to be able to use this engine to power both minis and karts.

 

[Havasu Dave]

I would love it if 2 stroke 100cc+ air cooled small engines became mainstream again but I think its just going to you and I and a fiew other members that are willing to go this offbeat power plant route or aka "clone killer" wich btw I love lol

There are several members here who use vintage two strokes on minis and karts. Generally, the engines are representative of what was installed when the machine was sold which are West Bend and it's cousins, Clinton Panther series, and of course Mac. Also, many of us here are involved with vintage karting.

 

[Sprocket86]

Welcome & Best of luck. :thumbsup:

Hi there and thanks.
Its good to know that other Canadian minibike builders are on this awesome site and I look forward
to becomming more active on here as I love this hobby.
What minibikes or Karts do you have btw?

 

[Sprocket86]

There are several members here who use vintage two strokes on minis and karts. Generally, the engines are representative of what was installed when the machine was sold which are West Bend and it's cousins, Clinton Panther series, and of course Mac. Also, many of us here are involved with vintage karting.

Hi
Hi there.
Yes your deffinatly right about other members having and using two strokes, its just a quiet subject on here.
I have looked through other members picture galleries and wow! Some of you have amazing collections of vintage hardware.
Im also a fan of rear engine vintage karts myself and currently restoring this 62 Dart A bone.

 

[Sprocket86]

Here is a pic of my 1962 Rupp Kart

 

[lawn-boy biker]

Have you run into any long term durability issues or anything that I should look out for?

No issues at all.
Just make every effort to keep the upright part of the mount as short as possible.

Generally, the engines are representative of what was installed when the machine was sold which are West Bend and it's cousins, Clinton Panther series, and of course Mac.

True enough and I've had a few of them. Still have an A-400 Panther which will likely be buried with me.
For the most part, engines mentioned are next to impossible to acquire. Whereas Lawn-Boys are relatively inexpensive/plentiful and are begging to be snapped up and modified for our use.
Horsepower can easily be bumped up with very little effort. No need for billet anything.
Engines are practically bulletproof.

 

[Sprocket86]

Once I upload pics of my engine mount, you will see that it's more than strong enough to avoid deflection under load. So I hope!
but thanks for the input.

I have always wondered how one of those sweet little Clinton A-400 2 stroke engines perform?? and yes if I had a cherry one I would want to be buried with it too! It would be really sweet if china would clone one of these with modern ignition and metallurgy but then they wouldn't be as unique and everyone would have one.

uploaded some more pics. More exciting ones will be posted in a few days.

First pic is my 1983 Tec HS50 that I have slightly modded. Lawnboy duraforce should provide substantial performance increase over this engine.
Second pic is just some frame clean up where the powder coating has started to flake off. Would like to paint the frame a shade of green that would resemble lawnboy colors.

 

[delray]

hey sprocket86 or lawn boy biker, if you ever run across a toro snowblower with a 6.5 hp you could though that in a minibike. i believe when toro purchase lawnboy all they did was modifly the lawnboy engine and made a 6.5hp for the snowblowers. i have work on them in the past. coil went bad on my dads 6.5 engine and i use a coil from a silver series 4.75hp lawnmower. engine comes with a 1 inch keyway crank.........:thumbsup:

 

[lawn-boy biker]

I purchased 2 brand new Toro piston ported snow engines for a very good price from Ebay a few years ago.
Very poor performers compared to the Lawn-Boy Duraforce.
PTO's on both engines are 63/64ths.
The Toro snow engines were built by Briggs & Stratton and are known as R*TEK. At first glance they appear to be Duraforces.
Some R*TEK parts such as flywheel, head and connecting rod are interchangeable with the Duraforce.

 

[Sprocket86]

Piston port v.s reed port induction I think has something to do with it if I'm right Russ?
I think I read that you custom made some carbon fiber reeds and how did these improve performance?

 

[lawn-boy biker]

Piston port v.s reed port induction I think has something to do with it if I'm right Russ?

Generally, reed engines do perform better than piston ported. There are exceptions.

I think I read that you custom made some carbon fiber reeds and how did these improve performance?

Seemed to improve/stabilize idle and engine seemed to have more "snap" throughout the rpm range.