Fabcraft needs to make a bigger version of their "Mountain Mini"
- Thread starter Idcatman3
- Start date
Whoa, cool.
I wonder how that would fit in the mini chassis.
I'm sure there could be issues with that...but who knows. I haven't seen one of these in person before.
http://gorotax.com/all-max-engine-packages.html
I wonder how that would fit in the mini chassis.
I'm sure there could be issues with that...but who knows. I haven't seen one of these in person before.
http://gorotax.com/all-max-engine-packages.html
I hadn't either. A buddy and I were talking about ways to soup up a 120, and he mentioned a big chainsaw engine. That got me looking at little two strokes and then I found these.
Spendy, but so are the Briggs 206s that are used.
Spendy, but so are the Briggs 206s that are used.
clutching that thing should be fun... 11,500 RPM !!!
Those are run in a spec Rotax class. They are spendy because they are sealed and all components are wired and can only be serviced by Rotax reps. Once that wire is cut it has to be re-certified to run in the class. There are 2 other motors that compare one is a parilla leopard and the other is a prd. The Rotax run a traditional carb, the other 2 run a chainsaw type carb. All three make close to 29hp. The Rotax is a PV motor the others are not. The leopard motor is much more robust on the internals including a billet rod.
Sold, but this is about what well sorted leopards go for.
http://ekartingnews.com/forums/topic/for-sale-tag-125cc-iame-parilla-leopard-complete-package/
http://ekartingnews.com/forums/topic/for-sale-tag-125cc-iame-parilla-leopard-complete-package/
Ok, so I got this from a knowledgeable and experienced guy.
If he wants to add anything, he's welcome to join.
If he wants to add anything, he's welcome to join.
Ya, looked at that motor.<O</O
It has a gear box on it so it's too heavy for sleds.<O
Not very good reviews from the motor gurus in the cart world.<O
The other two are motors I'm looking at.<O
Lots of problems though.<O
No way they will work at 11,500 RPM. No torque at anything below 10,000 rpm.<O
They only have a 30 to 40 hr. life span before you have to completely rebuild them.<O
Cranks are not built for CV clutches, so we would need to make a new crank end.<O
Cylinder needs to be completely redone to fix the port timing for 8,000 to 9,000 RPM range.<O
Then we get into building and dynoing the pipe to work at elevation.<O
VES spring testing<O
Ignition timing changes<O
Etc…….<O
All these are being run at 0 to 1500 elevation on racetracks where the temps are 60 to 100 deg. above.<O
It's on my wish list and will likely do eventually, but it is going to be A LOT of work.<O
Be sitting down for the price when done.<O
May have to take out a second mortgage.<O
Guys think these minis are expensive now, just wait till they see what it will take to make a 2 stroke work in one.<O
But they will be really cool!<O
I
If someone had the tools, knowledge, time, and money it seems you could cut something like a polaris 500 engine (i envision a liberty engine since the older fuji's were monoblock) in half to make a single cylinder 250. P85 clutches look too big to fit under the hood of a 120 so maybe machine a JR racecar primary to fit on a tapered crankshaft...
Building a pipe long enough to get the power where you need it and still fit under the hood might be a challenge. But at the same time the engine would make enough power that you could probably just dump an untuned exhaust into a muffler and still make more than enough to have a real rocketship mini.
It seems like then you could use mostly off the shelf parts for the rest. The 500s use a wasted spark ignition system so that makes it easy...
I've had this idea for years but dont have the rest to make it happen...
Building a pipe long enough to get the power where you need it and still fit under the hood might be a challenge. But at the same time the engine would make enough power that you could probably just dump an untuned exhaust into a muffler and still make more than enough to have a real rocketship mini.
It seems like then you could use mostly off the shelf parts for the rest. The 500s use a wasted spark ignition system so that makes it easy...
I've had this idea for years but dont have the rest to make it happen...
We've toyed with the idea. To build our 1500 triples, we end up with enough parts left over to easily build a single 450. Pipe is easy, ignition is easy. Fitting it under the hood is hard. We have also though about doing the same with the Cat 570 fan. The thing I don't like about that idea is the clutch. Fitting it all in the mini chassis would be hard. These TAG motors are already a 4-bolt mount, just like the stock mini motors.
I'm not sure I agree with some of what your source said Scott. From what I can see, this does not have a gearbox. They make one that does, but it's not this one.
They also make a lower power version (~20 hp) that would still be a rocket, but only turns 8500 RPM. That version also doesn't have an exhaust valve. I don't know about the clutches, but it comes with a centrifugal dry clutch, to a chain, like they do stock. I don't know much about those, but I would think it shouldn't be too hard to either use that, or build a small adapter that would bolt on where the sprocket goes to put a CV clutch on.
40 hours for a rebuild doesn't actually seem that bad to me. On a full size sled, 40 hours, at 40 mph is 2000 miles. Many people do rebuilds that often on the full size sleds.
I just wish I had enough time/money to look into this myself. I've got lots of ideas, but the whole "need to keep my job to make money" thing really gets in the way.
I'm not sure I agree with some of what your source said Scott. From what I can see, this does not have a gearbox. They make one that does, but it's not this one.
They also make a lower power version (~20 hp) that would still be a rocket, but only turns 8500 RPM. That version also doesn't have an exhaust valve. I don't know about the clutches, but it comes with a centrifugal dry clutch, to a chain, like they do stock. I don't know much about those, but I would think it shouldn't be too hard to either use that, or build a small adapter that would bolt on where the sprocket goes to put a CV clutch on.
40 hours for a rebuild doesn't actually seem that bad to me. On a full size sled, 40 hours, at 40 mph is 2000 miles. Many people do rebuilds that often on the full size sleds.
I just wish I had enough time/money to look into this myself. I've got lots of ideas, but the whole "need to keep my job to make money" thing really gets in the way.
M
You should look at the Hirth F33. It weighs about 35 lbs and makes about 28 hp. AND you can get it with a 30mm, 1:10 taper PTO (stub shaft drive), so clutching options are wide open ... Oh, and the operating RPMs are about 6500. This motor was built for ultralights, so it's normally configured with dual CDI and is designed for free-flow air cooling, but Hirth also makes a variation of the F33 for a waterpump company which is configured for single CDI and has full engine shrouds with a fan and recoil start (perfect for a sled application). New, the F33 runs about $3 grand ... and that is the one down side.
Here's a couple links for more info:
http://en.wikipedia.org/wiki/Hirth_F-33
http://www.recpower.com/F-33%202%20cycle%2028hp.htm
http://www.hirth-motoren.de/en/engine-f33-b-bs.html
NOTE: See data sheet from the last link for detailed info.
Here's a pic of the single CDI fan cooled version:
Here's a couple links for more info:
http://en.wikipedia.org/wiki/Hirth_F-33
http://www.recpower.com/F-33%202%20cycle%2028hp.htm
http://www.hirth-motoren.de/en/engine-f33-b-bs.html
NOTE: See data sheet from the last link for detailed info.
Here's a pic of the single CDI fan cooled version:
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450
IT seems to me like the coolest thing to do would be to take one of their 450's that are left over, and build a kids snowmobile around it from the ground up, new chassis and all. Find a chassis size that is right in between the full size and the 120. That would seem to be perfect for the kids right around 8-13 years old.
IT seems to me like the coolest thing to do would be to take one of their 450's that are left over, and build a kids snowmobile around it from the ground up, new chassis and all. Find a chassis size that is right in between the full size and the 120. That would seem to be perfect for the kids right around 8-13 years old.
Something like a timbersled kit on a small 4-wheeler frame is what I was thinking. I wish I had more time to tinker with this stuff.
The 4-wheeler would get the rider forward position, and hopefully easy enough to transplant a bigger engine into.
The 4-wheeler would get the rider forward position, and hopefully easy enough to transplant a bigger engine into.
The junior Max 125 looks to be a better fit RPM wise. And 20.4 HP will still haul the mail with a CVT belt drive.
http://gorotax.com/junior-max.html
And with it running a centrifugal chain clutch it MAY be a direct swap to the junior Drag racing CVT Primary for a belt drive? Although being Rotax it is likely Metric rather than 3/4" on the shaft.
The Hirth engine with the standard crank shaft end is sized such that the JR dragster clutch could be easily Machined to fit the standard Hirth taper.
http://gorotax.com/junior-max.html
And with it running a centrifugal chain clutch it MAY be a direct swap to the junior Drag racing CVT Primary for a belt drive? Although being Rotax it is likely Metric rather than 3/4" on the shaft.
The Hirth engine with the standard crank shaft end is sized such that the JR dragster clutch could be easily Machined to fit the standard Hirth taper.
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C
Sno Sport or Scoot ... no need to build a frame with rider forward setup as Yamaha had it nailed 20 years ago but then dropped the ball! The stock 125 Sport long tracked will pull 50 km/h all day long and is way more capable than the minis.
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