Newby to uas not karting need advice

Shame we're not allowed to run the Banshee engine...

That would be sick, I've seen some banshees run in the mid 5 second range at the drag strip(1/8mile) destroying hayabusas and other big liter bikes! You can make a lot of power with stock size parts inside.
 
I'm with Jack go with a 2- Stroke, just jump on I-81 head for Lynn Haddock's tell him you want to race UAS he will take care of you. It's not that far sure he has something to offer, get the rules off the website ,read them well, if you do not understand something just ask here.
 
I have seen several 450MX engines cheaper than what you would spend on a competitive unreliable 420 Clone. Guys around here are finding complete bikes going for less than $2000.

The key word is used....
From what I've seen, new Jawa is $3750 and $500 for the carb. That's not awful for a new piece that is very near the top of the HP scale.....and best of all, it was built and designed for oval dirt speedway racing.

There are complete Jawa motorcycles for $3500 and you can sell the roller chassis. That's for a piece that makes nearly 20 more hp than a 450 MX engine......and you don't have to fool with water.

At those prices, which is way less than a new 450, I wouldn't be surprised if someone like Seay couldn't be talked into producing an engine mount for it.

Mike
 
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By the way, I have a friend with an 08 KTM 450SX for $1900. He wants a new 300. It won't last long so... nothing wrong with it. Sell the suspension and wheels on ebay and have $700 in it.
Mike
 
Ok got some info from a mx buddy he said he could find me some engine relitively cheap now I need info on setting up jackshafts and gutting transmissions I am pretty mechanically inclined I've done a lot if fab work in the past and have access to a lathe can mig weld as well and have access to a tig anyone have pics or info
 
You should try to get a hold of Justin Westerfield, he lives in Indiana, I think, he took the guts out of the tranny and put a shaft in the tranny case that was pretty cool and very neat looking. I would think he might still have some pics that were on the Pre-Crash Bob's site. Good Luck Man.
 
It you're going 450, leave the trans in, much easier. If you're going 250; I'd consider running the Taft cases if you're going transless. But, personally I'd probably just stick with the trans even in the 250 works just as good, less wear and tear. As everything is made for the engine. Less hassle I think, rebuilding clutches and jack shafts and all that gets expensive. All you have to do is change he oil and filters and occasionally rebuild the wet clutch.

Most argue you lose too much power, but unless you're running on tracks the size of Carnesville or something like that. The 450 with trans have enough HP. Not to mention the power to weight ratio with rider isn't all that much different.
 
The bigger issue with converting the engine to kart specific is getting the mass lower and getting rid of the MX clutch system, you have to adjust your driving for engine braking with the tranny, ( just a matter of seat time,) and what ever you do if you spin don't forget to pull the clutch lever in. Converted engines just act like kart engines that's the biggest difference. you will drop 15-20lbs off the engine weight also, they all make huge HP and it makes no difference to me as long as you come race.
 
A common modification in Micro 600's is to remove 1rst, 4th, 5th and 6th gears leaving 2nd and 3rd. Benefit is less friction/stiction in the tranny. Maybe the flywheel effect of the clutch could be beneficial in lower traction conditions.

DK
 
Some people advocate leaving 4th-5th gears in as the closer to 1:1 ratio puts less stress on the teeth. Or so the theory goes.
 
Its a little unsettling when you lift and the rear tires break traction. Just something guys have to work with or around. Kart systems are the way they are for a reason. Other wise we'd have been using shifter karts along time ago. Again jmo. I'll take racers with any combo. Its all good.
 
90% of the time the normal kart clutch wouldn't disengage anyway. But, when I started backing my 450 in, I turned my fastest lap times. Just enough to set the kart in the corner, and hammer it out. Maybe it comes from running dirt cars previously but this never seemed to hurt me.

When I had the most problems with mine was not being able to get on the throttle coming out. Which that night was a weird night and the kart was all over the track regardless of how I ran it in the corners.

I will say this, and some are running "rekluse" clutches in their MX engines. Does the exact thing a kart clutch does but still maintains the ability to manually clutch it. I run something else though, I have a road racing slipper in mine. I've never had it slip yet, but I think it lacks the grip on dirt to successfully engage the slipper. It's tunable I believe, but I'd have to check with my engine builder. It could be an advantage, but I doubt it.

If most kart clutches don't disengage in the corners, the engine breaking is just so minimal in the small engines it doesn't matter. It could easily be handled with a slip of the clutch, but only needed in really tight corners. Which is the only time I see any of this mattering.
 
I didn't notice any difference in engine braking from my 131 Sudam to my big four stroke. Maybe the big pistons keep the momentum up rather than the compression slowing you down.
 
Kart clutches do disengage more than you think. I lowered the clutch engagement on my 450 one time and when I lifted it did back the kart into the corner. Now I'm not saying you can't learn to drive it like that it is something you have to adjust for. Ive had a couple customers pick their lap times up significantly switching from tranny 250's to kart specific 250's. Some of that I believe is attributed to being more comfortable. Our last 2013 florida all-star series race was won by a shifter 250. So I agree they can get the job done for sure
 
I'd like to try a 450 or 250 without a trans, just to see the difference. But, I won't be gutting mine anytime soon.

With the lower clutch engagement it made it back into the corner? Am I reading that wrong?
 
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