My Harbor Freight 2.5 project

GoldenMotor.com

Mike B

New Member
Mar 23, 2011
2,256
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Central CA
I have a Mosquito Stinger stand up scooter. The King of stand up scooters, I loved to smoke all the teenagers with it. Sixteen inch bicycle wheels, drum brake in back, V brake in front. All aluminum. Has a 40 cc 2 HP 2 stroke motor with integral 6:1 gearbox.



But the motor has this high speed drop out problem and I don't want to tinker with it anymore. Not to mention, it is loud and obnoxious. So, remove the existing stuff and build a motor mounting plate with a jackshaft underneath and redo the whole back end.

It was either that or build a bike and I already have another bike project lined up.
 

chainmaker

Well-Known Member
Jan 19, 2010
2,634
69
48
Ma USA
That thing is pretty cool. Im working a HF project too, they are popular this year. Cant wait to see how fast your scooter goes with the HF.
 

Mike B

New Member
Mar 23, 2011
2,256
7
0
Central CA
Thanks.

Yeah, it's a thrill. The thing that makes it so is that in normal operation, ie going down the road and looking down the road, you cannot see the vehicle. It's like a magic carpet ride. I added the louder than you like expansion pipe and a bigger wheel sprocket with a freewheel, so it pulled real good. I go 215#, so I didn't want to burn the clutch.

I don't want speed, 25 is plenty fast enough. I want torque to pull my lard ass off the line.
 

Mike B

New Member
Mar 23, 2011
2,256
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Central CA
Got the motor off and all looks good. Looks like I can stick the jackshaft in the box. That box is strong, 3/16" aluminum, with about 1/2" thick where the motor was mounted. I will use these holes to put in a quarter inch aluminum plate to hold 1 standard 5/8 x 1 3/8 bearing and the other one I'll just cut a 1 3/8 hole in the side of the box.

That will keep the jackshaft under and independent of the motor mounting plate. Looks like there is easily enough room for the HF 2.5. There is 14" from the front of the box to the end of the "fender"
 

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Mike B

New Member
Mar 23, 2011
2,256
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Central CA
Yeah, this'll work. Even looks good. I feel like Tim Taylor...more power!

Clutch and jackshaft stuff on the way, still have to get some aluminum for mounts.

Good looking engine.
 

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Mike B

New Member
Mar 23, 2011
2,256
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Central CA
That's nice.

Nah, I think it could have done 35 with the stock small sprocket, but that would be too fast for me. With the 40 tooth on the back the ratio was about 22 and 25-30 was the limit. The torque was good though. I could just crank and it would take off good even up hill with 220 lbs of me on it.

Did you ever fry your leg on that pipe?
 

scotto-

Custom 4-Stroke Bike Builder
Jun 3, 2010
6,505
24
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Ridin' inSane Diego, CA.
That's good torque and plenty fast....much more practical than my screamer there lol. That pipe is all top end but it does come on pretty fast and will turn 18,000 rpm.

And yes, i've burned my leg pretty good on this pipe, but way worse on some of my others and man does that smart!!! I've started wrapping some of them but hate to cover up the chrome on this one so I'm extra careful.

dnut

That's nice.

Nah, I think it could have done 35 with the stock small sprocket, but that would be too fast for me. With the 40 tooth on the back the ratio was about 22 and 25-30 was the limit. The torque was good though. I could just crank and it would take off good even up hill with 220 lbs of me on it.

Did you ever fry your leg on that pipe?