Huasheng 142 Crank Shaft Swap

[Stoltzee]

Well the first adapter was a bit wobbly, and I probably hadn't torqued the bolt properly. With the weight of my bike there seems to be some lugging taking place at take offs, so I bet the HF 79cc would be good partner for the stock Q-matic. I have no intention of doing 50 mph hour on a bicycle ever. I can screw myself up just fine on a 10-speed, and I have the knots to prove it.

Straight shaft will work in place of tapered version. The bolt pattern is different where the drive system attaches, however the Q-Matic drive plate can simply be re-drilled to fit.

If you use the 79 CC HF you won't need any speed parts as it has lots of torque to handle taller gearing [11.55 X 1 is standard on the Q-Matic for the HF motors].

Most of our HF test motors easily traveled at 45 MPH or higher. One of our test bikes with the 99 CC version topped out at 54 MPH.

Have fun,

 

[Quenton Guenther]

Hi Stoltzee,

The HF 79 and 99 CC 4 stroke motors provide a lot of torque. If "geared" correctly they are really smooth between 30 and 35 MPH. Your Q-Matic drive simply needs new mounting holes and a new larger primary pulley. We suggest either the 2.5" or better the adjustable drive pulley. Both are available from Grainger or EZM. It is important to drill the new mounting holes in a certain pattern as the drive must miss hitting the valve cover, be low enough to clear the exhaust port, and the idler pivot bolt must be relocated to miss the oil dip stick.

If you need a pattern, just contact us and we can make one for you.

Always remember, you don't have to run at full throttle to cruise at 35 MPH

Have fun,

 

[HeadSmess]

more tools! a smart man! just more tools always means...more shelves!

yep, a diamond bit is about all ive found will get an ezi out out. and yes, they take a long time. use plenty of lube, try and get a coarse grade bit, and come from side on, so it actually cuts. they dont "drill" so well something to be aware of if using a drill press. (make a plasticine "tub" full of lube, hang a weight on the drill arm, and just walk away for a few hours)

other methods are to heat the case around the broken stud, along with some wd40 (panther pi$$!).

hopefully the heat will burn any thread locking goop, and the difference in expansion rates will free up the stud.

and then, theres always a plug cutter... basically a skinny hole saw. drill out the old stud and retap to the next thread size or helicoil it...

tools are great, cus they always get used. just at a certain point, you get so many you forget where they are! at least i know where my magnetic chuck is. and ive never even used it!

 

[Stoltzee]

Hi Stoltzee,

The HF 79 and 99 CC 4 stroke motors provide a lot of torque. If "geared" correctly they are really smooth between 30 and 35 MPH. Your Q-Matic drive simply needs new mounting holes and a new larger primary pulley. We suggest either the 2.5" or better the adjustable drive pulley. Both are available from Grainger or EZM. It is important to drill the new mounting holes in a certain pattern as the drive must miss hitting the valve cover, be low enough to clear the exhaust port, and the idler pivot bolt must be relocated to miss the oil dip stick.

If you need a pattern, just contact us and we can make one for you.

Always remember, you don't have to run at full throttle to cruise at 35 MPH

Have fun,

Hi Quenton, I fixed the old crank, and ready to reassemble everything. I think I'll wait for another build to use an HF Predator. I'm already toying with heavy duty wheels, and a 6 volt hub,which is more readily available along with parts n pieces. Thanks.

 

[Stoltzee]

Rode it today. Seems like those holes made a difference along with cleaning the jet under the idle screw, and I placed a thin peace of photo paper on the fly wheel to gap the magneto. Set the magneto right down on it.

Check it out;https://www.facebook.com/photo.php?v=565198820188750&set=vb.139404869541692&type=2&theater