Huasheng 142 Crank Shaft Swap

Stoltzee

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Aug 31, 2012
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Does anyone know if I can replace a tapered shaft crank shaft with a regular one. Just take out the tapered, and put a straight shaft in.
 
I was told it could be done....I shipped my engine to blowbyyou.com in Bristish Columbia....to have it done by him.....He is a good guy , but the cost of shipping into Canada is prohibitive....You can proably just replace the engine cheaper.
 
You would also need a new motor side cover as the straight shaft motor
uses a different cover.

Your talking about the side with the pull start I gather. The other side I'll be using the Q-Matic from ezm, which I have already.

If I was smart I should just go with a new tapered shaft ($28), (First the bolt breaks, and then the EZ out. Spent $25 on Carbon Drill Bits, $9 on a tungsten Dremel bit (grinding).

Then to be even smarter:
I'll get this engine going again, and then plan on using a 212 Cc OHV Horizontal Shaft Gas Engine - EPA & CARB $119.00 from Harbor freight, and slap a 49cc sticker on it. Then I can go up hills, cruise all day long, it will idle right, take the governor off, and it will probably last me for 5 years with just simple maintenance, and also order a set of heavy duty wheels from "Custom Motored Bicycles" with 11 gauge spokes for $88.00, yes a set.
 
Your talking about the side with the pull start I gather. The other side I'll be using the Q-Matic from ezm, which I have already.
I am talking about the output shaft side motor cover which is totally different on the straight shaft versus the tapered shaft.

Now that I look at it it is the cylinder block and and bearing support that is different
with the straight and tapered shaft.

Never done it so I don't know if the straight shaft crank would work with the tapered
shaft block?

case--38-01.jpg
 
I am talking about the output shaft side motor cover which is totally different on the straight shaft versus the tapered shaft.

Now that I look at it it is the cylinder block and and bearing support that is different
with the straight and tapered shaft.

Never done it so I don't know if the straight shaft crank would work with the tapered
shaft block?

View attachment 49273

Thanks for the advice. I think I read another thread also that said something about them being different, so to play it safe I'll stick with the tapered shaft. Thanks again.
 
are we sure its the case thats different and not just the adaptor plate stuck to the case? cause i cant see any difference between the types, fullstop. it also makes no economic sense to change more than just a crank shaft for a chinese company!

but i have seen three different adaptor plates and a few different engines...none,ie a lone plain straightshaft engine, one to take the chain shs or rhs or something chain reduxes, one for the hoot, and one for the tapered shafts like the qmatics...

unfortunately, theres also several configs of engine depending on use, country and supplier so i cant really say yes or no.

from what ive seen there should be no problem. you may have to check shaft/bearing sizes, as there may be selective assembly making one set incompatible with another set that appears to be identical until micrometers are used! without a stockpile of engines outback to play with, its probably best just to get a new engine. sticking with one type or style of engine ensures a stockpile of parts :)


avoid the temptation to "legalise" an illegal engine. it only makes it worse for yourself when you do get caught. you obviously knew the rules or wouldnt have bothered...
 
Your right about the legalism. I'll just order a replacement shaft (found one already). Then when this engines finished I'll probably switch to a 79cc Predator from HF. The HS 142 has to many issues, but the Predators seem to be more application specific. I can order the engine parts from my state, and affordablegokarts.com has the after market parts for a MB cheap.

Exhaust pipes, performance head
2 Max torque torque clutches
Bored and reworked carb
12 different carb jets
jack shaft parts Pretty Much Everything.

http://www.affordablegokarts.com/mm5/merchant.mvc?Screen=CTGY&Category_Code=MTRBK79
 
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,
 
Wont be needing a new drive shaft. Bought some new tools, and a couple of Dremel bits, and some Cobalt bits. Spent a gang of hours getting through a broken Easy Out, and then re-drilled and tapped the hole. Modified the air filter to increase air flow a bit also. Now I have more tools in place of a new crank shaft.
It was the Diamond Dremel bit in a regular drill that cut through the Easy Out. Next time I have work like this to do I'll have a drill press, or just buy a new engine.:cry:
20130728134927.jpg20130728134953.jpg
 
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