Pocketbike Forum banner

Status
Not open for further replies.
1 - 9 of 9 Posts

·
Banned
Joined
·
21,721 Posts
hey, does anyone know what kind of big bore kit i need for uberscoot, no one can tell me and they said to try this site out, i was told i was a huasheng 49cc here's pictures of engine and its a 2 stroke. thanks alot
Hello and welcome to the site...The engine you posted doesnt have a bigbore kit you can buy anymore as per say since PBU went under but with a dremel and some other modifications you can turn a bone stock engine from 1.6/2hp into anywhere from 2.25-9hp...........

Another fact about the engine you posted is it is a Chinese ripoff of a real Mitsubishi brand engine....








Good luck
 

·
Registered
Joined
·
82 Posts
Discussion Starter #3
thanks cam2, by far the most information on this engine, hours searching and emailing, nothing. u know where i can find info on fixing up my engine like; what to google or something
 

·
Banned
Joined
·
21,721 Posts
thanks cam2, by far the most information on this engine, hours searching and emailing, nothing. u know where i can find info on fixing up my engine like; what to google or something

Theres plenty of threads Ive participated in and its best to know upfront that the engine is a tool based engine used for trashpumps , augers and brushcutters.................

What sux is that photobomb is holding my pics at ransom and have screwed-up the pics in those threads/posts.....lol



Your best bet is to buy a brand new topend kit , modify the topend kit by softening the sharp edges on the pistonskirts only with 4000 grit sandpaper and indexing the sparkplug then widening/polishing the transferports and intake also exhaust ports then chamferring all to reduce ring grab and premature piston failure then totally disassemble the old engine, split the crankcase and blueprint the bottomend to the cylinder, reassemble the engine without a basegasket under the cylinder[just use fuel resstant RTV or Hondabond,Yamabond]modify the intake to flow more fuel volumealso with a boost bottle nipple for a boost bottle,modify the 15mm carb to a 17mm carb and getting a velocity stack with built-in choke and hp airfilter, reducing the drag on the flywheel by clipping the fins 3/8" and adding a rocket key lightening the clutch so it grabs at a higher rpm and gutting the e-starter of brushes and magnets so it doesnt rob hp......
 

Attachments

·
Registered
Joined
·
24,101 Posts
That's right, there is so much you can do. If you can cut down a stock cyld, and put an alum alloy or billet head on it so you can make more compression.
 

Attachments

·
Registered
Joined
·
82 Posts
Discussion Starter #6
k i can cut down the stock cylinder, and get alluminum alloy head for my engine? when u say cut down my cylinder, what does that mean?
 

·
Super Moderator
Joined
·
2,146 Posts
i whould start small you know do a base gasket delet rocket key mod the muff box and add a boost bottle

then if you still want more power port and blue print it do a turbo crank mod lighten the wrist pin and flywheel

then once you do all that then do a head chop

If you only do a head chop I don't think it's going to run so good without building in velocity
 

·
Registered
Joined
·
82 Posts
Discussion Starter #8
i trying to find tutorial on base gasket delete u guys know where i can find 1?
thanks for all the help btw
 

·
Registered
Joined
·
24,101 Posts
there is no book on how to turn a backpack engine into a hot rod engine, there are basics. you don't have to remove the cyld to remove the base gasket. Put the piston on TDC, remove the 4 cyld mount bolts. staying on TDC pull the cyld up till the bottom of the piston is a BDC keeping the rings in the cyld. Scrape off the paper base gasket, I push a paper towel in the case hole so nothing can fall in. clean both mating surfaces. Get your Yamabond put a tiny bead on the case side, and I spread it real thin with my fore finger. drop the clyd down lighty, put the cyld bolts, only finger tight, wait tell the next day and tighten them, that's it. You will feel the difference when you pull the rope. the cases have to be air tight so gaskets and crank seals are important, no leaks. don't think there is more than 20 or 30 pound of pressure down there.
 
1 - 9 of 9 Posts
Status
Not open for further replies.
Top