Whats the best performance upgrade??

philmuck · #1 (**permalink**) 10-06-2008, 04:42 PM

What is the best performance upgrade for the 70-80cc chinese engine???

Clotho · #2 (**permalink**) 10-06-2008, 05:09 PM

A tuned expansion chamber.

filestyle1 · #3 (**permalink**) 10-06-2008, 06:50 PM

I second that

Motoschwinn · #4 (**permalink**) 10-06-2008, 07:05 PM

Well maybe not the BEST.... But a good NGK spark plug, accel wire and boot makes a huge difference too. My bike starts SO much quicker now....

**Bikeguy Joe** · #5 (**permalink**) 10-06-2008, 07:10 PM

Bicycle Motor Preperation And Care

apple101 · #6 (**permalink**) 10-06-2008, 09:43 PM

Quote:

Originally Posted by filestyle1

I second that

Me too! I am making a guide on it now. Check it out here:

Fatty Tuned Pipe

goat herder · #7 (**permalink**) 10-06-2008, 11:49 PM

what joe said.....I recently ported everything that can be ported, the china and it is twice as strong since I brock it in 3000 miles ago

goat herder · #8 (**permalink**) 10-06-2008, 11:52 PM

stock pipe , but I did drill holes inside of it. breaths better you do want a little back pressure

Andyinchville1 · #9 (**permalink**) 10-07-2008, 12:42 AM

Hi,

While technically not an engine mod, dollar for dollar, the most speed increase you will get, is by going with a smaller rear sprocket.

The best engine mod is probably the tuned pipe...

Hope this helps.

Andrew

goat herder · #10 (**permalink**) 10-07-2008, 01:02 AM

yes true but It cost about 10 dollers for a rotery file if you have a drill already. I truely wish I had done this a long time ago. Last after motor break in I used one of kings sales and serv sprocket a 40. The gasket under the jug blocks about half the air flow to the intake under the jug.the piston skirt blocks half the air flow at the intake by where the carb mounts These are now huge!!!!!! biggies to me now!!!!!! by the way I loved your sprocket