my quest for 50mph with DIY and bolt-on mods.

[Jayraye39]

Ok after a 3week span of no starts. I replaced my crank seals and the bike runs nice and agressive. So im back to my original ission which is to hit 50mph with diy mods only.

Im running a triple 40 69cc with 26 x 2.3 wheels. My mod list and top speeds are as follows

homemade expansion chamber, case match, port matched, enlarged exhaust port, enlarged intake port. Transfer ramps on piston crown, timing retard, catnip cdi modified with a polaris stand alone coil. custom 4in by 17mm intake tube, bored out bofeng carb, decked cylinder, decked cnc head 7cc. with thoes mods i was able to hit 43mph. tops.

I eliminated the head because of a stripped spark plug hole. The stock head increased my compression because of it being 5.5 or 6cc.
( dont know what my compression reads) but its more with the stock head. the head was modified for a better squish band ring and matched the dia of chamber to the dia. of the piston. my top speed increased 46mph.

Recently had to change cases for a stripped jug thread. in doing so I stuffed the case using jb weld. this increased my case compression which helps leveling out the force of the cylinder compression. Ran it just now for a top speed run and I hit 48mph.

 

[DAMIEN1307]

Ran it just now for a top speed run and I hit 48mph.

Close it up and call it good before it breaks on ya again...your close enough to your 50...lol.

 

[GW's Motorized]

Close it up and call it good before it breaks on ya again...your close enough to your 50...lol.

You know he ain't gonna settle for 48mph. And after 50mph, he's gonna shoot for 55 lol

 

[GW's Motorized]

I'm thinking shaving a couple unnecessary pounds off your bike might help you out a tad. Could you post a picture so we might be able to see what weight you could drop without harming the aesthetics.

 

[Wrench]

Ya probably only need a 5 mph tail wind to hit 50+mph

Tail winds and a slight grade can make a mph+ difference

That's why coming and going ya need to average the mph

 

[Jayraye39]

well im thinking of just getting the 17mm bing carb. with my port work it can definitely handle more charge. ive read many have had increased performance with a larger carb. just trying to get one under $40 is hard. unless i wait 2months for china to send one

 

[GW's Motorized]

well im thinking of just getting the 17mm bing carb. with my port work it can definitely handle more charge. ive read many have had increased performance with a larger carb. just trying to get one under $40 is hard. unless i wait 2months for china to send one

Maybe you could do a bit of research on boost bottles and see what you can come up with.

 

[EnderbyRider]

I hit 42km today 50 mph must feel fast on a bicycle

 

[GW's Motorized]

I hit 42km today 50 mph must feel fast on a bicycle

40mph is scetchy on a bike, Jay's bike has been raked to get better handling at high speeds.

 

[EnderbyRider]

40mph is scetchy on a bike, Jay's bike has been raked to get better handling at high speeds.

Raked? As in stretched? Longer bike?