Top Speed

[ObseSSed07]

I see a top speed of about 24mph on open flat road with no wind. I'm 218lbs and I run an 80cc stock setup tied to a Hyper Beach Cruiser. I have ordered a new stage II BBR Spark box, Thrust racing exhaust and a high compression head. I will check my mph after those are installed. By the sounds of the Youtube videos, I may need ear plugs too.

 

[CrazyDan]

I have a friend that's not very mechanically inclined. He bought a zeda motorsports engine that ran ragged as f***, and figured it was a trash motor. He sold it to another friend, and I helped him get the jetting right. That thing screams. The first owner didn't want to listen to me about elevation....moron... His house is at 2600', and the zeda motorsports engines are tuned basically right around sea level. Of course it's not gonna run right.... You can't fix stupid.

 

[JerboaJohn]

yeah jet right means a lot. I can imagine guys in Denver have a heck of a time,,,

 

[dchevygod]

yeah jet right means a lot. I can imagine guys in Denver have a heck of a time,,,

Yep... I'm in Colorado springs area and tuning is hell on fixed jet carbs.

 

[tishla310]

M

Can't believe I haven't seen one of these threads on here yet.... what are you guys getting??

On my old road bike with no shift kit, my tops was about 24mph.

My bike is stock and it cracks about 40 km

 

[Otaku]

All the stockers I have put together for people over the years have made about 35-38kays
Few mods detailed well on this forum, as well as disassembling the engine and cleaning it up.. every bearing pocket seems to be packed with swarf I have found.
as well as machining run-out off the bottom end
replace the Chinese approximation of a carb
and port matching the jug to the bottom end (transfer ports) they have a good 10mm step in some cases.
Skim the head a little..

again all well documented mods..

This made a bike for me that does 68.5 on the flat if I lie on the seat.. it is scary and even steel frames will not survive this long (ask me how I know) interestingly this 68.5 is the same speed that my bike will max out at bombing down a very long, quite steep hill with no engine engaged at all.. again.. scary.

I do not doubt the engine could be improved upon further than this, I do not doubt that more top end speed can be made at the sacrifice of torque and reliability but it really is entering the realms of motorcycle speeds and complexity to do this.. in most cases you can buy a used motorcycle for less that will be much more reliable and in some cases not attract the attention of the law (where applicable)

 

[intrepid]

30-31mph with a heavy steel 30 year old ross bike, stock.

 

[Member 30571]

My 29in Genesis GX 7 did 42mph by gps. I think it could of went faster but I was afraid of s**tting my underwear.

 

[Jug]

My top is 40mph on a 44tooth sprocket, i cruise at 25-34mph usually. Ported cylinder by me, 3rd transfer, boost port, windowed piston, 168 exhaust duration. Its a 1 piece jug so no head mods. I have one of those s**tty cdh66 pipes which i get a little boost from, not much. A 21mm PWK carb, rse reeds. If anyone has any questions about porting or want tips just ask
My wheel size is 26in

 

[hazmat]

Can't believe I haven't seen one of these threads on here yet.... what are you guys getting??

On my old road bike with no shift kit, my tops was about 24mph.

check your jetting and electrical systems to see they are going right and a smaller sprocket should help i use a 44t and get 35mph sometimes 38mph but im still breaking it in