whats the best 2 stroke set up

[doneabee]

:scoot: I work in in a bike shop and i have lots of parts at hand and i built a sick 50 basic stock case head cylinder and piston just put my mind and the othere techs minds in one bike and whala! Got 70mph outof a 06 xspeed 2 stroke 50 , all i put on was a pipe ,carbon reeds and 3 days of off the clock work! I want to know what some otheres have done so i can try yours out to i hae 4 of the same engine so i want to find the sickest out there and put it on a bike.

[90GTVert]

I'd love to know exactly what you did to go 70MPH on a 50 with just a pipe and reeds. If that was the stock speedometer, your speed could be much lower. Please don't take this as me being a jerk, but you just never know, were you on flat ground or downhill? The gearing on most scoots would mean you'd have to be turning probably 12-14,000RPM to hit that speed I'd think.

The 90ccs are the way to go if you're willing to machine the cases and put some time in. If you just want a fast scooter as a toy and not a rider, you might wanna look into some high end race 70cc stuff and spend some money. With enough money and work they can do more than your current top speed in the 1/8 mile.

Here's a member's 103cc build...
49ccscoot.proboards.com/index.cgi?board=builds&action=display&thread=633&page=1

[Fox]

Yeah I was just thinking your speedo must be off because a 50cc won't do 70 unless it's a streamliner and even then you'd have to change the gear ratio in the rear end and add a port job, big carb, tune it for days and be under 100 lbs. etc... but 90GTVert beat me to it. I think you are either mistaken or you're an internet fraud that likes to screw with people. Hell, a 250cc 4 stroke will only do about 75-85 tops so I really doubt your really getting 70mph from a stock 50cc.

[doneabee]

OK it is a stock speedo but there were a few things i did leave out, it also has new rings and piston but they are stock 40mm, and also had allot of port work but there still the same size just a few tricks. This thing comes to life but u have to get into the power band first if not ur dead in the water. I need to work on that. But as for it not doing 70 it mite not but I'm real close. I also work on these all day every day at 2 differt shops where i live so if u think I'm a fraud that's Ur prob u need to remember anything is possible once. Ive got to go to work now as we speak so ill check this when i get home. oh yea I'm looking for fast and dependable.

[90GTVert]

Fast and dependable = 90cc+. My 99cc would go 60MPH under 10,000RPM. I cruised it at 50-55MPH all day. I got about 7,000 miles on it before the stock crank finally gave up, but with a good crank it could go even longer. The 90ccs can make you a nice wide powerband as well. None of this on/off that it would have to be to get any real power out of a little 50. You can still make a 90cc peaky, but that's not what you would want for a reliable street scoot.

Care to give us any insight on your tricks? Port timing? Port duration? Ignition advance/retard? Needs race fuel? Etc...

[doneabee]

Basically it is the same time, duration and ignition just cleaned up. you dont want to change any of that just make it atomize and breathe better. What i did is smoothed the exhaust and the intake side but on the intake side i went back and made it look like a golf ball inside. That way it will atomize better. The better the fuel is broken down the more hp u make. (as u prob know but for everyone else) Anyway most of the time i dont change the sizes of the ports because im nowhere as smart as the man that designed the engine so ill let them decide that. Also i changed the squeeze gap with the base gasket.
:thumb: give more as the post come, im dealin with a brain fart rite now

[90GTVert]

Well, you actaully did change your port timing and duration. I guess you just didn't know you did. Removing the base gasket would lower your port durations a little, which usually makes the engine want to rev a little less... kinda the opposite of what a small bore would want I'd think.

Got any pics of the porting? I know about leaving a rougher surface in the intake tract to create turbulence instead of a laminar boundary layer, but I've never actually seen someone dimple engine components like a golf ball. It's usually something like roughing up a surface with 100ish grit sandpaper to get that effect. The path from teh carb to reeds is so short that it's hard to imagine a huge effect there. Did you dimple the inside of the boost and transfers and crankcase or something? After all, the intake tract of a 2 stroke reed inducted engine goes from teh carb to the intake through the reeds into the crankcase and up into boost and transfer ports. It's not just a simple carb > intake > port deal like a typical four stroke.

I hate to be a doubter, but 70MPH is quite a feat with a nearly stock 50cc. I will grant you, I really never messed with tuning 50s, I'm fat so I move up to 70cc or better. lol

[doneabee]

dimple the inside of the boost and transfers and crankcase or something? After all, the intake tract of a 2 stroke reed inducted engine goes from teh carb to the intake through the reeds into the crankcase and up into [boost and transfer ports], you got it takes alot of work tho i smoothed them and took a glass bead blaster to make the dimples sorry it dont look like a golf ball its the same idea tho but u know what im getting at im gonna do another and ill take pics of it, ill also map the cylinder im glad i got the opportunity to talk with you ill learn from u as well as i hope you learn from me. Its all about trying something new. Its easy to bolt on a bbk and get hp. I want to try to get as much out of what i have and then transfer what i find in to a bbk. follow me

[90GTVert]

I get what you're saying. Good to mess witht eh cylinder that you'll be putting aside rather than the big bore kit.

That's a neat idea with a bead blaster. Never messed with one so I don't really know what finishes you can achieve, but I get the idea. You've certainly spiked my interest. Some of the other folks here are smarter than me on this stuff, hopefully they'll chime in for you. If you haven't already, check that thread out that I linked you to earlier. 190mech made some very nice mods to his cases etc... He builds his own custom pipes as well.

[motomech]

Just to give an idea of what it takes to get really to 70 m.p.h. on a 50, I will relate my experiences racing Mini's in Calif.
Started w/ a liquid-cooled Honda NS50, 6 speed motorcycle. Then bored it to 58cc using a KX 60 piston, ported cyl. and modified head, CR 80 ign., trans(close ratio), reed block and manifold, 28m/m flat side carb and special hydro-formed pipe.
Turning over 15,000 r.p.m.(est. 15 h.p.), I was clocked w/radar @ 71 m.p.h. up the long straight @ the "Streets" track @ Willow springs.
So yeah, I'm always leery when people throw that 70 m.p.h. number w/ no proof.
Easy to say, hard to do.

[stepthrutuner]

I'm with you motomech. From my observations it takes 12+ rwhp to go that fast on a small bike/scooter. For a 50 2t to make that kind or power it would have to spin close to 15,000 rpm. No doubt about it. The power would be like a switch and would be anemic below 9,000 rpm. Exh prt. duration would be 200+ deg. to get revs like that.

[2strokd]

I too agree with the others . Just too hard to believe w/out vids or at least pics . I (we) wanna believe, trust me! But its 70MPH and i have seen some screwy stock speedo,s :no: :rofl: :help:

I have always wanted to use these guys :devil:
:needpics:

[doneabee]

no prob ill have both very soon ive been in the middle of moving in a house with a shop, so i havent been on here bbbbbbuuuuttttttt, this is the only prob i have with anyone on this thred soo far i asked for ur setups nota a critisizem or nobelife of what i have and i have not one yet, just I DONT SEE HOW U GOT 70 out of a 50 2t, i said its a stock speedo already! IT CAN BE WRONG. anyway now that that that is out if u have something besides "i dont belive" put it out there otherewize stop wastin mine and ur time

[90GTVert]

I told ya what I think for fast and dependable. Check out the ongoing Venus build thread for details on my latest 90+cc. It's slow by your terms at only 58MPH max so far (more to come I hope) and I don't even have to tuck to do that speed, but it'll do 50 in 1/8 mile and I'm roughly 300lbs. I really don't think you're going to beat that sort of performance with something that can be reliable short of going to a big bore stroker. You can beat that performance pretty easy with some of the race 70cc stuff.... but that stuff is also more expensive and I'd be quite surprised to see a super high revving engine last for thousands of miles and have good street manners.

[doneabee]

thanks u have been helpful it just gets frustrating dealing with the obivious i like the hole bare bones bike i have one in the works as we speak i have a 06 eton beamer 2 striped and a freind fo mine just got airlifted off his 150 red cat last friday so he had to get rid of it (wife made him) hes ok tho anyway its going on the 2t 2maro it lined up well had t cut and weld just a bit not much tho got to finish the wiring ill post pics i have 6 scoots the reason i went for this wasent for me but for my customers and i have a few engines so i was gonna give thm a try then pass it on but as for my own bikes i have a 01 zuma,01 cpi gtr ,beamer 2,xspeed,and a 10 ruck china clone its new prob sell it,and last but not least a 09 t3 retro china 4t oh yea 7 a 07 smashed 150 redcat to lol! the beamer swap bike is gonna be my new truck i gota trailer build for it ive got the bike trailer just have to strip and wire the lights on it and floor it like i say got lots of pics ccomin just have to figure how to get them on here vert if u will msg me and let meknow how to get my bikes on the botom and pics on here thanks