dd50 which bore size?

[GuavaJam]

so i wanna make my derestricted, daily rider dd50 faster all around without killing my gas mileage and not spending too much. which size bore is the best? Or should I just rejet the stock carb? I changed the center spring, weights, already, but still stock with aftermarket muffler. I also don't wanna premix and I'm a light guy. thanks.

[chamisataza]

put 72 cc pollini contessa,v8 exhaust,1500rpm center spring 1000rmp 3xsidespring re-jet the mj to 88 or 90,Kelly racing pully,racing cdi.roller weights 45-48 grms....change the gears to 7.9 gears,(15x42)21mm carb much better.. the more gas the more faster and more spending the faster,...

[GuavaJam]

d*** that sounds like scripts. How much? Top speed? Accel?

[GuavaJam]

I want hard off the line acceleration , top speed 50-60 , and strong roll on midrange.

[GuavaJam]

Thank u all for whatever advice u have

[Wheelman-111]

Greetings:

Your premises must be reconsidered. The performance you describe comes from a fully-modified big-bore setup including aftermarket exhaust, and gear swap. There are too many choices for one reply, but read "An Open Letter..." in Perf Tech. Then remember this: Fast, Cheap, Reliable; Pick any two.

[GuavaJam]

Yah thanks I checked it out. I think I want cheap and reliable so I'll go the stock route. I'll post up specifics of my current set up and see if anyone has advice. Thx again

[Wheelman-111]

Greetings:

In that case, a good variator and rollers well-chosen, a fresh air filter, spark plug, belt, and a clean exhaust should get you to at least 40. Add gears and you'll touch 50, with a negligible penalty on the launch to 5 or 10 MPH.

[GuavaJam]

Yes thanks. I have most of that stuff, and I actually top out at around 48 mph on flats according to speedo, with stock gears. im 135 lbs. Not sure if I have an aftermarket variator, gotta check. What about rejetting the stock carb? What effect wold that have? Also what about a kelly pulley? Thx again

[Wheelman-111]

Greetings:

48 on a stock engine and gears is purty good! Methinks something probably isn't stock, unless the DD is inherently quite a bit quicker than the Elite from which it sprang, or the 60 pounds of weight disadvantage I concede to you matters more than most believe. It took 9:1 gears along with bigger tires and a Polini variator for my stock-engine Elite to hit 49. Weight only affects how quick you get to top speed. Wind resistance, not weight, is the ultimate determinant of top speed for a given power output.

[GuavaJam]

Well this is exactly what I have, and nothing else cuz I bought bike new. 26mm yms exhaust, dio 10% center spring, polini 1000 clutch shoe spring, 7.5 motostar weights. That's it. What would a variator and pulley do? Also carb rejet? Thanks again. Anyone know the forum member who works at a shop and derestricts dd50s? I saw him post somewhere

[Wheelman-111]

Greetings:

A bigger variator can add a few MPH on top if the engine is healthy. It sounds like yours is.

Rejetting the carb on a good-running engine can only make it slower

[GuavaJam]

Another post on this forum about stock derestricted dd50, veedub20 said to rejet carb in conjunction with pulley, variator, and ramp. Thx.

[Wheelman-111]

Greetings:

From your performance numbers I got the impression that the scooter was already "derestricted", which implies that the carb has its jets swapped already. If it hasn't , you shouldn't run it anymore until it is. I don't know what jets or even what carb the DD has, but generally go up a size each for derestriction, pipe, any variator mods.

[GuavaJam]

I see, thanks. Gotta check on that to see if it was done.