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Post by oldchopperguy on Oct 7, 2015 19:14:00 GMT -5
Well, boyz and gurlz,
The old chopper guy discovered yet another "quirk" of our CVT trannies... Lately I've been running a lot of errands on "Minnie Mouse" for meds, etc. down a long stretch of local 8-lane. It happens to have a nice, 4-mile straight stretch, with a stout 2-3% grade, UPHILL south, and DOWNHILL north.
The uphill stretch gives the scoot a good test of its ability to maintain speed on a grade, and the other direction, downhill gives an opportunity to find out the ABSOLUTE top-end with the variator closed up tight. (The speed-limit is 65, and typical traffic-speeds along there run 70-80 in the right "slow" lane and 80- + in the left 3 lanes.)
Uphill, the old mouse will maintain an indicated 72 mph (actual 69). On the return trip, downhill, I hit an indicated  mph (actual  ) which probably approximates what would happen (minus a few mph for windshield-drag, etc.) if I had the IDEAL roller/slider setup and everything was "perfect".
For the record, the shop-manual for the Kymco GV 250 lists absolute top-speed at 70 mph. THAT is for the "Dink" version, and maybe 5 mph slower than a typical American market Grandvista or Bet & Win. Mine had a one-tooth final gear upping years ago, but all else is stock.
Now, the INTERESTING part!
After reaching the bottom, and on the level, the old mouse only slowed to indicated  mph (actual  ). And, she'd stay there even with the throttle backed off a little.
When I came on slower traffic, I had to slow to 65. But... no amount of throttle-manipulating would get back to again. So... The downhill allowed the variator to perform to "perfection" and the engine had the ponies to keep the speed pretty high on the level. I do believe I got just a "taste" of what a perfect combo of weights and such COULD offer.
Definitely worth some experimentation... Playing with weights in my old 150 brought major improvements in acceleration and top-speed, and I think the same might be true with the 250.
Now I know my rollers are the originals, with 8 years and 15K miles on them, they surely are well-worn. I intend to try some 18 or 19-gram Dr. Pulley sliders when time and budget allows. Right now, health issues with the Missus keeps me from having any free time, and paying for meds takes ALL the money and more, but the prospects are intriguing.
As a side-note, I can see the selling-points of the Vespa-jockeys... mph on 12" wheels is NO problem if you're running speed-rated tires, and the wheels/tires are well balanced. Smooth as glass!
Riders who are wondering whether it's worthwhile experimenting with rollers/sliders and weights, rest assured, it is!
Ride safe, work that tranny!
Leo in Texas
PS: It WAS fun to actually keep up with traffic for once... Even though a guy in a lettered-up, numbered Porsche played "thread the needle" around me, and surrounding mph traffic doing at LEAST 80 mph FASTER than us... Doing near the "double-century mark" in a cage must be a trip... LOL! |
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Post by ghcoe on Oct 7, 2015 21:50:53 GMT -5
I just ordered a performance variator with 12g sliders and a set of 11g sliders to play with my scooter a bit. Right now I am hitting 52mph at 7500rpm. I am hoping the larger diameter of the performance variator and sliders give me a bit more with the stock motor. 55-60mph would be cool.
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Post by rockynv on Oct 7, 2015 23:12:31 GMT -5
With my Lance Vintage 150 with the Hoca Variator and larger machined drive face an actual 65 mph on level roads was the norm as the rollers were heavy enough to push the inner sheave all the way out towards the drive face however if too heavy they would do so prematurely and then you won't stay in the optimum torque band so the engine will bog down. Its all a balancing act and compromises.
ChopperGuy going down hill allowed his variator to spin up fast enough to finally close up. There was probably the resistance of a dust line on the boss that he had to scrape past first too. Upping the weight of his rollers by one gram or going with sliders of the same weight as the current rollers will probably get very close if not exactly to the optimum for his needs. Wants well that's another matter but....
On my Aprilia the Sliders are seated in quite nicely now and that 250 has turned into more of a screamer than it was before. Those kids on their small Nija's, Bandits and such probably have put the dartboard with the picture of my bike on it back up in their clubhouses. In the city and on state roads at posted speeds 650 cc and some larger bikes are fair game for the 326 lb Aprilia 250 with the sliders in it.
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Post by spandi on Oct 8, 2015 5:19:53 GMT -5
Well, boyz and gurlz,
The old chopper guy discovered yet another "quirk" of our CVT trannies... Lately I've been running a lot of errands on "Minnie Mouse" for meds, etc. down a long stretch of local 8-lane. It happens to have a nice, 4-mile straight stretch, with a stout 2-3% grade, UPHILL south, and DOWNHILL north.
The uphill stretch gives the scoot a good test of its ability to maintain speed on a grade, and the other direction, downhill gives an opportunity to find out the ABSOLUTE top-end with the variator closed up tight. (The speed-limit is 65, and typical traffic-speeds along there run 70-80 in the right "slow" lane and 80-+ in the left 3 lanes.)
Uphill, the old mouse will maintain an indicated 72 mph (actual 69). On the return trip, downhill, I hit an indicated mph (actual ) which probably approximates what would happen (minus a few mph for windshield-drag, etc.) if I had the IDEAL roller/slider setup and everything was "perfect".
For the record, the shop-manual for the Kymco GV 250 lists absolute top-speed at 70 mph. THAT is for the "Dink" version, and maybe 5 mph slower than a typical American market Grandvista or Bet & Win. Mine had a one-tooth final gear upping years ago, but all else is stock.
Now, the INTERESTING part!
After reaching the bottom, and on the level, the old mouse only slowed to indicated mph (actual ). And, she'd stay there even with the throttle backed off a little.
When I came on slower traffic, I had to slow to 65. But... no amount of throttle-manipulating would get back to again. So... The downhill allowed the variator to perform to "perfection" and the engine had the ponies to keep the speed pretty high on the level. I do believe I got just a "taste" of what a perfect combo of weights and such COULD offer.
Definitely worth some experimentation... Playing with weights in my old 150 brought major improvements in acceleration and top-speed, and I think the same might be true with the 250.
Now I know my rollers are the originals, with 8 years and 15K miles on them, they surely are well-worn. I intend to try some 18 or 19-gram Dr. Pulley sliders when time and budget allows. Right now, health issues with the Missus keeps me from having any free time, and paying for meds takes ALL the money and more, but the prospects are intriguing.
As a side-note, I can see the selling-points of the Vespa-jockeys... mph on 12" wheels is NO problem if you're running speed-rated tires, and the wheels/tires are well balanced. Smooth as glass!
Riders who are wondering whether it's worthwhile experimenting with rollers/sliders and weights, rest assured, it is!
Ride safe, work that tranny!
Leo in Texas
PS: It WAS fun to actually keep up with traffic for once... Even though a guy in a lettered-up, numbered Porsche played "thread the needle" around me, and surrounding mph traffic doing at LEAST 80 mph FASTER than us... Doing near the "double-century mark" in a cage must be a trip... LOL! Leo, I've found that a scoot will hit above-average speeds once the engine has been running WOT after a while. That's how I hit 73 mph on the freeway on a Honda 125 Elite.  |
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Post by dollartwentyfive on Oct 8, 2015 9:05:15 GMT -5
my opinion is that the downhill ride provided the "extra horsepower" that was needed to fully open up the rear pulley.
i wonder if a slightly narrower belt would have the same effect, maybe 1/16 of an inch less.
it's too bad we don't have "adjustable" belts.
BTW, does anyone know if they still sell the 244cc scooter?
is the roketa mc54b a 244cc?
if anyone knows a wholesaler, i have a dealer that will order it for me.
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Post by oldchopperguy on Oct 8, 2015 17:18:03 GMT -5
I just ordered a performance variator with 12g sliders and a set of 11g sliders to play with my scooter a bit. Right now I am hitting 52mph at 7500rpm. I am hoping the larger diameter of the performance variator and sliders give me a bit more with the stock motor. 55-60mph would be cool.
Way to go...
I'm assuming you have a 150 cc scoot. The MOST improvement I ever got with my '07 Xingyue 150 came from adding a Prodigy variator, and playing with roller-weights. Amazingly, I found 11-grams TOO LIGHT, giving me fantastic acceleration and hill-climbing, but cutting my top speed to less than 50 mph at a screaming 9K rpm.
So I tried the 12-gram rollers, and got a top-speed of 65 mph, but at only 7,500 rpm with DOGGY acceleration and NO hill-climbing ability... TOO HEAVY...
I then mixed 3 ea. 11 gram, and 3 ea. 12 gram rollers alternated, and WOW! Good acceleration and climbing, AND a 62 mph top-speed at 8K rpm.
I rode that combination for a season, and believe it's as good as a Chinese 150 is likely to get, especially since I'm no lightweight... I weigh 230, same as the scooter...
If you are fairly light, the 12's may be just right for you.
Other "tweaks" which made a noticeable difference for me included a no-rev-limiter CDI, a Bando coil and iridium plug, along with meticulous adjusting of the "needle" which raises the throttle butterfly, adding a UNI "sock" filter with richer main jet, AND a biggie: replacing the original exhaust header with a full-diameter header.
The factory headers on these usually are SMALLER inside-diameter than the EXHAUST PORT, and restrict scavenging right at the head where it does the most harm. I added a 2-stroke "chamber" exhaust since I had it on-hand (these run GREAT on 4-stroke engines too) but the mufflers are not the real culprit. It's the small headers. Even "chamfering" the stock small header to ease the gasses into the pipe helps.
Now all the engine mods made for smoother running, quick starting, easier tuning and added a little power, BUT it's the VARIATOR and rollers that made the BIG difference.
I really wish I would have tried SLIDERS instead of rollers, but I traded the 150 in on a used 250 before I had a chance to try the sliders. I have heard VERY good things about sliders. They seem to fully open and close the variator much better than rollers, providing better acceleration AND top-speed.
When time and budget allow, I'm definitely switching to sliders in my Kymco 250.
Hope this info may help.
Sincerely,
Leo in Texas
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Post by oldchopperguy on Oct 8, 2015 17:43:49 GMT -5
With my Lance Vintage 150 with the Hoca Variator and larger machined drive face an actual 65 mph on level roads was the norm as the rollers were heavy enough to push the inner sheave all the way out towards the drive face however if too heavy they would do so prematurely and then you won't stay in the optimum torque band so the engine will bog down. Its all a balancing act and compromises. ChopperGuy going down hill allowed his variator to spin up fast enough to finally close up. There was probably the resistance of a dust line on the boss that he had to scrape past first too. Upping the weight of his rollers by one gram or going with sliders of the same weight as the current rollers will probably get very close if not exactly to the optimum for his needs. Wants well that's another matter but.... On my Aprilia the Sliders are seated in quite nicely now and that 250 has turned into more of a screamer than it was before. Those kids on their small Nija's, Bandits and such probably have put the dartboard with the picture of my bike on it back up in their clubhouses. In the city and on state roads at posted speeds 650 cc and some larger bikes are fair game for the 326 lb Aprilia 250 with the sliders in it.
Rockynv,
Yeah, I think you hit it on the head. And, the original rollers must be near "toast". I'm surprised she runs as well as she does... I've GOT to get some sliders in "Minnie Mouse" for next season!
And indeed, those spaghetti-burners are snake-strike-fast per cc! The Italians DO know how to make 'em go! Back "in the day" my pal Ed bought a Ducati 250 motorcycle... Single-cylinder, plain-Jane and classic Italian. It would keep up well with the then-current 500-650 cc bikes too!
He liked it so well, he saved up his pennies and bought the first model Ducati Darmah. I believe it was 750 or 800 cc. With that "desmodromic" head, and no valve-springs, it was an ANIMAL!
It had TORQUE like a Harley, and revs like a Japanese 750... (I've felt a similar sensation with today's POLARIS VICTORY V-twins). It would turn 0-60 in 3 seconds flat, and top out around 165 mph. That's not so SLOW even by today's standards!
As for my "wants and needs" for the old mouse, well, she does OK for most riding. She's got very good acceleration, and tops out just over 80 mph on the flat. But cruising up and down hill, with headwinds, she realistically is limited to about 65-70 tops.
Scooter riders often equate TOP-SPEED under ideal conditions, with REALISTIC CRUISING SPEED with hills and wind involved... LOL! They are two vastly different criteria. Just because a 150 might GO 60+ mph doesn't mean it will CRUISE even 60... Same with my old tea-kettle.
What I'd like, in a perfect world, is for the old mouse to top out near , and cruise near 80. That is probably a tad optimistic, but something to shoot for. In the real world, even the new Kymco 4-valve, fuel-injected 300's are not quite THAT frisky... They'll often top , but as for CRUISING, probably 75 is realistic... But, a few more useable mph would be welcome. And I know they're hiding in that old girl somewhere! I think they're sleeping in the variator... LOL!
Health issues and budget keep me from doing much right now, but I hope to get sliders over the winter and try them out next season. I may put Minnie on a spaghetti diet...
Ride safe, and keep ticking off those 650 boyz!
Leo
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Post by ghcoe on Oct 8, 2015 17:45:32 GMT -5
Yes 150cc. Scooter gross weight 243, my weight 135. Already got the performance CDI and coil. Need the plug still. Next steps are exhaust then carb manifold and then I will play with some port and polishing.
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Post by oldchopperguy on Oct 8, 2015 17:58:14 GMT -5
Yes 150cc. Scooter gross weight 243, my weight 135. Already got the performance CDI and coil. Need the plug still. Next steps are exhaust then carb manifold and then I will play with some port and polishing.
Sounds like maybe the 12-gram weights might be perfect!
The exhaust can bring a good improvement over stock, but I'm not sure I'd go to the trouble of head-work. These engines, bone-stock put out over 10 hp, and have good torque too. That is a full 1-hp per cubic inch. Not bad for a daily driver. I'm not sure porting/polishing and carb work will bring enough improvement to warrant the labor, but that's just me... It will certainly help some.
I went to a dated old 250 simply to get a cruising speed over 60 mph. Most any old 250 will run that fast, and allow at least limited freeway use. Trouble is, traffic around here is getting faster and FASTER! Now, it's not really "safe" on the freeway below 75 mph MINIMUM.
Oh, well, you can always use a little "extra"... LOL!
Do keep us posted, and ride safe!
Leo
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Post by ghcoe on Oct 8, 2015 18:05:58 GMT -5
Yes, doing it more for fun and experience than out of necessity. Thanks for taking the time to tell me your experience.
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Post by nulldevice on Oct 8, 2015 19:09:01 GMT -5
Leo: What I'd like, in a perfect world, is for the old mouse to top out near , and cruise near 80. That is probably a tad optimistic, but something to shoot for. In the real world, even the new Kymco 4-valve, fuel-injected 300's are not quite THAT frisky... They'll often top , but as for CRUISING, probably 75 is realistic... But, a few more useable mph would be welcome. And I know they're hiding in that old girl somewhere! I think they're sleeping in the variator... LOL! Read more: itistheride.boards.net/thread/8763/another-factoid-concerning-cvt-habits#ixzz3o1Ya5GOlHey! What you would like from your 250cc scooter sounds like about the performance level I had from my 1968 six speed Suzuki 305 Raider. Those smaller two stroke twins would really run. It also sounds only a little bit slower than my current ride, a 2012 Majesty 400. Good luck in your power search. |
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Post by rockynv on Oct 8, 2015 20:15:12 GMT -5
If the chance presents itself I would love to take an Aprilia 250cc Chesterfield out for a spin with the Ninja Boys. I kind of wonder how they would react to that 150 mph 250cc bike?
Here is a mild street version hitting almost 145 mph:
Here is a track version:
R6 VS the little Aprilia 250:
Just wimpy little 250cc bikes.
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Post by oldchopperguy on Oct 8, 2015 23:20:37 GMT -5
Rockynv,
Woo-HOO!
Those Aprilia 250's are SOMETHING! Back in the fifties, the Italian-made Harley Davidson "Sprint" 250 single made a whopping 15 hp... And it won its share of races! How the ponies have increased!
Nulldevice,
Your Suzuki reminds me of my first non-Harley ride... Back in the sixties, I salvaged a Suzuki 250 6-speed "Hustler". It had been run over by a truck in a pal's parking lot. I spent a summer and a couple hundred bucks fixing, and making sort of a "café racer" style ride. That thing would SCREAM! A local 2-stroke guru tweaked it for me, with chamber pipes, carb/intake work and such. It would do 0-60 in 4 seconds, and top out at over 130!
It could eat Brit 650-750's for lunch! But alas, NO torque... To get it to go like that, you had to keep it "on the pipe" and use all those gears... But once mastered, it was mighty fast!
Then, there were those incredible Kawasaki triples! The 500 and 750 rides were nicknamed "Widowmakers" due to their SCARY-FAST acceleration, top-speed... and frame, suspension and brakes barely adequate for a 150 grocery-getter... LOL!
There IS something enjoyable about getting a small engine to perform like a big one, and the Italians do it better than most!
Now I'm "waxing nostalgic"... Memories of those beasties makes my docile Kymco seem mighty tame!
Enjoy those ponies!
Leo
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Post by rockynv on Oct 9, 2015 6:50:16 GMT -5
Leo, Suzuki worked out a deal with Aprilia to be allowed to cast their 250 cc blocks for them if Aprilia would reciprocate by helping them tweak their own designs. It worked out quite well for Aprilia since they got access to a decent foundry at pretty fair pricing. They pushed those 250's to some amazing levels of performance and they did sound sweet while doing it. Imagine what your Hustler would have done with one of these Sub lb Race Jockey's riding it instead of one if us 250+ lb Gorillas. Not enough consistent torque through the throttle range to work well in a CVT scooter but the thought of pulling off an Aprilia 250cc Chesterfield transplant into a scooter with 15 or 16 inch wheels does have a certain appeal with the potential to double the effective top speed. Even if not doubled that Aprilia sound would probably be worth it. Music to this old Sicilians ears. Currently I am still getting used to the sliders in my Sport City as the extra pull especially when laying on the throttle between 5 and 50 mph still takes me by surprise since I am still not expecting it to pull like it does. Variator is getting the embedded lube from the sliders rubbed into the ramp plate and they are just moving more fluidly together the more I ride it. Yes I have been a bit timid since my off this past spring and have been a bit fearful of laying into the throttle and having the extra pull putting me into a slide which is combined with getting use to the sparser tread pattern on the Micheline Power Pure up front making one believe it could not possibly hold a corner as well as the seemingly more aggressive tire that came stock on the bike. |
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Post by oldchopperguy on Oct 9, 2015 23:57:14 GMT -5
Rockynv,Have a bone, friend!Sounds like Aprilia and Suzuki both benefited by that deal! Italian giddy-up combined with Japanese metallurgy is a match made in Heaven! Yeah, my old Hustler would have gone ballistic with a pound Asian road-racer! I weighed over 350 (OK, I weighed 375...) pounds back then! Weight makes a LOT of difference... My chopper, "Old Blue" would turn mid-elevens in the quarter-mile with me on board, but... With my 4' 6" 76-pound gal-friend at the controls, Old Blue would run in the mid-tens! She was an ANIMAL! Albeit a really adorable SMALL animal... LOL!
Hmmm... An Aprilia 250 in a SCOOTER would be slick! There have always been clutch 'n gears setups in scooters. And the final drive sprockets could be tweaked to work with whatever size wheels needed. Heck, it's not uncommon to find Harley V-twins in old Cushman Eagles, and 4-cylinder Japanese cycle mills in Ruckus-style scoots! You really peak my interest with your conversion to sliders! Sounds like you are getting the results I'd like! Gotta do that for next season! I have a Michelin Power Pure tire (with my infamous painted whitewalls) on the rear of old "Minnie Mouse" and have been very happy with it. True, it doesn't have all that much tread, but it seems to be a fairly soft compound, and holds onto the road well, even when wet, or sandy. My front tire is a Shinko SR 723 whitewall, and its handling is fantastic. It's the cosmetic opposite of the Michelin, having a traditional old-school "Vespa" street-tread. Both tires have superb handling up to the top-speed of the old mouse. Of course, it might be different if the old tea-kettle had the power to spin the rear wheel with aggressive throttle handling. Both tires DO behave beautifully in a high-speed panic stop, sliding straight and controllable.
I really TRY not to get into a turn fast enough to "push the envelope" with the front tire... HeHeHe... Getting too old!
I hope you do one day build that Aprilia 250 scoot! It would be a real "barn-burner"!Ride safe! Leo
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+ in the left 3 lanes.)
mph (actual 
) which probably approximates what would happen (minus a few mph for windshield-drag, etc.) if I had the IDEAL roller/slider setup and everything was "perfect".
mph (actual 
). And, she'd stay there even with the throttle backed off a little.
