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Post by usmcdoc on Apr 25, 2013 9:27:42 GMT -5
Today I was thinking.No! Actually this time I was. I was pondering why the Aprilla SR50 is such a fast stock scoot. They are basically the same as our Jog/Minarelli engines. Yet oddly we use 15X12 variator weights....and they use 17X12 variator weights. So I marked my variator with a Sharpie pen and did a WOT run with the KOSO 5gram sliders I have been running in it. Been thinking they were too light and was going to go heavier since my BBK should be able to work well with a heavier weight. I had about 6mm of untouched variator surface. All I had for sliders was a pair of generic 16X13 green color 6 gram ones I got off Ebay pretty cheap. So 10-12 swipes down a Mill File and they were now 16X12 and about 5.5 grams. While only 1mm taller than the typical Jog/Minarelli 15X12 sliders...due to their elliptical shape..at the end of travel when sliding them by hand in my variator...they appeared to increase travel by more than just that 1mm. Marked my variator with a Sharpie and installed them. I ran it with the CVT cover off first in case there was a problem and I would end up pushing the scoot home. A few good revs and all that was left of the Sharpie mark.... was a tiny dot! The belt edge was riding almost flush with the edge of the CVT. So then I thought again(2 thoughts in one day..unreal for me huh?) It came to me that when I install Hoca performance variators for folks Jog/Minarelli...they use the 16X13mm weights...1mm taller than our stock 2T weights...so possibly why folks notice a speed improvement? My KOSO variator only uses the 15X12 weights..but has longer channels as it is larger in diameter and has a steeper ramp at the end. Again I mark the CVT..put the cover on and go for a ride. Same Rocket like take off it always had...NO brief acceleration pause it had at 30mph where the rpms drop and the scoot shifts(stock rear sliding sheave) From there it continued to climb to 50 steadily..which is about its top speed. But it hit 50 and was still climbing! My speedo stops at 50..that is as high as it is marked. No clue how fast I was going as I did not think to bring the GPS. But it was a fingers width or so into the white! I could definitely feel more speed as well. Also the road I was on is a 55mph zone and I was catching the truck in front of me. Of course I have no clue if he was going 55....all I know is that I was really moving. So now maybe I understand why the 2T Hoca variator uses 16X13 weights...and the Aprilla use 17X12...vice 15X12 like our standard Jog/Minarelli....CVT. This method WORKS and sure is cheaper than a $50.00-$150.00 performance variator..
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Post by fatboy on Apr 25, 2013 10:56:26 GMT -5
Upon seeing this i ran to my garage and installed the 17x12 rollers that came with my zx pipe that i thoughtwere too big well let me tell you i need to use my gps but i got at least 10mile an hour gain holy schnikees and here i was pissed off at leo vincefor what i thought were the wrong rollers
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Post by fatboy on Apr 25, 2013 11:26:34 GMT -5
Upon seeing this i ran to my garage and installed the 17x12 rollers that came with my zx pipe that i thoughtwere too big well let me tell you i need to use my gps but i got at least 10mile an hour gain holy schnikees and here i was pissed off at leo vincefor what i thought were the wrong it was great while cold i put my gps on it it hit 50after warming up it became sluggish ttake off and i could not get more than 46 out of it why?rollers
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Post by usmcdoc on Apr 25, 2013 11:32:06 GMT -5
Upon seeing this i ran to my garage and installed the 17x12 rollers that came with my zx pipe that i thoughtwere too big well let me tell you i need to use my gps but i got at least 10mile an hour gain holy schnikees and here i was pissed off at leo vincefor what i thought were the wrong rollers The Aprilla SR50 comes with 17X12..and folks wonder why it is possibly THE fastest 50cc production scoot. fatboy..I like this site! I posted the same info on 2 others sites and they negated it. They are stuck in an rut because they think inside the box and use and follow expressions such as.."It's always been that way"...We have always done it that way".. "That is just how it is" and many other paradigms they won't let go of. Being Chippewa we have a proverb...Aytonikii bebalynoc deya so jutokimi esotiiniha... <-- Without risk you shall have no progress... That faster take off and possible 10mph gain you felt may be happening..well..it is!! Go GPS it..sh!t yer pants and giggle. I did..mine was 8-10 mph with the the 16mm tall ones...your 17X12 should better. You don't even have to file them down width wise as I did if folks buy Aprilla SR50 sliders...the work is done..
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Post by 90GTVert on Apr 25, 2013 11:45:28 GMT -5
I've still never tried this, but I would like to note that if you feel like it loses some power on the initial takeoff, it could be that the larger rollers won't let the variator close as far as it can. Easy way to see if that's gonna be an issue is to lay the variator face down on a flat surface and see if the ramp plate sits farther out with the taller rollers. If it does, expect a difference in the initial launch, because the belt won't be able to get as deep in the front pulley for the best gearing.
I've always filed the pulley faces to get full travel, but maybe I'm doing it the hard way? I'll definitely try this at some point. I've always opted out because I'm too heavy to want to lose acceleration.
fatboy, your jetting may be slightly off since it slows down once it's hot. You can unplug the enricher so it stays on and see if the power loss once hot disappears. If so, try going up a jet size and plugging the enricher back in. Another possibility is that the springs in the CVT are heating up and RPM is dropping slightly because of this. CVT cooling vents may help there.
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Post by fatboy on Apr 25, 2013 11:54:59 GMT -5
Could the same thing happen if i have too big of a jet i dont have an enricher it has a manual choke and the belt cover was off during. Testing i also have my slide needle 3/4 up
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Post by usmcdoc on Apr 25, 2013 11:55:16 GMT -5
I've still never tried this, but I would like to note that if you feel like it loses some power on the initial takeoff, it could be that the larger rollers won't let the variator close as far as it can. Easy way to see if that's gonna be an issue is to lay the variator face down on a flat surface and see if the ramp plate sits farther out with the taller rollers. If it does, expect a difference in the initial launch, because the belt won't be able to get as deep in the front pulley for the best gearing. I've always filed the pulley faces to get full travel, but maybe I'm doing it the hard way? I'll definitely try this at some point. I've always opted out because I'm too heavy to want to lose acceleration. fatboy, your jetting may be slightly off since it slows down once it's hot. You can unplug the enricher so it stays on and see if the power loss once hot disappears. If so, try going up a jet size and plugging the enricher back in. Another possibility is that the springs in the CVT are heating up and RPM is dropping slightly because of this. CVT cooling vents may help there. Brent..I checked the height of the pressure plate with stock and modded rollers. Got the same height..oddly. Also I lost no bottom end...I gained a bit. So somehow common assumptions and actual physics don't apply here?...Ya got me bro. All I know is that when folks have questions about mods and cool tricks...I send them your links here..and your youtube links. Brent with all the projects you do..you surely have a set of 16X13 sliders collecting dust that you could sacrifice. Speaking of which..sell me some longacse Minarelli gears will ya? These 13X44 and 13X52 with 12" wheels are too low of a ratio. Like what..13:1? or worse even?.. I want 13X42 or 13X50..hell something..anything has to be better...
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Post by 90GTVert on Apr 25, 2013 12:09:38 GMT -5
Could the same thing happen if i have too big of a jet i dont have an enricher it has a manual choke and the belt cover was off during. Testing i also have my slide needle 3/4 up It could be from richness. A cold engine needs more fuel, so it may be running it's best from the extra fuel when cold, but a little rich once warm.
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Post by usmcdoc on Apr 25, 2013 12:17:11 GMT -5
Could the same thing happen if i have too big of a jet i dont have an enricher it has a manual choke and the belt cover was off during. Testing i also have my slide needle 3/4 up What Brent said. My scoot did the same thing..ran good cold...but lost power once warmed up. The choke was acting as a band aid obviously to an underlying issue. Upped my Pilot Jet from #42 to #45..it got a lil better. Then upped my Main Jet from a #85 to #87.5..problem solved. It was lean..the enricher(auto choke) was merely compensating for lack of fuel.
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Post by 90GTVert on Apr 25, 2013 12:22:08 GMT -5
Brent with all the projects you do..you surely have a set of 16X13 sliders collecting dust that you could sacrifice. I do have some 16x13s, but nothing that doesn't use them or larger already. Don't even have a scooter running ATM. Thought I was working on that today, but can't get to the garage cause granny needs too much help. Speaking of which..sell me some longacse Minarelli gears will ya? These 13X44 and 13X52 with 12" wheels are too low of a ratio. Like what..13:1? or worse even?.. I want 13X42 or 13X50..hell something..anything has to be better... I don't have spare gears for a long case. Well, I may have one set that's 13.55:1. All of my others are 10.13:1 and keep the others here so I can do better wheelies if I feel like it. No way I'm trading another set of 10.13s away. Too hard to find and they're a much better gear for fast cruising. Sorry.
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Post by usmcdoc on Apr 25, 2013 12:36:55 GMT -5
Brent with all the projects you do..you surely have a set of 16X13 sliders collecting dust that you could sacrifice. I do have some 16x13s, but nothing that doesn't use them or larger already. Don't even have a scooter running ATM. Thought I was working on that today, but can't get to the garage cause granny needs too much help. Speaking of which..sell me some longacse Minarelli gears will ya? These 13X44 and 13X52 with 12" wheels are too low of a ratio. Like what..13:1? or worse even?.. I want 13X42 or 13X50..hell something..anything has to be better... I don't have spare gears for a long case. Well, I may have one set that's 13.55:1. All of my others are 10.13:1 and keep the others here so I can do better wheelies if I feel like it. No way I'm trading another set of 10.13s away. Too hard to find and they're a much better gear for fast cruising. Sorry. Brent..aww..come on..one set? That is what I want them for..faster cruising. These stock ones rev so high people look up expecting to see me riding a chainsaw I think.. Also no running scoot ATM?..that sux...so not like you. Wish I was closer I'd come get one up n running for ya...no scoot = not good...
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Post by 90GTVert on Apr 25, 2013 12:52:11 GMT -5
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Post by fatboy on Apr 25, 2013 16:03:50 GMT -5
I took her for a 50 mile ride and lost about 3seconds in low end take off but 10 extra miles an hour is a very small price pay i say it worth it,alsoit no longer sputters at wot on a downward plane not down hill just not a level plane it also does not rev anywhere near as high which. Will save me on gas!! I cant believe what a difference it makes it is truly amazing! !
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Post by usmcdoc on Apr 25, 2013 16:46:28 GMT -5
I took her for a 50 mile ride and lost about 3seconds in low end take off but 10 extra miles an hour is a very small price pay i say it worth it,alsoit no longer sputters at wot on a downward plane not down hill just not a level plane it also does not rev anywhere near as high which. Will save me on gas!! I cant believe what a difference it makes it is truly amazing! ! Good to hear! Not to bad since I went from 15mm tall to 16mm...yours were 17mm tall..so a slight low end barely notable loss is worth the extra 10 mph you now get at lower rpms. Thanks for your input...now maybe we can convince others to try it. many won't because it is not 'store bought' or 'Ebay bought' and labled performance. It is merely a hand made mod....and all too often we get stuck thinking the more you pay...the better it is...and this being free...golly..it surely can't work cause it did not come in a package that said NCY..Naraku or Stage 6 on it...lol.. Hey sad but very true..
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Post by fatboy on Apr 25, 2013 17:01:07 GMT -5
I can' I have bee I have been messing with m with my setup since since I installed 70 cc kit and and could not get any kind of gains from it how fast how fast it got up to speed no not only do I go faster but I still get there faster even with the loss in low end thanx again le Vince was o o was onto something the 4 gram rollers came with my zx pipe i thought they screwed up because the rollers are17 not 15x12
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