belt size chart

[REDKYMCO]

Streido is that one of them basic 12v ones you could get from argos for use on wheel nuts for about twenty pounds i think they were branded RAC, do you also use use the impact wrench to tighten the nut is there not the risk risk of over tightning the nut using a impact wrech as im sure i read its only about 40ftlb torque although i could be wrong or is that only a worry if using a expensive/powerfull impact wrench, i have a torque wrench bar but obviusly its stopping the variator from turning without using some dodgy idea from you tube of jamming it with a block of wood or the even worse method i seen of removing the spark plug and inserting a long metal bar through the hole and jamming it against the top of the piston so it could not move up the cylinder ...
Good idea about the lock thread as long as you can remove the nut again at a later date I now know what to ask the wife to get me for christmas a cordless impact wrench...
Sorry about all the questions i know i can go on a bit but as times are now harder i need to learn to maintain my scoots myself as i need them to last......

[streido]

Yeah Kisbee i got that exact RAC one that Argos sold. They stopped selling them now tho, at least in Scotland, so i had to get mine from ebay off a guy in England for about the same price.

Ive taken my variator nut off and on at least 15-20 times using it and had my clutch off 5-10 times too. I usually give it 5-7 impacts aft i gwt it hand tight 1st. Been fine for me, ive had no issues or problems yet. The RAC one comes with a socket that fits the variator but not the clutch. I just use a standard socket from my socket set on the impact wrench for the clutch side, been fine with that. Think its a 14mm if i remember for the clutch side.

I def got my moneys worth from it over the last 6months, changing belts, rollers, variator, clutch, and just for taking it all apart to clean iy out now and again.

I tried the spanner on the variator trick off youtube but couldnt do it and i didnt fancy putting it back on with that method. Threadlock wont stop you getting it off again, just stops it working loose, a bit like a nyloc nut does. Just put a small drop on the threads, not too much or it will get into outer variator and its harder to get that off. Saying that i always end up with a little on the outer variator behind the.nut. No prob tho, just waggle the variator side to side while pulling and it comes off, i paniced at 1st time i tried, thought it would never come.off after i removed the nut!

Do it yourself and you will save a fortune over the years and you get to feel like a real mechanic   . I knew nothing about scooters till i got my Kymco, now i always have a go to fix it and only go to a mechanic if i cant fix it myself.

Check the rollers, variator faces, clutch, belt and give it all a good clean out with a paintbrush and maybe some electrical spray cleaner if its oretty grubby.

Good luck. Get that xmas list to the wife asap

[streido]

By the way, it wont work off you scoots battery, you need a car battery or cig lighter frm a car. Or i just use my old car charger and hook the leads from the socket wrench to the charger leads, that easier if you got a charger already?.

Sorry for typo's. Either my fingers are getting bigger or my phones keyboard is getting smaller 

[Mrperfektone]

I've only driven 1000 km on kevlar belt so I do not know how well it keeps. but I've heard very good things about kevlar. scooter will be geared differently when Malossi belt is wider compared to the original, which means it will be a little more high geared.

Regards Rene

[streido]

I've only driven 1000 km on kevlar belt so I do not know how well it keeps. but I've heard very good things about kevlar. scooter will be geared differently when Malossi belt is wider compared to the original, which means it will be a little more high geared.

Regards Rene

Hmmmm, Rene, there seems to be 2 camps on kevlar belts, those who love them and those who dont. I never tried one yet so i have no idea. If the belt i get from work is no use then i plan on getting a Malossi Kevlar to try it. The one im looking at wont be wider than my stock belt as i am going for a non stock size. They have one slighty longer but its only 17mm wide so my gearing at the rear will be the same as my stock belt is only 16-17mm wide now and thats ok for me.

[sidthesloth]

Try using a clutch holder and spanner, no unnessecary shock to your crank bearings.

[REDKYMCO]

Does the clutch holder also fit the variator is it a special tool for the kymco engine or universal, im suprised with the 139qmb engine being so popular that some kind of holding tool is not readily available on ebay etc. i would imagine the first time you remove the variator nut it is probably the hardest as its probably very tight from manufacture unless you have a decent impact wrench.....

[streido]

You can buy a variator removal tool i think from scooter assassins or im sure i saw them on ebay before?? They're about £10-12 when i saw them im sure.

[sidthesloth]

Yeah, a universal clutch holder, can get them from your local bike shop.

[woodcutter]

yesterday tryed 1000 rpm torque spring with new 729 bando on 5.7g rollers and was much better.

I've had this annoying mid range accel. flat spot on new 729x18 and stock spring and 5.7g.
start was ok but than revs got realy high without any noticable progress. I needed to twist off and on the throttle a couple of times followed by drop in of rpm's, poor acceleration and some rattle-like noise coming from rollers or movable face guides?
Also I got some light rubber grinding vibrations at top speed. anyone have idea what it could be?
1000 rpm contra spring solved this but I want to do some more learning and trial-error do-it-yourself jobs 

for me, oem 729 is short, leaving about 5mm of marker at the edge on the front pulley and is 3-4mm in the rear clutch pulleys.
It's ok for oem variator but limiting top speed.

So, I installed 740x18 and flat spot was even worst than on 729 +during deceleration it was sticking in rear pulleys.  . Installed 1500 rpm spring, 6g rollers but fly springs left stock as I like the way where it engages.
Got much better result and top speed and as I can see longer belts needs a little bit heavier rolles and stiffer torque spring but keeps take off ok cos it's sitting at the top of the driven pulleys.

agility have enough power and it's cool how much could be gained by properly tuned variator.

And one more question, I had 1000rpm and bought 1500rpm spring but I saw some manufacturers advertising it like +20 %, +30 % etc. and what does it mean? +20% than stock? and what is kymco oem torque spring value?               

[woodcutter]

got almost the same result with new 737mm Bando as with 740( low quality vicma/dynaflex partially shreded but used just for this short test)  Didn't try another worn bando 737 I have or original too worn 729mm belt.
malossi 748 works but I used that one with multivar I gave my friend cos this is my second scoot. He needs it more  

Now when engine is running fine I'll try to play with rollers and rpm spring and maybe buy 3 sets of clutch springs (1000,1500 and 2000 rpm's) just to try and see.

    

[streido]

 o ordered the 2x set when i got my contra spring. Tried them all but ended up going back to the 1000rpm one. Found the 1500 helped better uphill but if i remember i lost some top end and acceleration. The 2000 was terrible for me and i actually went down to 20mph uphills i get 28-29 on using the 1000rpm. The reckoning is with a stiffer spring you use heavier rollers but after many weekends swapping springs and weights i came out with the 1000rpm contra and 5.5g rollers. Maybe when i fit a new longer belt next week i will need to rerune it again to get the best out of it. Getting a 750mm long belt from work for free to try out, if thats no good orcis too long i will order a 737 or 753 i think. Im sure my stock belt is a little too short now with the race variator.

Keep an eye on the new belt cos when i put an 18 wide belt in mine i destroyed itself within 1-2 months. I want to get 16.5-17mm wide and a 10-20mm longer than stock belt.

Btw, im sure stock contra spring is 750-800rpm if i remember correct.

[woodcutter]

if stock spring is 750 -800 rpm, no wonder I got flat spots on light rollers and new belt. But it might be spring lost it's stiffness and ready to be replaced after 25.000+ km's
Think I haven't had issues when scooter was almost new even with lighter rollers and original belt.
I like 1000 rpm too, so I'll try it on longer blt and different rolls

'bout belt, it's so cool you can get belt for test and see what's suits your ag, but 16.5 mm wide is, or close to a service limit.
my original one is 15mm wide, streched to 735mm now, so be careful not to buy a brand new item with properties of an used one 
While I was running old one, uphill and start was ok with no flats but top speed dropped to 60kmh and not a km more no matter how flat or how steep road were. and lighter rollers made it even worst.

Also, if you decide on wider belt, might consider putting washers/spacers to adjust front pulleys on belt and remove it as it get s thinner       

[woodcutter]

after I destroyed one belt I can correct myself, after saying some time ago, that belt angle makes no difference after initial running in.
It does and check overal quality + check width continuity of the belt on a few different spots along belt.

[streido]

I meant im going to get a 737 or 743 not 753 belt after i try the 750mm.

Before i fit it i want to use a guage to measure the gap  at clutch side pulley at the lowest point. That way i will be sure i dont get a belt that is too wide too go right down. The stock is either 17.5 or 17.7 i think but 18 is so close to 17.7 i dont think i should make much difference?