Alright people, got a little problem, my standard belt was worn so I tried out a Polini Kevlar, not very good. On hills the revs dropped and it crawled up, so I bought a new standard and put it in. Now my bike accelerates up to 30mph nicely but when it gets to 30 it just holds back, even downhill it will only stay at 30, then randomly it picks up for 2 seconds then holds back again. With the Polini Kev I had 3.5g malossi rollers, now I've got some cheap 4.5g in. I'm running a standard 62 jet, Malossi clutch (white springs), Hebo NG Performer exhaust, original 50 bore. Was just wondering what the problem could be, is it the jet or are the rollers too light/heavy? it's just weird how it does it when i put a standard belt back on it. All help is appreciated.
Try the lighter rollers with the Polini belt. The Polini might be slightly harder, or wider, raising the gearing, so compensate by dropping the roller weight.
Put 3.5g malossi in with the standard belt, alot quicker but its revving really high, there a bit worn so i have a little flatspot still (or maybe i need a tiny bit heavier?)
Try them with the Polini belt. Even better, try the Polini belt with a new set of 3.5 rollers. If the Polini is wider, or harder, it will ride up the front dishes slightly more, and spread the rear dishes slightly more as well. This will slightly raise the gearing, which could explain why your heavy rollers are struggling.
first, if you are running standard jetting on an aftermarket exhaust, it's not going to like that. check your plug colour but i'd suggest upping your jet size a little. second, it sounds like your motor is down on power to me rather than a transmission fault, mainly because with 4.5 gram rollers it should be about right not flat. it will rev its nuts off with the 3.5s in, try mixing the 3.5s and the 4.5s to give you a 4 gram overall. Personally i'd get my compression checked, it sounds like a flat motor to me.
i think i got the same problem with my bike and my bike seems to be over reving but still goes feking quick upto 30 and then seems to hold back havent riden it properly yet only up my road so it might be fine on a longer run
Polini belt with 3.6g hebo rollers, alot of flatspots. Done a compression check, thats fine, had a new bore only about 1k miles ago. Im thinking the rollers need to be in between the 3.5g and 4.5g, so buy a few sets and try them? Only thing that can be slowing me down can be the exhaust port I think, badly restricted. I've de-restricted the pipe, only one restricter at the manifold yes? EDIT: sorry, forgot to add that the spark plug's a light brown colour, looks perfect to me?
my hebo only had 1 at the manifold but i dunno if that goes for all of them. might be worth checking the end can just in case
just checked my plug again and it seems to be white now, went down to nearest garage and they gave me a 72 jet, put it in and its bogging (i guessed it would - im running a 62 at the moment). Anyone know roughly what size jet I need? I was thinking a 68? Luckily, the garage said I can take it back and try different ones at no extra charge imp: de-restricted, 50s, malossi clutch, polini reeds, hebo ng performer if anyone was wondering thanks.
