Any Help Would Help... Piaggio typhoon 70cc... FIRSLY I COMPLETLY REBUILT THIS BIKE MYSELF... My bike was running fine with my old setup (check below) but exhaust snapped and I got a free stage6 pro rep. Now it works fine on the stand but it does like 3mph from pulloff and takes like 30+ seconds to reach 15 -20 mph max. I been reading on forums and everywhere about springs and rollers so I bought everything and tried Various combinations but nothing seems to improve ??? Set-Up / when previously working. Polini 70cc cast iron kit, Ngk BR8ES spark plug, Dellorto 17.5 carb / 72 main jet (65 stock), original air box / malossi red sponge (snorkel removed), Polini variater / 5 gram rollers (correctly spaced), Stage6 clutch and bell / white stage6 springs, Polini 20kg torque spring, Extra Items But shouldn't make a difference... TNT reed block, polini green reeds, top racing 3 piece gear kit 20%, athena unlimited cdi, naraku full circle crank. Sfk bearings and seals, Purchased after reading forums... Set of 3 stage6 clutch springs, polini 23kg torque spring, Box sets of rollers, stage6 jet pack 60 - 82, 2 spark plugs, new belt,
I noticed that you got the exhaust for free, is it new or used? If it is used it may be gunked up and need a clean out, also have you checked to see if the restrictor washer has been removed.
the stage 6 pro rep comes with a restriction in the down pipe coming from the bore also the polini cast iron will struggle pulling the gear up and affects your acceleration a lot andhe stage 6 pro rep is suited to the stage 6 streetrace and sport pro it has to rev quite a lot and has a narrow power band so is quite difficult to set up
Im not sure how your strength of pulley springs affect the variator weights but with the original spring around 4.25g-4.5g on the rollers should stick you right in the middle of the powerband once you get moving. I think the hardest clutch springs you can find would be necessry with that setup, something that bites around 7k rpm to get you moving nicely. Without the gearup it should also be much sharper when pulling away
The gear up kit should not have much effect on acceleration as the variator should take care of it. The pro rep does come into it's own at higher revs and does lose out at lower revs to the likes of a Leo Vince zx . Have a look at the graphs on the Pedparts Blog about exhausts on 70cc sports kits. On my Aerox 70cc streetrace I have tried a pro rep and a Leo Vince zx and find there's little between them at low revs but there's an advantage to the pro rep at higher revs.
It was used but I re-packed the end can and TRIED to clean the expansion chamber also the restricter was removed. I got the red stage6 clutch springs on there at the moment they are the strongest ones. I no it's not the gear-up my last set-up had v.good acceleration. So I gotta get it to rev higher ? Ok I'm waiting for a new throttle cable because I'm been reving it so hard I snapped it.
Try taking at least half the packing out of the end can, you could well be choking it through not letting the exhaust gases escape fast enough.
over packing the end can would make no difference as long as the is a tube in the thing for gass to flow down.
If the bike was running well before you changed the exhaust then it's quite likely to be something to do with that. I remember a forum member whose bike ran like shit and wouldn't pull after he had repacked the exhaust. He had overpacked it and that had caused a restriction. As a first step I would recheck the packing to make sure it is not causing a restriction. I've found that it's often the simplest things that cause the biggest problems. If the exhaust checks out okay then I would turn my attention to the variator. The pro rep exhaust performs well at higher revs but it does lose out on power at lower revs, I would try a lighter variator weight to help the engine get into the powerband before the variator is fully changed out.
