Right so, Recently i was bought a pulse scout 50cc for my birthday and have been riding comfortably derestricted for a little over 4 months now, However my moped seems to be running extremely slow. Ive tried to Derestrict it and have tuned the moped to the right intakes (With help of my dad who is an Ex-Mechanic). However itll hit 35/40 Flat And 40/45 Downhill, Your Probably thinking great thats good for stock. But the problem is that when i go uphill, On a Hill with a fairly steep gradient itll hit 5/10Mph, Big change from the 35/40 i was getting on flat. When driving it up my road im hitting about 15/20 (This is fine) However my friend can hit 30-40's uphill and he also rides a 50cc with near to simular specs (I have checked) However he has an aftermarket exhaust (THIS SHOULDNT MAKE A MAJOR DIFFERENCE) Its not running at low revs we have upped the revs so it stops idling, However the problem is only uphill it seems that there is little to no power (I think i could walk faster than that) Some things i'd like you to help me narrow down due to the fact ive done the research and i want to know which is worth my time and which isnt: Checking the: Drive Belt (Possible Replacement) Rear Pullen Unit Restriction Screw Hose into airbox (if it has Three small holes remove it) Discs between variator screws (Remove Collar) Air Filter ( Does it run better without the air filter ) Heavier Contra Spring In Clutch ( My clutch collapsed therefore it was replaced with a near to new one ) If the Pistons/Cylinders are worn Weak Mixtures Carb Setup Properly Possible Upgrades to Buy: New Airfilter High Performance Spark Plug New Vacuum Hoses Fuel Line Hoses BBK Aftermarket Exhaust Aswell with this when my bike reaches max rpm's on a flat it feels asif it cuts back and stops accelerating and itll keep that speed flat (This can become annoying as itll happen suddenly but will only affect speed by -1/-2 Mph) Any Pointers? ----------------
Roller weights and contrast spring. what your mentioning about hill climbs could be due to slightly heavy rollers and a stock contrast spring. what happens is the heavy rollers get thrown outwards early on so they engage the higher ratio more quicker, all good on a flat land ride. BUT when you come to a hill and the engine starts to lower its rpm those rollers dont realease much pressure so keep the belt high up on the variator and because the stock rear contrast spring is fairly weak the belt says low in the rear pully, this means as your hill climb starts your in the wrong gearing ratio. if your able to , we could do with what weight rollers are in your variator at this time, did you change them out when you derestricted ? a contrast spring say a blue contrast spring will be 30% more stiffer than the stock spring so when you roll off the throttle that spring will force the belt to a lower ratio and pull the belt in the variator down giving you a low ratio , ideal for hill climbs. Stock pipe V sports pipe : your stock pipe is tuned for low rpm due to it being heavly restrictive , even some stock pipes can be derestricted but they still lack that Punch your expecting. a sports exhaust has been fine tuned to produce power at a certain rpm range aka the powerband spread, its usually around 8000rpm to around 9500rpm depending on what exhaust system you fit. the key part is the sports pipe has a larger ID pipe to allow exhaust gas to escape quicker and a expansion chamber thats tuned to help force some of the unburn fuel charge back into your engine so you get to use all the fuel and air the engine sucked in via the carb, with a stock pipe this acoustic wave is very little to extinct so your always loosing a little bit of that fuel charge and its expelled from the stock exhaust as emissions. With a new sport pipe you will need help from dad to REJET your carb to allow extra fuel in so you get a bigger bang and more horsepower that pipe produces to. Re-cap roller weights ideal to be around 5g - 6g 1k contrast spring nice sub £100 sports exhaust BBK its upto you but if you go this route you will need to replace the carb with a larger one and still have a sport exhaust fitted, you will then want a uprated variator and maybe even a gear up kit so you gain the extra speed and optimize the power produced by the bore kit. Hope this helps and im sure other folks will be alone to offer advice and tips
Roller Weights are stock, Only thing ive changed is my clutch. Upon changing my spring and roller weights would the exhaust need to be an immediate change or not?
No fella you need to weigh your roller weights, just one will do , if you find you have something like an 8g roller installed, just swap them all out for something around the 6g mark, you should see an improvement on take off speed and hill climb, Dont change the contrast spring yet just try some new rollers first see how it feels. lighter roller weights means the engine has to gain a higher rpm before they are thrown outwards and start to push the belt higher on the variator and at same time pull the belt into the rear pulley . im sure you will see a difference in pep lower down and your rpm will be more constant through the ratio change low ratio into high ratio. the aim of the lighter rollers is to get the engines rpm up where it produces the most horsepower and hold that rpm all the way to max speed , the clutch springs just tell the clutch when to open out, and the contrast spring helps to keep the bike in a lower range when the rpms and torque drops off ie when you start a hill climb the rpm falls the rollers slide back and the contrast spring pushed the belt higher up in rear pully giving a low ratio gear ideal for climbing hills. in human terms we are balancing doing ten keepy uppys while rubbing our belly and tapping our head all at the same time , but a little more easy with a scooter lol. And let me say Welcome to the Scooter Shack Kaaaz
Got a 72CC BBK ready to install, Also got a sports exhaust fitted, Bought 4.2g Roller weights (With it running at higher revs with contra spring + 72cc engine i figured this would be more beneficial) 1k Contra Spring bought New Drive belt bought New drive boss( Goes inbetween the variators and the nut) New air filter Upjet for my carb (5% or 10%) --------------------------------- Problem when replacing variator is there is a little spacer inbetween where your meant to screw in the nut to the frame (To lock it in gear) The variator locking tool wont screw on due to this and also the teeth wont connect to lock it into place, I was told to drill it out (As pliers wont work twisting and pulling) Any ideas? Its like a spacer but its well placed in there
sounds like a seating bush to line up the variator cover. other way is to find a friendly mechanic with a impact gun, you run down on scoot with your tools, pull off side case, he zips off the variator nut, you do your bits needed, then he zips the nut back on for you, that will save you a lotta headache getting the locking tool to bite the toothed fixed pulley half, plus your not going to need a torque wrench to retorque the nut back on the variator just throw him a fiver for use of the impact gun , or offer to get him a fizzy pop can and a sandwich from garage as payment to help you out , keeps his workshop uncluttered from overwork on your bike lets you get a hand at wrenching and he gets a free dinner .
Dad did it with an speed-gun (Impact gun) and did that, I now pull 55 downhill and i still have to fit my air filter and my bbk I raced a 125 and was right on his arse. Before i was the one furthest back, Slow startup but as soon as that 1 second is passed, it flys.
glad to hear your wrenching worked well , take it easy down hill you need to hold back or you start to over rev and thats not to good for motor
Do you not have issues when pulling up a hill from a stop? Got issues with mine, runs really fast on flat like 90km/hr. I can get up a hill but need some momentum. But from a stop, i just cant pull away and i dont know why. I currenlty have a stage6 70cc sports pro, technigas sports exhaust, stage6 sports pro variator, stage6 medium torque spring, 1000rpm clutch spring, anf 4.5gm rollers. I think the previous owner of this scooter has up geared final drive as well. Any help, thanks
