Hello peeps, :tup: Just a quickie, this is the set up Ive decided on Laser X Pro Enki Induction Polini 70cc cast iron kit Polini Crankshaft and Bearing Polini Speed control kit and Outer front pulley Malossi CDI And obviously different jet sizes, roller weights and clutch springs But what carb size should I go for, It's going to be a daily ride so I want to keep it reliable and reasonably economical, the bloke at my local bike shop thinks a 17.5 but Im not sure, I was thinking maybe 19 or 21, what do you lot recommend. All advice will be most appreciated :mrgreen:
if your using a strong crank fuck an iron kit.. grab an evo and a big carb... c21 pipe and start smiling
Cheers for the replies people :tup: Ok so I was looking at a Malossi MHR replica and a bgm crank but I decided against it for 2 reasons Vertical set up exhaust problem, According to the exhaust and barrel thread the Laser X pro will work, But I've heard other people on this forum say that this exhaust will strangle this sort of set up. Saint Johny recommend the Doppler S3 but according to the exhaust and barrel thread it's not suitable for mid race use, Some people on this site have said that Top Performance Nardo will work well and the Scooter Attack tests seem to back that up, but other people have said the build quality is poor. So can anyone recommend a road legal exhaust for a mid race VERTICAL set up And the second reason is.... It's a original 1991 BWS it weighs less than my nan and she's been dead for 26 years, Im 6.3" to fit on the scooter I have to sit right at the very back of the seat, which means my arse is hanging out over the back wheel. So do I really need that much power. The reason I want to change the crank with a cast iron kit, is I dont trust the original 18 year old crank
Id go for a 17.5 delly, the only real thing i noticed different with that and my 21mm was how much fuel it drank, was marginally faster. Oh and ditch that enki reed block and get a Stage 6 v-force. That Enki will do jack shit
well, you obviously didnt set it up then did you... 17 as fast as a 21? and your ginving people advice?
Minor Confusion, You seem to be one of the more clued up people on this forum, so what do you recommend then mate
I said the 20.5 was marginally faster than the 17.5, on a sport it hardly seemed worth it with the fuel it used
hence it wasent setup... id go 21 min on a sport/rep, 25 on anything more interesting/single ring. i personally run a 25 on an iron kit supposedly "too big" ye it drinks, but its not slower than with a smaller carb thats for sure
if you're willing to spend the time to make things work, then it is going to be faster on a bigger carb at the top end, FACT
"well, you obviously didnt set it up then did you... 17 as fast as a 21? and your ginving people advice?" well how do u set it up cos im thinking about sizing up
putting a carb on means changing EVERY variable.. usually heavier rollers for a bigger carb (altho these can go ether way) big carbs are pre jetted roughly for bigger engines so the pilot jet is too big, the needle too thick and the atomiser/slide cutaway is incorrect.. you can get them neer on setup out of the packet but there a little laps/full throttle dont feel right, altho its still faster than a smaller carb. setup means the ENTIRE engine, ANY change to an automatic engine means the gearbox HAS to be ammended to use the new power in the diff rpm its now sitting. its taken me a week to get mine close wiht the new kit (usually does take 5/6 rolelr changes, god knows how many needle an jet changes aswell as diff contra springs and the like.. THEN theres diff belts, spacing the pulley different. blah blah blah. not a SINGLE part can just be thrown on and playd with.. not ONE. even a reedblock or even reeds will need a SLIGHT tweak of the idle mix at a bare MINIMUM
i ran a 20.5mm dellorto on a polini iron 70 kit for a year... very torquey set up, and pretty quick top end, when set up properly i couldnt see any benefit to having a smaller carb on my bike... well unless you wanted to go slower of course
Too many variables really to just copy some one elses jet size on a different engine.... 75 on a modded airbox running autolube 78 on a modded air box running pre-mix 85 on an open filter with autolube 88 on an open filter with pre mix also depends what pipe your running too...
And for a rep setup the best exhaust you'll be getting is a Top performances nardo, came 2nd to the yasuni c16 in scooter attacks tests. There isn't much else for the verticals available, but as they're light at least you ain't wasting half your power just to move. And i haven't had any experience with a TP pipe, but unless they're like a Techniwank or a PM tuning comes in a year, lasts a week exhaust, it surely can't be that bad with some tlc.
