LX50 Tuning

Hi Guys, a few questions please

Here is my set up, I have a vespa LX50 2t 2006
Malossi 70cc cast iron kit
gianelli smile exhaust
stock carb with 65 main jet
6.5g rollers

It feels like something is holding it up at around 40mph, the revs are increasing but the speed doesnt seem to.

I was told that my pipe didnt have a restrictor in it as i would be able to see a washer in the mouth of the pipe reducing the bore, all thats on the end of the pipe is an olive that joins to the block.

It does some spluttering when accelerating when cold, i have been told that this is because i took the brass plate out that goes between the carb and airbox? will i have to put this plate in when i fit my malossi 21mm carb?

I have on order the malossi mulitvar, flyclutch and belt. I didnt really want to fit a gear up kit as i want more acceleration than top speed.

Thanks guys

 

variator restriction?

 

if its the spacer that looks like a steel wedding ring? That's long gone....

 

Yeah rollers sound too heavy to me too...

Std weight on them is 6.4gram and when derestricted Piaggio recommend dropping 1gram.

 

could be a number of things

- carb may need re-jetting (happened to my mates)
- brass plate on carb may need removing ( this is a restricctor)
- variator restricted
- exhaust restricted, it WILL be restricted if it a fully road legal one, unless it has already been de-restricted(it will rev upto about 7-8thousand thn almost stop, the washer is hard to tell if its there or not, this it what happened to me)

by the sounds of it, a 65 jet seems very small to me, derestricted i had more than that, so with a 70cc kit aswell... im guessin its the jet mate

 

I put a 65 main jet in whilst i was running it in, stock was 53. the malossi 21mm carb has a 70 main jet. will fit the carb at the weekend. Does the main jet only really come into play with the throttle fully open?

Brass plate has been removed although there are varying opinions as to what this actually does - i thought it would restrict air flow, but some people say it is to meter the air flow to alow for a smoth acceleration - One theory, is it slows the airflow and prevents low-end over-fuelling but that`s just a theory. i did notice that with it removed, it splutters unitl the revs get to about 4000 or the engine is nice and warm.

the only restrictor i could find in the variator is the spacer i mentioned earlier, that went the day i bought the scooter.

exhaust - its a gianelli smile and i was told that you could see a restrictor in the end of the pipe (in the block end) reducing the bore to about 5mm - do you know if this is the case? because i cannot see anything like that in there....

as for the revs, i cant really work out how high they are going, they just seem to keep going, i've not had the revs die on me yet as i've not bothered pushing it any harder because it wasnt going any faster

Rollers - I went for the 6.5g as this is what the gianelli spec said to go for.

Oh well, guess I'll wait till next week when the multivar turns up, then i can fiddle with stuff.

Any suggestions would be greatly appreciated!

thanks guys

 

Brass plate ISNT there to restrict, its to direct airflow though the carb passageways on the newer 17.5mm carbs.. as without it the fueling fluctuates badly. However as your now running 70cc i would leave it removed anyway as youll be needing the higher airflow.

 

could very possibly be the exhaust as the resticter is very hard to see, i didnt see mine until a mate of mine pointed it out. this rerstricted mine to 700revs/40mph when i had my 70 kit on it...

 

Do you have any idea where it might be?

 

take the exhaust or the barrel, the part of the pipe going off to the downpipe will have, its hardd to explain, its almost like a spacer... tag welded onto the thing, ifyou can take a decent photo of it and post it on here ill try and look to see if there is one. or you can try my mates method... take it off, run your finger down inside the pipe and see if there is a step before the first bent, it will be about an inch down probly a lil less.

 

Thanks for all your help guys.

Its alomst impossible to find a decent pipe for this machine!

 

its probably a good pipe, just needs derestricting

take it to somwere that nows what they are doing, or be prepared to spend a good few hours with a hammer + chisel lol :w00t:

 

I know a bloke who owns a metal fabrication plcae, hes really handy with welding and fabricatinig bits. if i can find where the restrictors are, i'll get him to hack it about!

 

just inside the start of the pipe where it goes onto the engine, run your finger down the inside you will probably feel the step

its like a spacer that reduces it very slightly, tig welded onto the inside of the pipe, just grind it off and your lafin

 

Thanks Starkie, I'll whip it off again tomorrow, from what i can remember, you can barely get your finger down the pipe!

 

well, that didn't have the expected results.....

I fitted the 21mm carb, went like crap - wouldn't start untill i put the air box on. took the airbox back off and drilled the 14mm hole and stuck the little bit of supplied pipe in as per malossi instructions, went better. Before it was reving reluctantly and not goin anywhere. After the new hole at least it moved.

It goes now but seems really slow, worse than when it was a 50! the fastest it will go now is about 35mph, but seems to have less power, I don't know if its just me but it doesn't seem to want to rev as it used to, its ok up to 20 mph but then it just sucks.
i checked the throttle cable adjustment, that seems ok, do you think a multivar would sort it out or do you think that's wishful thinking?

thanks guys

 

Thats what i thought, but this malossi carb said that it is pre calibrated fro its 70cc kits.....