Rev's / Gears

[mickingle]

Now i have my sito plus on the standard PX, im already dreaming about the end of the warranty period (or considering doing things that can be reveresed before the next service.) Thats not to say i'm not happy with the vespa as it is, but know it could be a lot better.

Question :-   When i set off, and i notice this more when the scooter is cold,mainly in 1st and second, i reach a certain point on the throttle when the revving stops and i get a flat sound.

So, is this down to having the restricted throttle slide, or is it the CDI that is restricting the rev's.   I'm not technically minded but would like to understand what it is that is causing it if its either of those things.
 
As yet, i havent changed the air filter to a drilled out one, which i will do at some point if its recommended considering the restricted CDI.

[rab]

Id be looking at changing the cdi for a non restricted one and putting the origional back on if you need to take it back to the shop .goto keep the warrenty happy lol

[henri]

doesnt sound like "bogging" from over jetting so will go with rab an say swap ya cdi for a normal 1 ,your way more likely to hit the limiter ,7000rpm i think,in 1st n 2nd , do you know the number of slide in the carb as i thought the cdi was only restriction , havent heard about a restricted slide , when 125's were first restricted some manufactures did put a plastic ring above the slide so it couldnt open all the way,soon got rid off mostly, an some restricting kits for 33bhp bikes are plates with smaller bores behind carbs ,with air filter off an throttle open if ya look down carb bore slide should of disappeared totally to the front/cable side.if not its restricted in some way. H

[mickingle]

Thanks for all the replies. That does make sense that's it's the higher revved gears. I'm not certain but pretty sure that it's always when it's from a cold start more so than pulling away from lights etc. I read about the throttle slide somewhere else and then saw De-restricted slides for sale (sip) I think. By the way this has happened with both exhausts so everything was totally standard as a cat model when it was doing it with the 1st exhaust. When I get chance I will have a look and take some photos. Thanks again

[mickingle]

www.ekmpowershop2.com/ekmps/shops/readspeed/readspeed-zeus-vespa-px125150-cdi-6216-p.asp

Not cheap but sounds like i'll need to do it. Next question - are the easy to swap out?

The latest production of Vespa PX125/150 scooters now come supplied with a CDI with a waterproof multi plug, and although functional, these CDI units now have a rev limiter at approximately 7000RPM.
This rev limiter will introduce problems if you wish to fit a bigger cylinder kit or exhaust system. This will make any performance modifications pointless as most cylinder kits and exhaust systems will require a higher RPM than 7000 to reach full potentia
Priced at £79.99p the Readspeed "Zeus" CDI is a cost effective solution to this problem.

[sbwnik]

Before you do anything to it, change the plug down a number to get a plug that heats up more quickly. It could just be slightly oiled and not up to heat, my 200 shows very similar characteristics, always has, until it hits operating temp, unless I run with a slightly cooler plug.

[mickingle]

Thanks for that, great advice. I did order a couple of spare plugs in different sizes so ill take out the one thats in, see what size it is and fit the lower one if i've got one.

[fredperrybruce]

I've always had this problem when the scoot has been left awhile to cool down,when I first had a Vespa I asked the same question thinking I had a problem after trying to f**k around with jetting and cdi units I found out it's perfectly normal when the engines not up to temp. Can't wait till winter when the first half mile feel's like I'm on a Lawnmower. lol

[mickingle]

Brilliant shared advice. Cheers lads.

[mickingle]

As i was up extra early (kids fault) before setting off today, thought i'd leave start her up and leave her running. Gave it 5 mins tickting over, im sure the neigbours will have enjoyed it at least. Set off down the road, and it was the same as normal. It seems to take a couple of times going up through the gears, and then the next time round its already corercted itself. Doesnt help that i live just off a pretty steep hill so the 1st mile or so are snails pace.

ps not altered the spark plug yet -

[mickingle]

Aug 20, 2014 9:54:24 GMT sbwnik said:

Before you do anything to it, change the plug down a number to get a plug that heats up more quickly. It could just be slightly oiled and not up to heat, my 200 shows very similar characteristics, always has, until it hits operating temp, unless I run with a slightly cooler plug.

So, i finaly got round to changing the spark plug on Monday night from an NGK B7ES to an NGK B6ES.

After the third cold start run with the lower plug number, i can confirm it's solved the problem. Rev's through the gears nicely from the off. Cheers Nik