Advice needed from experienced 4 stroke engine modifier

I am about to undertake a heavy duty conversion and need someone who understands the modification of scooter engines like there ABC's. If anyone knows of a friend or member who can offer sound advice can they PM me? I am going on about my 200 Runner st and have high performance parts lined up but I can help but feel I am missing something vital to ensure the machine runs sound. List of parts are in my post in maxi scooter tuning. Titles 'Gilera runner st 200 modification'
Cheers.

 

What do you want to know?

 

http://www.scootershack.co.uk/threa...era-runner-st-200-to-an-st-300-monster.32849/

Link to the parts I am buying for my conversion. The carburator kit and cylinder kit contains a lot of parts. I am unsure if I am missing any parts that are needed as it is hard to get info on a full engine upgrade.

 

Go for a race camshaft and how about a Malossi cylinder head?

 

Hi, I drive a modified Runner st 200 and have the following work done.​

- Dr Pulley Variator 14g sliders​

-Dr Pulley Clutch​

- Malossi X Kev Belt​

- Polini Speed Bell​

- Akrapovic Slip On Exhaust​

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My question is, do I need to up jet? I CANNOT find any info on the st 200 main jet size, although I have been​

informed that Piaggio/Gilera etc use the Keihin CVK Carburator and it states it has a main jet of 92. Dellorto make​

main jets compatible for this Carb and next size up is 95.​

The bike feels fine when running but that doesn't mean it is not getting damaged... Can anyone advise me on the ​

new jet I should get or if re jetting is even needed? Would all these parts have my runner running lean or rich?​

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Should I leave it as is? New air filter needed?​

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Any advice would be greatly apreciated.

 

You'll never know until you ride it whether it needs re-jetting or not. You will have to do plug chops at different mileage intervals to check whether its running rich or lean, or even bang on. Reading through your other posts, if the slip on is the only thing that you have changed so far that might make a difference to the running, then its quite possible that you will have to up-jet slightly, maybe two or three points.
But, the question is, will you re-jet it yourself or have the garage do it for you?

 

None of those mods will affect jetting

 

Even changing the exhaust Ramo?

 

Some people say the end can would affect it noticeably.... Some do so..., I Have a mechanic who does it all for me. I ain't got the time or the technical skill for working on bikes. No mechanic seems to be arsed helping me out when I enquire about the possibility of having to upjet or balance fuel/air... I doubt the end can has cause a huge inbalance. I assume it is expelling more air so it 'could be a tad lean?

 

I got my scooter tested on the dyno and everything looks great. He did say that only when full throttling and the revs push to 9k does it run slightly lean but nothing to worry about unless I am doing it too often. When I give it full throttle the revs go up to 9k very fast so could I squease out a little more juice if I increased the main jet from 92 to 95/98 or would that be too much to make it slightly rich?

 

It would'nt hurt to go for a 95 main.