Sport exhaust slows scoot down

[ThehardcoreFTW]

Where to begin?

I bought my `07 Agility 50 about 6 months ago, 32 000 km`s on the clock.
When I bought it I changed oil, checked everything for damage and wear. Luckily I didn`t find anything except that I had a hole where the air filter is supposed to be supported, whenever I go over a big bump I hear a little rattle because it isn`t properly fixed to the scoot now.

Anyways, I bought and installed a Leovince exhaust a month ago, and eversince I did that it takes way longer to get to top speed. I can`t seem to find a reason/a way to fix it.
Does anyone know a reason why that happens?

Setup: Cut CDI, smooth boss, 5.5G roller weight, de-restricted air manifold, leovince exhaust.

[Mr. Paul]

When you increase the engine airflow by installing a high flow exhaust, you must also increase the available fuel to take advantage of it. Right now you are running too lean. Try putting in larger carburetor jets. This should help a lot. Running too lean is not good for the engine as the combustion  burns too hot and can scorch the valves/piston.

[ThehardcoreFTW]

Problem being; I can`t change my jets, the screws to open my carb have no profile, can`t find a way to open them other than drilling the screws out.
Would it work to just turn the adjuster screw anti-clockwise, as that causes the mixture to get some more fuel?

[CROSSBOLT]

Yes, for idle.

Karl

[ThehardcoreFTW]

The air/fuel mixture screw only has effect on idle? So I could just screw it all the way open, and nothing will happen to the performance?

[Mr. Paul]

The air/fuel mixture screw only has effect on idle? So I could just screw it all the way open, and nothing will happen to the performance?

Karl is right. The air/fuel mainly affects low speed operation. Would not help enrich the mixture. Are you saying the four screws on the bottom of your carb are rounded and have no indentations for a screw driver? I have never seen one like that. If that is the case, get another carb (can be found cheaply) and get bigger jets for it. I would not recommend operating a scooter with too lean a mixture.

[tortoise]

Are you saying the four screws on the bottom of your carb are rounded and have no indentations for a screw driver? I have never seen one like that.

! No longer available

[Mr. Paul]

Well, I have seen one now Tortoise. Urdman!

[blue]

Get a unsealed 20mm carb.so you can tune it in right.

[ThehardcoreFTW]

Are you saying the four screws on the bottom of your carb are rounded and have no indentations for a screw driver? I have never seen one like that.

Oo you access the jets on the bottom-side of the carb, not on the top side? I thought the jets were accessed through the top plate, with the two philips head screws.. xd
Thanks alot mate! Will try to open it sometime soon. 

What sizes would you guys recommend for the setup with the high-flow exhaust?   

[Mr. Paul]

They are on the bottom, where the fuel bowl is located. Best of luck.

[JayAre]

With all the derestricting you've done you the info is right more air flow should mean you need more fuel. But, take nothing for granted pull the spark plug & look at the color that will confirm what you need. Also when you derestricted did you make one change at a time & test so you know what the results are from each mod? Things don't always work like they should!

[ThehardcoreFTW]

...pull the spark plug & look at the color that will confirm what you need. Also when you derestricted did you make one change at a time & test so you know what the results are from each mod?

Only mod I didn't do was opening up the intake manifold, everything else was just done by myself. I had some backfiring w/ the original exhaust but the acceleration only got worse with the leovince. You can re-use the spark plug right (after you've pulled it out to check the colour)?

[Mr. Paul]

Only mod I didn't do was opening up the intake manifold, everything else was just done by myself. I had some backfiring w/ the original exhaust but the acceleration only got worse with the leovince. You can re-use the spark plug right (after you've pulled it out to check the colour)?

You could reuse the spark plug. Hit the contact points with a little sand paper and recheck the gap. I usually just replace them if I pull them. Its cheap and easy. Make sure you use anti-sieze on the plug and DO NOT over-tighten the plug. I had to repair a stripped head on my People. Not fun. 

[JayAre]

Unless your plug is black, wet or the electrode is deforming it can be reused. When you pull the plug it will be white if it's running lean. Go one or to jet sizes bigger. Brown or black it's rich, check you auto-by-starter/choke. Run it & see if it helps your top end, & pull the plug after you put some miles on it you're looking for a light tan when your jetting is right.