Modern Vespa

Now I am concidering up Grade my standard 125 PX vespa with a sip 2 but Hay can't see any improvement this setup Will make as l have already drilled out the air filter and change the cat part for a replacement manifold ! Is the box part restricted as well ?? Any advice most welcome 🤟 soulboy74

An exhaust pipe can make a big difference, you can move power and torque to be useful at a different RPM. Included a few links to various testing that I'm aware of.

As for a dyno of a stock exhaust with catalytic converter removed or not might be one in here not sure, wasn't something I was researching. There are a few comparisons of a stock non catalytic exhaust versus an upgrade.

https://www.google.com/search?q=vespa+box+exhaust+test&oq=ves&aqs=chrome.0.69i59j69i65j69i60l4j69i59l2j69i57j69i59l4j0i67j0i273j0i67i433j0i20i263i433i512j0i67j0i273j0i67.1496j0j4&sourceid=silk&ie=UTF-8

https://www.scootering.com/the-vespa-big-box-exhaust-test/


https://en.blog.scooter-center.com/nachlese-auspufftest-bgm-big-box-touring-bbt-big-box-sport-bbs-scooterlab-uk/

I advide/recommend/suggest that you use the SEARCH function.
This (and other questions) have been asked (& extensively answered) numerous times over the years

The road 2.0 does make a big difference over standard box, its the cheapest bang for back you can do, as is having drilled air filter. 1 to 1.5 BHP increase with road 2.0 and about 0.5 for the filter. When you think a standard px125, depending on model has a measly 8bhp on a good day, a 1 to 1.5 bhp is quite a high power boost percentage. If that's all you are going to do and not kit, its a no brainer. Read the blurb from sip, the facts they state are accurate IMO, used on on standard 125, very happy, used on kitted 177 PX, still very happy.

https://www.sip-scootershop.com/en/product/racing-exhaust-sip-road-20_24166200

Thanks for the heads up 👍 my standard jet main was a 96 standard ,m now I have drilled out the air filter l have put a 98 main jet in ? Does that sound right ,! Or should I have just kept in 96 one ?

1 or 2 pts up for drilled filter bang on so 98 is fine .

Thanks for letting me know just don't want to go to high up jets ! Like most are saying ! Didn't think it would be much bigger for such a small up Grade ! Sip road 2 next month and go up to ? 101/102 ish sounds about right to you ? and do l need to do anything to the rest of the jet stack ? Does the oil pump still delivered the right amount of 2 stroke for the engine with the up jetting ? Best regards soulboy74 🏴󠁧󠁢󠁥󠁮󠁧󠁿

101 or 102 is fine. As a rule of thumb on standard px it's 4 pts for road 2 plus 1 for filter , so 101 is good but on my px125 when standard went to 102 as when I gave it a good hard WOT run wanted it to richen up a bit as plug was pale brown not chocolate so 102 sorted this . No other intervention required on jet stack. You will notice the difference, even the old Sito plus was superior to standard pipe . I'd happily buy another road 2 when mine bites the dust.

Thanks for your help and heads up on all vespa tings man !! My sparkplug was a dark chocolate brown ish before the filter drilling modifications ! Standard set. Now it lighter just off White ! But no build up ; needs a good run out before the summer months so I can read the plug more correct ! a bit richer is better than a bit lean is that Right ? Thanks guys for your help us Brit's always need your help 🏴󠁧󠁢󠁥󠁮󠁧󠁿 the best country in the world USA 🇺🇸 best regards soulboy74

You are correct bit rich is better than bit lean. If plug is already white put a larger main jet in before a good run out. To lean will seize motor and leave you walking home.

If its near white its lean but have you just put the 98 jet in but not run out yet, is the plug colour based on driving the drilled filter on a 96 or 98? Yeah, rich your engine wont go boom, lean your engine can go boom. Its more the danger, seizing at any speed is not fun. If you feel your engine dying pull the clutch in straight away. My px200 seized many years ago as i was too lean and it spat me off and pillion as didnt have time to pull the clutch in, the back wheel just locked as the piston seized.

I have no idea on jetting for your scoot, sorry.
Last time Speedy had a "standard" SI carb it used a 142 MAIN.

Nice one 👍 thanks again for your help and yes it is running well so far just need a good day riding for a good time to read the plug correct !! Light brown ish is good yes ,! Getting ready for the spring weather hopefully very soon out here in the sticks of England there no other scooter riders out where l am so you guys are my gang to ask cheers soulboy74 🏴󠁧󠁢󠁥󠁮󠁧󠁿

Once your road 2.0 is on, stick a 102 main in, it will be fine. You might want to richen up the pilot very slightly by just adjusting the god damn difficult to get to mix screw , but id leave it well alone for now. See how it all behaves, runs. The type of adjustment you might need on the mix will be very small and that very small movement you could use some long snoop nose pliers to get hold of the pilot screw to maybe do a quarter turn rich.

Got it 👍 yes I have decided to go with the sip 2 at the weekend and got a full range of jet's 102 was the one I was planning on going with first ! Wheel off or flat tyre ?? Just wondering about that one ! Just hoping that standard one come out as easy as my teeth lol 😉 and there will be no problems just a big smile clunk click l hope it fits just like sip says if this doesn't work and I don't hit 50mph l going back standard 48 mph okay thanks for your heads up on all vespa tricks best foot forward soulboy74

You don't have to full take out wheel. Loosen the wheel nuts so they can be removed by hand . Loosen the exhaust manifold bolt. Put something on ground under exhaust like an old pillow so when it comes off it doesn't crash on ground and damage . If you got a spare wheel on side remove . Jack up the back under the rear engine case , but only enough to lift wheel off ground few inches, if you don't have a jack get somebody to lift the back end slightly and wedge some bricks under it. Undo the wheel bolts fully, you can then rotate the wheel anti clockwise and the wheel stand in place on ground so you can get at thr exhaust bolt into frame. Remove the exhaust bolt. With a blunt piece of wood and hammer tap down on exhaust near manifold to cylinder , it will fall off, hence the pillow to catch . You're ready to go. Get the exhaust mount to frame roughly in place whilst lining up manifold to cylinder exhaust stub. Push through the bolt to frame just to hold in place , don't tighten . Go round to engine side and with the piece of wood under the down pipe gently tap the exhaust up as high as it will go up cylinder exhaust stub. A rubber camping mallet is best but wood and hammer will do. Then tighten up the exhaust bolt to frame. Don't over tighten as you can bugger the caged bolt on the road 2.0 making removal next time problematic. Tighten up exhaust manifold . Rotate the wheel clockwise so each wheel stud enters wheel, when all on obviously tighten wheel nuts. Start her up and listen to the lovely pop pop of your new pipe. With your jets in go and thrash it's arse off and come home with a content grin on your face.

Ps so to check your actual gps speed against Speedo in case Speedo not working correctly get hold of gps speed plus or something similar app . Run the app and stick in your pocket. WOT scoot 4th on a long stretch and make note on Speedo of highest indicated speed. Pull in somewhere and see highest speed recorded on gps app. Good luck

Are thanks for that it all seems a good bit of advice most welcome yes I will give it a try your way over the weekend coming up can't wait l have been looking online but it not the same as reading how others did there's and they always seem to be in a rush job ! Going to get it right first time ! Do l use any type of exhaust sealer on the stub ? and the springs l know how one to the fly wheel gos!! But Hay how's the other one connected to ?? Any advice most welcome soulmate's stay lucky soulboy74 🏴󠁧󠁢󠁥󠁮󠁧󠁿

Well you can use a sealant yes, heat resistant silicone, or something more expensive like Permatex Maximum Temperature RTV Silicone. The springs, well mine arent on there anymore, but i seem to remember one went from a bracket off fly wheel cover to engine lower right to the mount on the exhaust. Then i think the other one went from the mount on exhaust to the plate over scooter stand, but i could be confused with the polini one i had on?!?!? Definitely one spring goes to the flywheel cover, theres a small flat bracket and spring in the SIP road 2.0 box.

Yeah got it 👍 yes I will use some copper grease l think it is called ! And I will have to look at wear it connects to the stand under when I am down fixing it on cheers for the heads up already got it up on the Axel Jack and two brick loads more room now!! I think I might have to take that wheel off you know not much hand room to work properly okay you GI l will give you the heads up after work and test ride 🤟 soulboy74

You can literally roll the wheel back off studs and half off wheel will rest against the wheel hub and makes it so easier getting back on if jacked up. So wheel is off enough to get exhaust bolt out , but as wheel steel remaining under body of scooter you can roll it back on to studs dead easy . It's not so easy sliding wheel completely off unless you got scoot high and you don't want it rolling forward crashing off stand if doing it alone . Handy to have somebody with you just to support scoot and even lend you hand lining up manifold whilst you position the exhaust to frame.

What year the PX is? Swapping to performance exhaust is really give you noticeable performance, of course with correct jetting. Also don't forget to get a bigger main jet. Mine was from 92 to 110 main jet.