EXHAUST PORTing | vespa TUNING | POLINI 177 | FMP-Solid PASSion |

[@alexfong5388]

Hello from Barinas Venezuela, is possible to do this mod with a Malossi 177 sport cylinder ? Thanks

[@FreakMoPed8]

sure!

[@charcoalacab7065]

when you widen the exhaust port do you also enlarge the diameter of the collector of the cylinder? does it have any sense to just increase the length of the port without matching the increase of the area?

[@FreakMoPed8]

you mean if i also work on the transfer ports? no i never do. dont have the knowledge for this. just exhaust port adjustments are fine as tractor vespa cylinders always come with small ports = potential for more power.

[@charcoalacab7065]

@@FreakMoPed8 sorry No, I mean if you grind also the walls of the outlet port, where the flange is connecting to the exhaust chamber. An increase of the inlet-exhaust-port-area should be compensated with an increase of the outlet-exhaust-port to match the rule (10-15% more at the outlet), isn't it?

[@FreakMoPed8]

Yes should be widened also fully trough but this is quite limited for vespa. It also show a good effect like this

[@adamstaniforth1829]

With opening the exhaust port only, (small amount) will I need to adjust fueling? Thanks, I'm new to tuning. It's a 50special with a d.r.75cc changing the exhaust port from "t shape" to "trapezoid" shape.

[@FreakMoPed8]

To the side no, to the top yes

[@FreakMoPed8]

But depends on if its npw set correctly or not 😉

[@adamstaniforth1829]

@@FreakMoPed8 thanks, I'll do the sides for now. Order some jets and then do the top. Great videos btw.

[@danielepatane3841]

How long is expected to last that heavily modified piston? Because the idea is perfect but I don't think the piston is sturdy enough to last long.....

[@FreakMoPed8]

never had a failing one. as long as u dont touch the main structure, the strengthening beams, its all good.

[@danielepatane3841]

@@FreakMoPed8well it's an headache because you give me the start to spend some money and time that I don't have....🤣

[@Rahulkumar-dq8jh]

Petrol kaphi kha rahi Kiya Badal jayega

[@tonitorner5002]

Hi, I have a px 200 with original cylinder. Since a short time ago i have picking problems with the gas at 1/4-1/3 I tried changing jets and the problem is still there. Is this an exhaust broblem?( I'm thinking about buying a tsr vortex) Do you advise me to tune the exhaus port? How many mm wider? Thanks

[@FreakMoPed8]

can be a lot of stuff. Clean carb first.

[@aureliacrasset4776]

magnifique. merci

[@paansukarjo90]

what is the timing of the exhaust now?

[@FreakMoPed8]

118/176 longstroke 60mm

[@pkg996]

Wow!