Modern Vespa

Hi all

Since I don't have a good response on my other post I try to find another answers.

I just put a Tecnigas maxi 4 on my Fly and I got worst perfomance than with my catalytic exhaust. When I go WOT there's no power and takes age to build up speed. Normally with this kind of diaphragm carbs they dont need to be upjeted in my knowledge. I don't know where to start.. the first 3,4 seconds it accelerate good and after no power. Could it be the SAS not blocked yet that cause this lag?

Thanks guys

Someone please ?

after you had the bike on its side to install the pipe did you clean out the oil from the airbox and intake?

how was it running immediately before changing the pipe? not months ago, not when you got it, but *exactly* right before.

besides the pipe did you do anything else?

Right before installing the pipe quite slow ... It takes age to build up speed. I didn't change anything else. At 50mph it's shaking and rumbling. Today I've removed the airbox, clean it out and change the sponge inside going to see if it was the culprit. I didn't block the SAS yet. Planning to do it right after reputting my airbox.

so right before you installed the pipe it was running like butt, you installed the pipe and it's still running like butt?

the problem isn't the pipe.

sas is inconsequential here. find out why it was running poorly *prior* to installing the pipe. also, don't tip you scooter on the side for maintenance work. they don't like that.

No sorry the scooter was running right before the pipe install.

so it was running right before you changed the pipe and now it doesn't.

so something you did in the process of changing the pipe is causing poor running.

have you cleaned the airbox and intake tract and re tested?

did you touch anything else in the process of swapping out the pipe?

Tomorrow morning I'm going to try it.
I've let it sit for the day and tonight. The airbox was cleaned and reinstalled. I've blocked the SAS too.

I don't know what else apart from leaning the scoot on the side is causing poor running. The pipe was bolt on.. remove the old one and install the new.

clean the airbox out, make sure the intake tract is clean as well. clean and re-oil the air filter and make sure that the filter box lid is properly sealed.

if that doesn't return it to normal running then something else is messed up. just installing the pipe will not have that dramatic of an effect on the performance.

Perfect will report 👍 thanks

Still taking age after 40kmh to get to a merely 80... I think its not hitting the powerband is it possible? Lighter roller possible solution ?

I'm out of ideas

Greetings

It's not possible that the catalytic one is better... what else could I have done to worsen the perf...

There's effectively a need for a bigger jet with the Keihin 26.. the spark plug is somehow very white.