Free and Inexpensive Scooter Performance Mods

[TBR125]

Hi, to any performance nut.

Has anyone mounted an Airspeed indicator on their scooter for true performance data. Would that even work in turbulent traffic air flow?

Feel free to critique/criticize.

[jeeves]

Does it backfire on deceleration?

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[TBR125]

That question sounds like experience. The short answer, yes.

My bike currently runs rich and without the catalytic converter if I decel to quickly it does pop a time or two. I'm designing a baffle that should minimize the shock-wave if I can get enough pressure flow data.

[jeeves]

That question sounds like experience. The short answer, yes.

My bike currently runs rich and if I decel to quickly it does pop a time or two. I'm designing a baffle that should minimize the shock-wave if I can get enough pressure flow data.

I'm having the same problem.
I have an Technigas 4scoot exhaust. Bought it because the original one was in bad shape and wanted something that's legal for road use.
The engine breathes easier, but it started backfiring.
The strange thing is it didn't do it from the beginning.
Checked for leaks, couldn't find any, and changed the exhaust gasket ring, but it still backfires on deceleration.

Maybe I need to repack the exhaust...

I thought that by putting on a less restrictive exhaust the engine would tend to run leaner?



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[TBR125]

As far as I am aware, any carbureted engine when perfectly tuned momentary runs rich at some place during decel causing backfiring in any exhaust system that doesn't have a catalytic converter. With glass pack mufflers the shorter the chamber the louder the pop. I live in an area where pick-up trucks are straight piped so my scooter exhaust is not comparatively loud.

[Fogie]

Hi, to any performance nut.

Has anyone mounted an Airspeed indicator on their scooter for true performance data. Would that even work in turbulent traffic air flow?

Feel free to critique/criticize.

I owned a sailboat for 35 years, and therefore have experience with wind speed indicators; in fact, I still have a hand-held model (that's the only kind I can imagine being able to install on a scooter). I would expect that the majority of hand-held units would be made for sailing, and therefore calibrated in "knots"; so, you'd have to do measurement conversions (to MPH or KPH, depending on location). By the way, one knot equals 1.151 MPH, or 1.852 KPH. Also, the range of wind speeds that are anticipated when sailing, are much lower than experienced on a scooter; for example, 50 MPH (over 80 KPH) is in excess of 43 knots. I doubt that a hand-held unit would be designed to measure accurately at speeds approaching that magnitude, since, in my opinion, most sailors wouldn't care about the details of such a blow, because they'd be too busy scrambling to find their life jackets. So, I would conclude that a practically-sized wind speed indicator would not prove useful on a scooter, but I'm quite willing to stand corrected.

[TBR125]

As I don't want a cup anemometer on the handle bars, I agree with the impracticality of a unit intended for general use. I have been using knots as my standard speed unit because of my work with aviation and sailing in the BSA Sea Scout unit.

Thanks for the info Fogie.

[Fogie]

As I don't want a cup anemometer on the handle bars,

Hand-held units don't have cups, but they're still impractical; for example:

https://www.globosurfer.com/best-anemometers/

[jeeves]

Why not use a GPS?

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[TBR125]

I have a GPS but air resistance is what limits speed. As in 5kph tailwind =5kph faster. Knowing relative wind speed is more accurate for engine performance check.

I stripped an exhaust stud in the head and am working on it. With the muffler back on I will be ready for jetting. I should have the info from that posted this weekend.

[TBR125]

Hi,

The oiled UNI filter is on.

[TBR125]

Another picture.

[Iahawk]

wow, just saw this thread...I seem to miss clicking on the Technical / How To section...

great mods! Your ability to do all this for so little $ is extra impressive. Can't imagine going 78mph on a scoot!

[TBR125]

Patience and hand tools can work wonders. My dream scoot would look like this.

[TBR125]

My carburetor is re-jetted! I swapped the main and pilot out a few times with test rides in between and settled on a 115 main and a .38 pilot. I will take a long ride tomorrow to finalize the tuning.

As a side note, I always expect a job to be harder than first thought, but still, the carb tuning was the most complex thing I've ever done to the bike. I feel a tad bit invincible. I will have performance data tomorrow and will see what the 56 dollars for jets, air intake, and muffler really did.