Modern Vespa

Now this is one of the best readings I found on this subject (General, not 2 stroke specific):
https://www.crankshaftcoalition.com/wiki/Reading_spark_plugs

Your jets seem way too rich, picture is unfocused but seems lean at 1st glance, only a lurker here

I was just looking at my plugs trying to chase airleaks and what not.
I pressure tested after a rebuild, all good. I spray every square inch of my scooter with brakecleaner spray, I get no rpm change whatsoever!
My idle returns back almost instantly and no fuel in oil of course.
But my idle is never steady , it seems to search a bit.

Today I went and got a new plug for my first chop , I read it has to be new, put it in but road about 2 miles on it before my WOT then clutch and kill.
I didn't bother to chop it yet because my electrode was as white as snow without one spec 9f darkness or carbon or burn or anything. Just a new plug with pure white on it. What am I doing wrong?

It does seem a tad rich at 135 doesn't it? I can't figure it out. Some people say ride it and quit chasing it but until I have a full grip on what I'm doing in relation to the scooters reaction I can't leave it like this..
Anyway thanks Mr. Lurker😁

Sounds pretty good to me, I heard the tickover change pace a little in there but unless there are other signs (which it sounds like there aren't based on your earlier post) I don't know if you should lose sleep over an air leak.

Non destructive plug chops have meaning yours is difficult to see clearly but the grey appearance indicates it could be lean. Is the hole at the bottom of the float bowl drilled? If it's not been increased to 2.0mm could be an issue. There is some belief there's a bottle neck with the hole at the bottom of the float bowl which leads to the jet gallery restricting flow for even a 135 main jet which seems large for your build spec.

Sounds normal.

How many turns out is your mixture screw?
Try the edge of where the revs drop (warmed-up engine).

Well embarrassingly enough I tried drilling that hole on my other carburetor, hence the new carburetor!
I'm not sure I'm ready to spend another hundred and $135 on one of my mistakes again. Especially when I have not read anywhere on this form that anybody has been at a 135 and not fouling too rich you know what I mean?

Looking at my plugs I've never had a "rich " looking one
Jetting is , 120/BE3/135

Also you need to be using premium gas on that kit. Not the cheap stuff. It affects the ignition and will cause issues if you use the lower octane stuff.

First thing change the BE3 (lean) to a BE4 (correct). Then check your jets are sized actually as numbered. If you really have an AC120 and really have a 135, that plug should be totally black.
If it all checks out it's a fuel supply issue; tap, pipe, float bowl hole, fuel cap, etc
More to it than the hs plug.
But one thing your right about is it's not as it should be.

That's something I hadn't though, although I always use the best gas available.

Just one more thing concerning the carb float chamber bore to main jet stack, as it is referred again (above) that needs to be drilled larger. SI24/24E standard bore is 1.5mm, Scooter Center has a BGM SI24/24E all tuned up carb with a set of features for highly tuned engines ... the bore is 1.8mm, not 2.5mm! So I sent them my setup asking if I needed to drill the 1.5mm bore to make use of my main jet on my setup:
BGM 177, ported engine, filter drilled SI24/24E, Polini extended intake crankshaft and variable ignition, SIP Road 3, 55/160 and AC160/BE3/140

Their short and straight answer:
"you can expand them, but you don't have to."

Why do I always insist on opening cans of worms?

So your suggesting I not worry about doing it?
Or atleast it won't hurt me 8f I don't expand it?

Will check it tomorrow regarding edge of rev drop but currently its 1 and 3/4 turns out.

i will say that every time i've messed around with jetting based on plug color it basically hasn't worked for me. i think the color issue is problematic because of the "chop vs tip" issue, it's problematic because on 2-strokes there's also burning oil "in the mix" that changes the coloration pattern, and synth vs dino, plug temp yadda yadda yadda blow my brains out it complicates what color to expect and where.

Of course I do think you can still make good sense of whether you are in the *ballpark* based on plug color. It shouldn't be a sooty mess, it shouldn't be bone white. But dialing it in to the final end points... over the years, and with the gentle patient nudging of more experienced members on here (for which I am eternally grateful), I've come around to the "seat of the pants" tuning approach - start with a crazy big jet, and work down based on how the engine actually performs, find the best behavior, and then bump it back up maybe 1 size for safety. I guess if I was building higher performance scoots for myself that might not wholly suffice and I'd bring CHT into the mix too, but my scoots are city drivers and country cruisers, not track demons

for the float bowl, drill out by hand using a pin vise, you won't screw it up.

https://www.amazon.com/Bastex-Precision-Vise-Drill-Twist/dp/B072M35LDZ/ref=asc_df_B072M35LDZ/?tag=hyprod-20&linkCode=df0&hvadid=309813767497&hvpos=&hvnetw=g&hvrand=15374824360936545156&hvpone=&hvptwo=&hvqmt=&hvdev=c&hvdvcmdl=&hvlocint=&hvlocphy=9061190&hvtargid=pla-569740741362&psc=1

i will say that every time i've messed around with jetting based on plug color it basically hasn't worked for me. i think the color issue is problematic because of the "chop vs tip" issue, it's problematic because on 2-strokes there's also burning oil "in the mix" that changes the coloration pattern, and synth vs dino, plug temp yadda yadda yadda blow my brains out it complicates what color to expect and where.

Of course I do think you can still make good sense of whether you are in the *ballpark* based on plug color. It shouldn't be a sooty mess, it shouldn't be bone white. But dialing it in to the final end points... over the years, and with the gentle patient nudging of more experienced members on here (for which I am eternally grateful), I've come around to the "seat of the pants" tuning approach - start with a crazy big jet, and work down based on how the engine actually performs, find the best behavior, and then bump it back up maybe 1 size for safety. I guess if I was building higher performance scoots for myself that might not wholly suffice and I'd bring CHT into the mix too, but my scoots are city drivers and country cruisers, not track demons

you need a full reset. and you're going to have to change stuff/spend money for the right parts to get this dialed in.

fast flow tap : WILL GET!
drill carb : WILL DO
get the right jet stack and a handful of mains : I HAVE A SET OF MAINS FROM 115 TO 138,
I HAVE A 190 , 150 AND 120 MIXERS ,
IDLE JETS I HAVE A 55/160, 50/120 AND A 52/140

buy some set drills (or a gauge set, or both) with a pin vice. : ORDERED A NEW SET OFF AMAZON!

confirm that your fuel line is correct diameter and length : PURCHASED AND INSTALLED FROM SCOOTERWEST 1 MINTH AGO

confirm that your vent in the tank cap is clean and clear, hell, even open it up : VENT IS CLEAN QND CLEAR!

run the correct plug for the application. B7 is too hot, ES is the wrong reach : LOL, WILL INSTALL MY NEW NGK BR8HS!

are you running a spaco or dellorto? : NOT SURE PURCHASED 2 MONTHS AGO FROM SCOOTERWEST

does it have the *correct* jets--: HOW DO I KNOW THE CORRECT JETS? ALL JETS ORDERED WERE ORDERED FOR AN SI24/24E


some came with T5 jets : ?????
. what air filter are you running?
is it drilled?
NOT SURE THE BRAND BUT THE HEART SHAPE ABOVE THE JETS IS DRILLED. APPEARS TO BE FACTORY HOLES!

you have to be specific, otherwise you'll just be chasing your ass.

having run what you're running, you'll likely wind up in the mid too upper 120's and a you'll want a B8 or 9 plug depending on the type of riding you're doing. adjust your timing accordingly, and if you don't have a degree wheel get one.
TIMING CHECKED 17 TIMES , AT 3000 RPM IM ABOUT 19 BTDC AND 18 AT IDLE. POINTS GAP CURRENTLY SET AT .35

tons of great info here to follow up on.
AGREED BUT FUNNY ENOUGH IM FINDING ALOT OF CONFLICTING ADVICE ASWELL. IVE SPENT CLOSE TO 8 HOURS TOTAL ON THE CRAPPER READING EVERYTHING I CAN FIND ON THIS FORUM!

IVE HAD TWO PEOPLE ADVIZE A BE4 IS RICHER THEN A BE3 BUT IN THIS FORUM THERE IS A COMPREHENSIVE WRITE UP ABOUT JETTING IT POINTS OUT IN NO UNCERTAIN TERMS A BE3 IS RICHER THEN A BE4.
AS AN EXAMPLE IS ALL IM SAYING.
I SWEAR THE MORE I "LEARN " ABOUT VESPAS THE DUMBER I BECOME.. I CANT AFFORD MUCH OF THAT

You already did the hard part

What I see is the correct plug now, correct 19mm reach, looking very lean, apparently. I would cut off the threads and check if you have a dark ring on insulator base, 2 to 3 mm…

If it's white then you're definitely lean

Ps: and btw, you NEED a fast flow tap

Your Malossi 166 uses a short reach plug. For NGK, it uses a B8HS. B9HS for extreme conditions. Get that long reach plug out of there asap.

think your head is for hs plug. Put the short reach back in. See the dirty line on the threads of the es?

As said, drill the carb by hand. Between 2.1 and 2.5mm is ok. There is a whole spectrum of info on the subject but this gives the best reliability once up over 15 bhp.

You need a fast flow tap. I like the SIP 2.0 with reserve position. Take it apart when be you get it and check its smooth and debris free.

Your Malossi 166 uses a short reach plug. For NGK, it uses a B8HS. B9HS for extreme conditions. Get that long reach plug out of there asap.