Piaggio hyper race on rexy frame, the true sexy rexy.

[808ministroke]

the Best upgrade I've ever done yet $60 for a new polini pwk 28!i was gunna save up for this exact one it solved my bog!!!!

a forum Member guess correctly Take a guess at who knew the answer....

[aeroxbud]

I brought a cheap replacement carb a few years ago. It would never run right flat out. Tried every jet under the sun. In frustration I brought a Dellorto. Run great straight out of the box.
I would never buy a cheap carb again.

[repherence2]

Dec 8, 2020 5:57:26 GMT -5 aeroxbud said:

I brought a cheap replacement carb a few years ago. It would never run right flat out. Tried every jet under the sun. In frustration I brought a Dellorto. Run great straight out of the box.
I would never buy a cheap carb again.

In my experience, i found that the fake Oko 28 came with the wrong emulsion tube. Once i replaced that, the carb was easier to tune.

[808ministroke]

Yeah the emotion tube is probably the key there was also the issue with the slide on On my knock off however as the slide was from a knock off of a knock off and actually from a 24 mm not a 28 with the added benefit that the coding was flaking off the slide in my Now entirely European engine doesn't need the choke on Chinese flakes.

Whoever is reading this this is as close to a copy right is on the night and get right now and if anybody wants to Maybe start organization with me just dedicated to helping people understand what aspects go into tuning as well as how to problem solve on their own and grow this counterculture As it is a great teacher for much more than mechanics and can keep a lot of kids out of trouble like myself, The name is gonna be.....


ALUMINATI !

 To be honest I really just think this is the coolest name ever so if it's nothing but a catch phrase that I've coin I can live with it.

[808ministroke]

so Search literally everywhere trying to find a set of taller gears there was a few sites in Europe which either I didn't trust or didn't trust that they would be in any way on time with delivery. I ended up finding some in stock@aplacethatineverthoughtidbeapatronofnotbecauseihaveanythingagainstthesepeoplejustbecauseimverysatisfiedtosaytheleastwithscootertuning.ca AnywaysScooter swap shop said that they had AM in stock on their site I made a call to themIt was actually pleasantly surprised that it was Paul whom I know from the videos they do. Anyways He said that the gears worry special order item but that all said and done they should be at my door in 2 or 3 weeks witches lot faster then I think I would have got from other sources also he was able to order me they gears that I really wanted that they hadn't shown on their site.
so i ordered the tallest primary gears I think that they make for this engine which are polini primaries 16/37, I had already done the math as I was eyeing these on another site in which they couldn't even tell me if they shipped to the US the math I had already done and I knew that with these primaries installed my final gear ratio would be 8.5:1 a huge step up from approx. 13:1 I'm not too worried about these being too tall as I've had 9:1ratio on A77CC identicle cylinder I'm actually thinking this would be quite the perfect ratio for me.
I didn't wanna go down to a ratio that wouldn't increase my top speed by much which is what I'm truly after with this gear swap, I did a top speed run the other night and yesterday both times maxing out at about 62 miles per hour with a very Old belt I was going to swap on the new one and see if that increases my top speed or not I wouldn't expect it to do much maybe an extra mile if anything How much do you guys think I can expect to gain in top speed Assuming my engine can pull it? If I don't get at least 5 more miles per hour at the top end I'll be truly Disappointed, I know that that's a lot to ask out of U single upgrade however with almost everything else upgraded to the extreme my extremely short gears world the thing holding me back the most I believe apparently I just found out that the ratio is so high because my engine was meant to run 12" tires Which I might consider doing in the future as it would allow me to put in a 12" front That I have that will fit my bike and therefore use its bigger disk brake but for now I just wanna see is close to 70 as possible

[808ministroke]

ever since changing to the polini carb it gave me back the ability to actualy remain at a constant low speed waaay more throttle control still with the response you want . thing is how the choke runs makes me think of a possible air leak at intake, what makes me wonder is how it will climb to a very high rpm if i leave the choke on after a cold start. i looked and the choke passage looks twice as big as on the oko could that be it perhaps? i went up from a 48 to  a 52 pilot jet when switching carbs also to be safe. when bike is completely warmed and i pull the choke it does exactly as i would expect otherwise it will instantly die out its just on cold starts i notice this consistently. oh yah so i swapped on a new wider maybe slightly longer last night and it was a bull out the gate i even was able to beat previous high score by 2mph.

[808ministroke]

switched back to a mux pg 4 & 5.5 gram rollers from all 5.5 so dropped 1 1/2 grams total, i dpesnt take off as hard with lighter rollers but i was curious about top speed and to my surprise picked up an extra 2mph! so far 64 is the fastest speed i have recorded so far this done on a flat straight road half tucked.

[808ministroke]

man i am loving this baby!
i noticed the belt was too wide so i switched back to the stock one and gained on the top without losing any take off, i hit 66 the other day and i thoughy my gps was broken went back the next day and without using up the entire legnth of road and not completely tucked hit 65 and on my atempt to try the opposing direction was cut short by a car but nonethless in alot shorter distance hit 64 . so i think safe to say the bike does 65 , that makes this officialy fastest bike ive ever owned.
i saw a crowd of dios and syms after the second high speed atempt while i was on side of road letting it cool and checking gps, i got soo exited felt like after a fist fight when your adrenalin pumps so hard you might puke, lol. when i caught them all at next light i realized they all were packing a girl. so i let them go and made a turn back home , only in Hawaii can you be cool enough riding a moped that a girl will actualy wanna ride on the back love it here!

[aeroxbud]

Good speed. What sort of RPM are you hitting at that speed?

[808ministroke]

Dec 30, 2020 19:51:17 GMT -5 aeroxbud said:

Good speed. What sort of RPM are you hitting at that speed?

around 12,000 - 12,500 tops. 
i have these beautiful primary gears i bought to swap that if i used current secondary gears would take ratio from 12:1 to 8.5:1



and i just got ba l from another rip and i hit 67 on these stock gears that the forum member and mechanical magican pitobread
told me were off a gilera runner i believe when ichecked they were 12:1 could have been even 12.5:1 either way i feel that this cylinder makes sooo much power that if i put in lighter weights it will have no problem getting right up to power band even with a like 40% increase i think and i didnt do the math thats a wild guess.

[808ministroke]

anybody have any words of caution as far as incresinf final drive ratio that much,12:1 - 8.5:1? this for now will continue to run 10" tires (120/90/10) am also thinking of switching front wheel for a bigger 12" wheel of same 3.5 " width so i can use the bigger disk on it and better calipers as well both would probably add years to my life, lol. i think it am look ok eeven thiugh i would rather go 12" in back with smaller front the back tire is such a high profile and the sho k mount is tall of a large frame vespa i think the stance should still look good, this thing handles sweeeet round corners especialy sonce it is stretched onto a fab mount freind does bomb ass welding.

[808ministroke]

okay so i got in the maiil the set of tuning needles from polini seems like such small variations dont quite know were to start is the longest needle the leanest on almost wot? is the diameter of the tip more important than at the top?
i think i may have worse problems than finding the perfect needle though it seems like my clutch area is making a rocking noise and i know ill have to get a recording but im getting this waah waah waah sound on deceleration sounds like if the exhaust bracket was loose and pipe was bouncing but its not. could this be ring related or reed related, is it flutterring ? backpressure? blowback? i have heard yhis sound o many fast mopeds before like brents even made a similar sound at wot run and others is this a sound that is normal in high end builds ? just dont recall hearing it before...

[captincvmn]

Best of luck tuning with your carb. I’m starting down that path. It seems like such a finicky thing and of course on my scoot I have to take off air box to do any internal adjustments and pull the seat bucket to turn any screws. PITA.

[808ministroke]

Well so far I have Changed the needle to a slightly richer one put it on the 2nd richest clip position End gave that a go with the STR8 velocity stack which has a fine metal mesh at the end for particles , I tried this stack with the stock needle on the middle clip and it hauled but it seemed like it was maybe you lean a bit and was when I noticed the WA' WA' sound the most since changing needles in putting the stack back on that sound has for the most part gone away and it is riding h Hard.

One idea of mine is that maybe the exhaust is somewhat clogged? H only maybe 4 months Old but has seen a lot of use in that time and I mix 3 oz per gallon3 mixWhich I think is somewhere around 38 to 1 or something but I usually use Mo to 800Is it possible my exhaust is getting clogged I'm thinking this because that's where the sound kind of comes from and on a very short ride a few blocks the pipe at the stinger was super hot compared to the engine in such.

[808ministroke]

well friends my scooter life may well have gone into a winter season , i was testing diff needles On my 3rd or needle I Used I made it to the end of my street before the engine cut off in a way similar to if the spark plug boot head come off .
However it was not so innocent, On attempting to restarted I realized the kick start was stuck .
I was able to move the crank slightly by turning the variated but it sounded really badd Yesterday I dismantled the Top End ofengine Quickly discovered There was many little bits of metal welded to the cylinder head and Crown of piston.



The only other change I had done was installing a state 6 easy turn Extended air mixture screw However I do not see this is the cause because I was able to get idle working decent in had installed this mixture screw a few days prior I also was switching over to a richer needle so I kind of doubt that was the issue either.
I had installed a velocity Stack about a week ago although I wasn't using it at the time it did have a Metallic mesh over aMeadow grate Which mysteriously went missing after about 2 days of use I figured it had just blown off or the ring of rubber holding it to the end vibrated off It doesn't seem like it would have been possible but maybe it had got Inhaled through the intake although The thicker metal with the bigger holes was closest to the carb and seemed sturdy enough that the simple suction of the engine could not have produced enough force to bend this into a shape that would have fit into the other side of the intake especially through the Reads Also this piece went missing A few days before this event happened in which I had been riding a lot and never noticed any issues
One of my theories is that the Right and left halves of the case simply started to drift or shift higher and lowerAs there is an obvious ledge both on the outside and inside of the caseThis would have created a massive air leak amongst many other issues still wouldn't explain how the Meadow The metallic pieces and got up inside.


However The cylinder Seems to still be in good shape with the piston The ring is stuck F in won't rotate And there is very slight damage to the One of the reeds both small and and big end bearings Seem perfect and there's C clip 7 not only stumped at what happened but how I should go about trying to rebuild.