Piaggio AC 2T problem! :(

We measured the belt off an old Hexagon (10" wheels) and it was the same length as the Polini 180 belt (we keep it as a stand by for sprinting as it`s "run in" )

Yes it will work fine out of the box so to speak and should sit properly right at the top of the rear pulleys giving you back your accelleration.

Malossi`s belt part # M612737 is also listed as fitting:

This product is compatible with the following models:-

APRILIA SR125
APRILIA SR125
GILERA RUNNER FX 125 and SP 125
GILERA RUNNER FX 125 and SP 125
GILERA RUNNER FXR 180 and SP 180
GILERA RUNNER FXR 180 and SP 180
ITALJET DRAGSTER 125
ITALJET DRAGSTER 125
ITALJET DRAGSTER 180
ITALJET DRAGSTER 180
PIAGGIO HEXAGON 125 with 10 INCH WHEELS
PIAGGIO HEXAGON 125 with 10 INCH WHEELS
PIAGGIO HEXAGON LX 125
PIAGGIO HEXAGON LX 125
PIAGGIO HEXAGON LX 180
PIAGGIO HEXAGON LX 180
PIAGGIO SKIPPER 125 with 10 INCH WHEELS
PIAGGIO SKIPPER 125 with 10 INCH WHEELS
PIAGGIO SKIPPER LX 125
PIAGGIO SKIPPER LX 125
PIAGGIO TYPHOON 125
PIAGGIO TYPHOON 125

So there you go, if either of these two belts dont sit correctly then youn either got the wrong centre pin in your variator or your torque driver is jammed half open, but I suspect the belt.

 

Thank you very much for helping me with this guys, I think your right in saying its the belt, I cannot return this belt to the shop because I fitted it myself.. Bastards.

So Im going to get a polini 125/180 belt when I get paid, but will it be ok to run my bike how it is for another 2 weeks or so? I guess its been like this for a while but its not gonna knock the drive shaft out isit?

The torque drive WAS semi seized up, but I think I said in the first post that I took it to bits and re-greased everything and shes moveing smoothly now.

 

Right guys, today I picked up a Genuine Piaggio Hexagon 180 drive belt, the 125 belt I had was infact the correct belt to begin with, after triple checking.

The 180 belt has made a difference being slightly longer. BUT its Still NOT riding the lip of the clutch pullys, its higher up than before but still sitting far too low into the pullys.

But atleast its rideable, off the mark its pants, still wont rev up at all untill around 40mph but now she picks up abit faster than before, id now say its a fast as a de-rizzed 50cc 2T upto around 40mph then she starts performing like a 125.

The only thing I can think of is the torque driver not returning fully, if I rev the bike on the stand, then look at the rear pully thru the cooling slots in the tranny case, it clearly moves in and out very smoothly but on return to idle the belt is still not in the correct place!

However, when I take the rear pully unit off and remove the belt, it springs right back, its asif the width of the belt wont let it return OR the contra spring is getting too weak and cant push back hard enough to move the belt up?

Anymore ideas on this guys?

 

Time to get the verniers out then.

Measure your rollers, make sure they are 19 x 17.

Make sure you have the two washers on the variator the right way round, one is thicker than the other, it goes....

Oil pump drive cog.
Variator and centre pin.
Thick washer.
Outer pulley.
Thin washer.
Kick start cog.
nut.

If this order is wrong or the rollers are too big the belt won`t sit all the way down in the variator and so ride too high in the torque driver.

If this all checks out then it could be a weak torque spring, replace it with a new std or a Polini (+10%).

 

Hi blue dwarf, thanks for your input you are one helpful person. If you havent already checked my pics on page one, look at the one with it all layed out in order. Is anything missing?

My washers seem to be the wrong way round according to your list above.

On my bike its: 18mm nut, kickstart washer,SMALL THICK washer, Fan pully, THIN LARGE washer, belt, variator pin, variator, oil pump spacer.

The thin washer sits perfectly in the fan pully slot, the thick outside washer wont sit in the slot as its smaller in diameter.

Cheeeeeers!

 

There dos`nt seem to be anything missing but the variator spacing is wrong.

As long as the thick washer sits over the crank and on the end of the pin and fits inside the machined recess in the outer pulley thats where it needs to be, your variator halves are too close together making the belt sit too high in the variator and too low in the torque driver.

There is no hard and fast rule and you can play with the spacing as long as the kickstart still catches the cog and there is enough thread to tighten the crank nut and fully secure the outer pulley.

Swap the washers or source a couple more and space the variator out another mm or two.

 

Hmmm, yeh Il try swapping them round. But theres bearly enough room on the crank for the kickstart cog as it is, another mm or 2 would mean I cant use the kickstart cog. So I best hope the thick outer washer will work if I swap em round.

The thin washer sitting in the recess in the outer pully, fits perfect as you can see in pics, but the Thick washer behind the kickstart cog, wont fit perfect in the recess for the outer pully as its smaller but thicker..

Would that matter?

 

No it won`t, it seems some where along the line some one has lost a washer and replaced it.
The two washers should be identical size but different thickness, one 0.5mm that goes behind the kickstart dog and one 1mm that sits in the back of the outer pulley.

I know I keep saying this but have you measured your rollers? this extra 1mm room given by 19mm rollers plus the correct spacing of the washers will make a difference.

 

Hi guys! :grin:

I think we are getting somewhere now with this! Last night I swapped round the spacers, thick one behind pully and thin infront. Made a BIG difference, still not as perfect as I'd like but not too bad now.

Then today, I fitted BOTH washers between the front pullys, and no washer infront.. But funny enough the kickstart still reaches the cog and works fine. This has made it even better!! Shes taking off well now, still wont fully rev out untill 30mph but its getting better with the more spacers I add.
From 30mph onwards shes offskies, nice and revvy, can blip the throttle without it bogging out now. And its instant acceleration now.
Just 0-30mph is a little flat still.

Ive ordered a bunch of 0.5mm spacers to pack up to make the correct space. Then im going to machine my own spacer for between the front pullys, as piaggio no longer make the spacer, they only still make the 0.5mm spacers.

So yea I think we've got it now, going to order new rollers soon to be sure i got 19 x 17's. Then just gonna setup the spacing.

And Id like to thank everyone whos helped me with this, especially Blue dwarf and Minor for their input and time!

 

Amazing how shifting washers and 0.5mm shims can make a difference to the set-up eh? :grin:

 

Yeh 0.5mm can make a huge difference, I know its still not right because im running no washer behind the kickstart cog, but hopefully I can get this set nice when I get my washers tomorrow and machine my own spacer, with a washer behind the kickstart cog :grin:

The belt is almost at the top of the clutch pullys now, another 0.5mm-1mm on the front pullys should let it ride the top of the clutch pully. And obiously when I get the correct rollers too this should help.

 

I got the variator spacing spot on now! Added one too many spacers earlier and the fan pully rubbed against the tranny case but no damage done. Removed one 0.5mm spacer and it ran wicked! She really flys off the line now and blerts right upto 65mph on the clocks, im running 2 x 0.5mm + 1 x 1mm spacers between the pullys (so 2mm in all), and one 0.5mm spacer behind the kickstart cog.

So all I need to do now is get a 2mm spacer machined and job done! I still noticed a little flat spot between 20-30mph but I think its down to the rollers, they have flat edges for a start and may possibly be the wrong size still. So gonna get fresh ones soon.

 

If you are running 20 x17 rollers and you replace them with new 19 x 17 rollers you`ll have to remove 1mm of shims to correct the spacing, but now you`ve got your baseline spacing you have the choice of running 19 or 20mm rollers and just add or remove 1mm of shims to compensate

 

I had the same "old style" engin in my Typhoon project, and it has the same variator setup like your, so I think all spacers is in it's right place.

http://www.scootershack.co.uk/viewtopic.php?f=8&t=4833&start=135

 

Shes a minter now guys!!

I've fitted a fresh set of Malossi 19x17 12.5g rollers, removed the shims and fitted my new 2mm spacer, ran shit.. removed it and fitted two 0.5mm shims. Job done shes a gooden.

Running like it should now! Really fast from 0-30mph, no flatspots now, then really revs out from 30mph onwards to a topspeed of 65mph on the clocks, which im guessing aint that good because wait till I get my gps on it.. Im guessing no more than 60mph true speed, my zip70 done that

But this could just be the gearing, because it picks up extreamly fast its actually caught me out a few times already!

But I have found another niggle in the system.. Today I noticed fuel dripping from the overflow pipe onto the ground, only 1 drip an hour or so but still.. From a cold start the engine fires straight up, choke cuts in, ticks over for about 30seconds, then when the choke cuts out it wont rev, just bogs and dies but will tickover. once its warmed up it'll clear up and rev. (its been doing this since i got it)

Im guessing that the fuel dripping could be causing this. it only drips when the engine is turned off and as above, 1 drop an hour or so.. but anyways once you start the engine that overflow pipe clears.
I think its a mikuni VM20 carb, im not gonna bother fucking around with it so i wanna get a new carb, would a 25mm carb work on a standard 125? Or should i just sorce a delly 20.5mm?

 

Koso or OKO 24mm flat slide carb would be good

 

hi got a problem with my zip wen the bikes cold its great as soon as it starts to warm up it wont go no faster than 30 mph iv got a technigas exhaust on it any help would be great

 

i run an oko 24mm carb on my 70 runner, and its a brilliant little carb

dont really seem much thirstier than my old dell 20.5mm....

 

Yea minor its doing just what you said your typhoon is doing, I could try heavier rollers but I noticed the clutch has little meat left compared to a new one, and I might get a new torque spring too and see if that calms her down abit.

But yea flys to 30mph, then screams from there onwards to 65mph its kinda anoying because its quite revvy just cruising at 40mph compared to anything else ive rode.