kitted puch magnum za50 whirring sound

my setup:

1980 magnum ii

21mm dellorto racing

93 main, 60 idle

proma gp

malossi 4 petal intake

polini 64cc


i put it all together today and i am amazed at the speed / acceleration. out performs my tuned vespa grande (and a lot quieter too).

anyway, my issue is that i hear a slight "whirring" sound when coasting above 30 mph. it sort of sounds like a fast spinning...hard to describe. I just never heard it on my cvt vespa.

i heard it before i kitted, so it's not a new issue, just noticed it a bit more with the higher speeds.

it doesn't seem to affect performance (the moped runs quite fast and smoothly), but i was just wondering if this is an issue I should address. If anyone (i'm sure there are lots of za50 experts here) has experienced this or knows what this may be, please share.


Re: kitted puch magnum za50 whirring sound

is the sound coming from the clutches, or bearings? its not a rattle right... that's good. the whirring doesnt worry me too much, but the pucks wear out in the clutches,,, so see if youhave any play in there.. have you taken apart the motor at all? i've heard stories after rebuilding motor, the seal between the cases is gone and there's a thousandth missing, causing the cases to rub against the bearings..

Re: kitted puch magnum za50 whirring sound

no i haven't taken apart the motor yet. but i got it after about 6000 i'm not sure about its past.

it's not a rattle, more of a whirring.

sorry for the noobie question, but how do i get to open / inspect the clutches?

Re: kitted puch magnum za50 whirring sound

Re: kitted puch magnum za50 whirring sound

if you just grab the magneto and see if it rocks back in forth in and out slightly your pucks are wore out.. but with 6k on em i guarantee that... but i dont think it would cause a whirring.. but maybe...

Re: kitted puch magnum za50 whirring sound

Wecantfindthetreasurewithoutthemap /

Sometimes when people take just the side of the trans off they forget to put the gear shaft /clutch bell pre-load shims back in causing the gears to slightly mis align and do whirring sounds and also there are two different clutch bells that when are mixed up you definetly get that sound ...but you said you havent taken it apart so maybe it was serviced back in the day or ?....polini+two speed=fun

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