Hi Comp issue

Anything related to Vespas... ask tech questions, post helpful info, or just read and learn.
registered user
Posts: 3
Joined: Mon Apr 12, 2021 11:09 am
Main scooter: VespaSS180

Finally installed and started up my 230 pinasco build on SS180 block. Runs really well..but..compression is so high it’s a nightmare to kick off and even bent my MHR stand plate trying! Squish is 1.8mm as recommended. 2 choices I see, either have the head reprofiled or drill a decomp hole above the exhaust port. Anybody done this? seen them done on Lammy kits. Or is there a 3rd option?
Engine is built for touring set up. SS180 gearbox with BGM 23T clutch. 28 mm SI carb, 2kg Atomic flywheel and Sip 3 box
registered user
Posts: 859
Joined: Mon Jul 07, 2014 10:34 am
Main scooter: lambretta li 125
Location: Tyne and Wear

I'm not familiar with vespa motors, but an often disregarded aspect is the gearbox ratio.

As capacity increases, you can usually lower the gear ratio, which (in the case of lambrettas), has the same effect as a longer kick-start.

Maybe your 23t clutch has already done this?
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