Greetings to all vespa lovers, I had my px150e fitted to a pinasco 177 cylinder kit after installation I had it compression test the reading I got was at 130 psi. Would you say this is the correct psi reading?[:smokin:]
I just finished to install the Pinasco 177 kit on a PX 150 2005 (US)
Before getting into the compression issue, let me point out that in order to match the cylinder porting on the kit, I had to weld aluminum on the cases cause they had not enough material to do it right. As a result, I had to front the case mouth like 0.4 mm to make the surface even & ready to receive the kit. I also shaved the base of the cylinder head with valve grinding compound another 0.2mm
The geometrical compression I got is 8.88 / 1
This is how you do it:
With the engine out, & piston at top dead point, pour oil with a syringe thru the sparkplug hole until it gets to the base of the plug tread. My combustion chamber absorved 22.5 cc.
Then take the displacement of the kit: 177.3CC and add it to it = 22.5 + 177.3 = 199.8
Then: 199.8 / 22.5 = 8.88 (which is what I wanted for a touring set up)
Just plug your own figures on the ecuation and you can know yor bike's (nnominal) compression.
It's usefull to have it as a parameter and to compare it with the std. set ups.
Regards to all
Juan.