help needed with pinasco 177 cast iron three port

Howdy from NZ

the above kit siezed on me 10kms from home

24 dellorto with 114 main and be4 atomiser.timing 18...b9 plug never over three quarter throttle. 4% mix. cut crank (11mm )

SIP want me to send it backbefore they will repllace it. At $100 its not ecconmical.

I still dont know why it siezed. Experienced eyes have said the piston was too tight(2 thou) and the compresion very high

does anyone have the specifications so I can measure what I have and see if its a manufacturing problem

I feel its better to spend the $100 fixing what I have (I am sad about that) but at least I will have a scoot a gain

Does anyone have the specs so I can take it to an engineer to fix

Has anyone else had problems


only a minor sieze with scuffing on the piston sides.I have pics but how do I post them?

please help


Hi, unfortunately the pinasco cast iron usually has too tight piston as you noticed, and this easily leads to sieze. Pinasco is not always so serius and reliable as it seems, they make mistakes and the worst of it is that they do not always correct them and keep on selling products that may create problems as it is the case here. In general, for cast iron cylinders, before installing the kit it is always good to measure the difference in diameter between the base of the piston and the cylinder, which should be about 0.1mm for good reliability, I bet in the 177 pinasco cast iron it is much lower.

Besides, 114 mainjet is probably too small, unless you have a calibrator smaller than 160, and I also wonder why you used a BE4; the standard setup of the si24e 160/BE3 is pretty good. If you have 160 calibrator you need more or less a 118-120 mainjet with standard exhaust, more with sport exhausts such as sip road. Anyway, though the mainjet was small, in my opinion you seized for the former expressed problem (too tight piston), as you did not drive at full throttle (under the influence of the mainjet).