Racing crank

Right, would it be possible for me to use, a pk125 xl crank, for what i believe i’ll eventually need for a 130 kit, with my new 75 kit. On my pk 50 s, as it sounds like this could be my best option for saving cash, and getting a smaller earbashing.

Also, should i get myself a copy of norrie kerrs, vespa tuning?

I believe the cranks are different. The conrod on a 50 is completely different. Also on smallframes there are two different size tapers. The xl has the larger one. Now I think of it the xl crank might be the same conrod wise.
The cheapest option for more power is a replacement engine.
Norries book is the nuts even if he is a twat.

Cheers guys, might just get a new 50 crank then. And go with what everyone tells me which is getting, a 125 engine. TY!

JuanK is right. Beware of spending too much money on what is always going to be an underpowered engine. When I have bolted these kits on 50s they have still only been good for 40mph. Use what you have for the moment and keep your eye out for a replacement. As JuanK says the 125 is a completely different animal.

Original von diablo: The cheapest option for more power is a replacement engine.

Agreed, but i’m just thinking i could end up in the same situation or worse, at least i kind of know (well everyone else does) where i am at the moment.

no PK125xl crank with 75…
50 and 125 have different stroke. (43mm for the 50 and 51mm for the 125. Somebody please correct me if I am wrong with this number)

Yes Curare,43mm is right for a 50cc crank.

Novista,since you aready have the kit I suggest making the most of it.When I had my 50,best part of 20 years ago,I had no problems with the standard crank.We „tuned“ them with a DR102 and a main jet.The only problem we had was the kit siezing.

I put this down to young muppets throwing it together and non stop abuse.;D

Basically I say use what you have and look out for an ETS motor or a PK125XL motor to bolt in at a later date.My ETS is a little demon and I think the 125XL was basically the same motor but don’t hold me to that.

Good luck.