ENGINE SWOP

[rosiesdad]

Hello all just found this site seems very useful I have a question if anyone can help I have a 1964 V90 the scooter has been fitted with a PK100S engine and changed to 12v electronic ignition. I have no got hold of a 100 SPORT with 135 DR kit to swop the engines over will I need anything from the PK engine

[Juan]

2 ways to go about it.

If the PK motor runs well then just swop over the top end, I can't remember for definate but I think the Sport crank was slightly longer duration so it could be worth changing that over.

The second way is to put the flywheel and stator from the PK onto the Sport motor but if memory serves the Sport is a 3 speed 'box which you really don't want.

[jonnysnatchsniffer]

as juan says you will be better of putting the dr kit on the pk cases, i put a polini kit on a 3 speed 90 and it was shit

[rosiesdad]

Thanks for the replies I have a problem then in the fact my PK engine is also a 3 speed is it easy enough to change over the gears from a 4 speed engine.

Also I have heard or read that pre 65 V range scoots cannot take kitted engines very well due to space issue I know it is very tight in there with the PK enigine and the DR head is much larger than is there now

[Juan]

Re-reading I see a problem.

The first series of PK 100 was infact just a rebodied V100 hence the 3 speed and your need to convert it to 12v electronic, it'd slipped my mind.

I'm not 100% sure on the early chassis but as far as I know the only real difference was the engine door was smaller.I'm sure someone else will put me right if there is more to it than that.

The early engine cases couldn't be kitted, or at least not without fairly heavy modification.

A 4 speed box is pretty much a straight swop over on the PK or Sport cases.

[jonnysnatchsniffer]

yeah i think the crankcase mouth is smaller so the spigot of a new kit wouldnt fit in there on the early models, even if you have the small door everything still fits in ther its just harder to get to the spark plug