P150X engine swap

I have been monkeying around with my vespa p150x for some time now and after an engine rebuild a year ago it is now running so-so with a max speed of
83.5 kilo (downhill) lately it has been overheating after I ride it for more than about 10 minutes, I suspect this is due to a timing issue but havent been able to sort it out.
I had been considering fitting a 177kit and exhaust but wanted to straighten out the „issues“ with the stock engine first. Last week I saw a great deal on an internet auction and I bit. I picked up a rusted p200bme (elec. start) with a running engine, wasted body, and nice euro tail/headlights. I ended up trading an old polaroid camera for it, so it really only cost me the amount I spent on rental truck and highway fees to go and get the thing. So, my question is this. Is it reasonable for me to consider just swaping the p200 engine into the p150x thereby curing all the problems and ending up with a faster more reliable p150x. I am concerned about the fact that the p150x has points and in order to fit the electronic ignition of the p200 engine would I have to changeover the wiring harness too?? I suppose that another solution is to sell the p200 engine and buy a 177 kit and exhaust with that money. I have a p200 in the States and it runs great, I really like the p200 engine and want to plant it in the 150 but don`t want to willingly step into a nightmare. Any suggestions would be greatly appreciated
I am currently in the process of dismanteling the p200 for all of its usable parts- its really a mess.

thanks very much
Denkikun (banchou)

Copy this question onto the" Vespa classics" board you should get a good response from those in the know. Stick to that board its the most visited.