2001 prebug complete rebuild

[coltc7]

Hello there !! I'm gonna start ordering stuff to rebuild a prebug ... Found that old girl for 250$ ( canadian ) soo probably 5$ US hahah !! 





It was own by a 16 old boy ... he said that he change the cylinder ... but probably leaking somewhere cause she was sooooo dirty !! Not a single srew wasnt strip or was matching another one !! Brake switch have been bypass so it cause all the wire to melt !! 

Anyway everything have been repair and she's running good now ... i'm gonna strip it down completely this next winter and try to make it brand new again !! Found another one without registration so i can begin working on motor . 

I want something reliable ... not a speed machine ... i'm a photographer so its gonna be use around town and a bit of off road to reach some nice locations . 

Only thing i know for now ... polini corsa ... cylinder its gonna be !!! 

Wich crank would be a nice match ??... polymer bearings or not ?? Exhaust ?? Carb?? 

Would like to go bigger for the wheels (more tire option) ... but for what i have read ... only aerox wheels are a direct fit and they look rare as shit !! 

Oh and by the way ... if someone have the front rack collecting dust somewhere ... i'm a taker ... your price is mine !! 


Sorry for the bad english ... i'm french canadian ... so my phrase syntax maybe a bit weird to you !! 

[geoffh]

Don't,t worry about the language I,m English but you wouldn't recognise my version of it.There are quite a few build threads that you can read up on but but dexameth is building a zumu at Parts for Scooters which is shaping up to be a great street scoot at affordable £££ he,s gone for a sports exhaust which is to loud for my taste I prefer a stealth exhaust technigas silent pro or malossi wild lion will keep the CRMP off your back.

Geoff

[coltc7]

Thanks!!

Think ive read all the prebug thread since i'm in the forum haha ... sooo much information from great people !! But most people are going for speed build !!

I want to build something with nice torq that dont need to run 15k !!

Ive found some dyno sheet from a lots of exhaust .. but nothing on cylinder kit that can tell the sweet spot rpm .

[Zino]

If you only were going to do one thing .
Swap in a cast iron 70cc bbk kit for reliability and power from top to bottom
Malossi ,Polini ,Top Perfomance trophy ,Naraku are great examples .
You may need to upjet stock carb 5-10% to keep engine cool .

Next Add pipe
2 choices Loud and abnoxious expansion pipe You will get the Best Top Speed . Yasuni R Tecnigas Next R are good examples
But these will require a bunch of cvt tuning to match the narrow power band of the pipe .
Lighter weights and stiffer clutch springs .
A stealthy street pipe very little cvt tuning needing not much louder in stock .
Really helps take off and adds a couple miles Top Speed .
Malossi Wild Lion and Stage 6 Street pipe are good examples

When you add a pipe you need to up jet the carb or Replace for a bigger carb.

Carb Upgrade
a 17.5 or 19 mm dellorto is a easy swap replacing the stock dellorto

Gears
Add 15/50 gears or 43 /14 gears to give you even more Top end you will need to reset the transmision for these so you still have wheelie power.
After You just spent about 800 Bucks you are mid 50mph  or better




A Sport variator for better shifting and a little higher top end .

[Zino]

You are on the right track think about where you want to end up and work backwards .

Sport bbk kits
Malossi ,Athena,Polini,Top Performnace Trophy ,Stage 6
Rpm Ranges typically for powerbands are mid 7's to mid 9's for rpms which is about 1000 rpms over stock
They are all very crank friendly by maxing out below 10 k rpms.

Mid Race
Powerbands live over 10 k rpms and really beg for a Crank upgrade

[Zino]

Here is a article that will help you match pipes carbs and BBk's for best performance.
www.tuningmatters.com/how-tos/advanced-knowledge/50cc-scooter-tuning-guide/

[aeroxbud]

Great scooter to build up. They are quite light so go well, even just fitting a good exhaust.
The vertical Minarelli is a solid engine. I have the same one in my slider.

[coltc7]

Thanks Zino for the link !!

Thats exactly what i was looking for ... crank is gonna be the first upgrade ... im gonna split the case for a deep clean and a powder coat paint so ... why not change it !!

Have to decide which one ... too much choice again !!

Have been watching some YouTube vid from scooter swap shop ... thats why im sold on the corsa !! Their wheelie zuma is paired with a corsa and a malossi crank ... looks like a nice wedding !!

[Zino]

If your going with new crank the Corsa and Yasuni r or better yet Yasuni C16 is a very powerful set up.
The r would push to 11k the C16 is going beyond 11k with the corsa

The corsa and the stage 6 mk2 are in the same mid race class so you can use the dyno curves as a rough guideline

www.pedparts.co.uk/blog/sports-exhaust-testing-50cc-and-70cc-sports-mopeds-part-one
www.pedparts.co.uk/blog/choosing-a-yasuni-exhaust-for-a-sports-70cc-kit


These PreBugs are light weight can go become absolute rockets
Checkout Pigs Build
49ccscoot.proboards.com/thread/17391/pigs-65mph-2002-70cc-prebug

How fast you go all depends on how much you spnd and how well you tune .