I want to overbore my barrel to 70 or 80 cc.Aprilia rs50

Theoutsider · Scooby Slapper Joined: 03 Sep 2008 Karma :

I am interesting in overbore my barrel.How much does it cost,do they give you the piston,rings and all the stuff?They overbore the cylinder head?Where can I find a garage in cambridgeshire.Maybe in Peterborough.

Kickstart · The Oracle Joined: 04 Feb 2002 Karma :

Hi

Easiest solution is a replacement big bore barrel with piston. Probably cheaper than a piston, rebore and gaskets.

All the best

Keith
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Rockhopper · Trackday Trickster Joined: 18 Jun 2006 Karma :

Are they a plated bore anyhow?

5v3d3b0 · World Chat Champion Joined: 24 Sep 2006 Karma :

How much you willing to spend?
There are some 74 cc kits that will get you a real kick if you want to lash out some cash. You should essentially get an exhaust and upjet/carb as well

Kickstart · The Oracle Joined: 04 Feb 2002 Karma :

Theoutsider · Scooby Slapper Joined: 03 Sep 2008 Karma :

Ok I found a great Bargain,A complete engine with a 90 cc kit,racing gearbox,it has 0 miles.I already got an 28 mm carb,metrakit exhaust,it did 64 mph ,I`m wondering how fast it will go with the new engine.Oh btw 190 quid for the engine

chillpill · World Chat Champion Joined: 12 Aug 2008 Karma :

it didnt do 64 , on the clocks yeah , but just no Wink

190 quid for the engine is a bargin , defentley buy that , its so good ahving a spare engine , youll have loads of spares wich is very usefull if you own a 2 stroke 50

could be looking at around 70 mph top pushing it , dependidng on what bore kit it is , and also the gearing will have to be fiddled with

28mm on a standard 50 bore , are you mental Shocked

skinny · Nitrous Nuisance Joined: 16 Jul 2007 Karma :

Kickstart · The Oracle Joined: 04 Feb 2002 Karma :

skinny · Nitrous Nuisance Joined: 16 Jul 2007 Karma :

My bad miss read it please accept my humble apologies chillpill Very Happy

28mm on a standard 50 bore , are you mental Wink

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Ste · Not Work Safe Joined: 01 Sep 2002 Karma :

SoND · World Chat Champion Joined: 10 Jul 2005 Karma :

Racing gearbox?
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Go back to bed - You have no rights - "Streetfighters ~ Mainstream motorcycling's crackwhore sister."

twotakt · World Chat Champion Joined: 25 Oct 2007 Karma :

I'd be wary about buying a second hand motor which claims to be working without actually seeing it working/testing it.

90cc bore can put alot of stress on the bottom end of the motor and iirc you'll have to machine you cases for it to work. Whatever the case, its not really pratical if you rely on the bike to get you about. You're best of going for 70-80cc with a 19-21mm carb (dellorto phbg) and a nice exhaust system to match. These things will give you the best price paid:power gains ratio IMHO.

There's a lot of knowledge on the Aprilia forum in relation to the rs50, they should be able to advise you specifically on what setup to go for:

https://www.apriliaforum.com/forums/forumdisplay.php?f=21

Ta,
Jack
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R.I.P. Tareree Shiimi, 1985-2008

Theoutsider · Scooby Slapper Joined: 03 Sep 2008 Karma :

I know that it sounds crazy 28 mm carb on a 50 cc,but i`ve bought my bike with that carb,so no reason to change it.Btw it has 0 miles from the rebuild,the engine is working,all the bearings are alright.I forgot the name for the gearbox.when i bought the bike it did 75 mph,but after i changed the cylinder i wasn`t able to reach even 67 mph.

Theoutsider · Scooby Slapper Joined: 03 Sep 2008 Karma :

the exhaust is pretty good,Metrakit Oval,the carb is Dellorto i forgot which model.But still i need to change the airfilter.I try to find the standard airbox but nobody has it.

Hutchysrs50 · World Chat Champion Joined: 15 Sep 2008 Karma :

Hutchysrs50 · World Chat Champion Joined: 15 Sep 2008 Karma :

ms51ves3 · Super Spammer Joined: 08 Jun 2007 Karma :

Theoutsider · Scooby Slapper Joined: 03 Sep 2008 Karma :

I`m 17 but i haven`t got enough funds to buy a rs125.So thats it for the moment

chillpill · World Chat Champion Joined: 12 Aug 2008 Karma :

Kickstart · The Oracle Joined: 04 Feb 2002 Karma :

Hi

YSR50 uses a pretty small carb as standard. There are oversize carb kits available, but nothing like 28mm kit. 24mm flat slide Mikuni kit is the biggest I know of.

But there is a video of a YSR50 on Youtube, which has had a CR500 engine fitted.

All the best

Keith
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Traxpics, track day and racing photographs - Bimota Forum - Bike performance / thrust graphs for choosing gearing

ms51ves3 · Super Spammer Joined: 08 Jun 2007 Karma :

MADDMAN · Two Stroke Sniffer Joined: 18 Jun 2007 Karma :

hi mate... dont do it... dont tune 50's when i was 16 i blew all my money on my little derbi gpr50 (which is the am6 engine like the rs yeah?) i had metrakit 70cc bore, 21mm carb, metrakit sp undersling racing exhaust, cant remember what crank now, nice shiny one lol, better clutch metrakit foam filter. everything i could get my hands on basically... and yeah when it was working it was a little beast, but unreliable is not even the word for this bike... think i went through 2 bottom ends and countless topends untill all my money i had saved up was gone and now im left with nothing lol...

ne way you probably wont listen to me, i know i didnt when people were telling me not to do all that stuff to my 50 lol.. save your cash save up get your test done when ur 17 and buy a nice little 400 or summin

_nah_
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Current Bikes: Kawasaki zx6 g2 (my everyday transport), vfr400 project, honda crf250 (currentely with smashed crank cases) projects: 720cc 2stroke jetski engine, mini moto engined push bike Razz