Aprilia not working and making weard noises

Gears · Renault 5 Driver Joined: 01 Jan 2006 Karma :

Right i have an aprilia rs125 2000, everythings been running fine on it up untill now.
Whenever i start the bike i always warm it up to 60 degrees or whatever its measured it, i dont often go on massive blasts at high speed on it but 2 days ago when i finished work i got on the bike and it started fine, i warmed it up get everything ready and pulled off as i go onto the road the throttle stuck and the bike was running at high revs and i really had to twist the throttle hard to unstick it, anyway after that i got home all was fine with it, now yesterday i came to get on the bike and when i started the engine it wouldnt work unless i gave it allot of gas got the engine going and the aprilia manual sais dont rev it over more than 4k revs when warming up so i eases off the throttle gently but when the bike hit 6k revs it cut out, i gave it a few more goes and it still did the same but on the last time i heard a loudish bang so i called it a day and got the bus instead.
I tryed it again today and its still doing the same but before it cuts out it makes a loud bang noise but i cant work out where it is coming from.
Does anyone have an idea of what it might be?

Ride Safe
Gears

Kickstart · The Oracle Joined: 04 Feb 2002 Karma :

Hi

That it starts suggests that it is fairly healthy (ie, getting a spark, some fuel and has compression). Probably worth taking the plug out and giving it a clean, checkin the air filter and checking that the bike is not flooding while parked (turn the petrol off while parked and see if that fixes the problem).

One problem I have had once with an RS125 was the gap from the ignition pickup to the flywheel. Cannot remember what it should be (will check the manual tonight) but they are often too wide and will then cut out at low revs (but tend to be OK at high revs).

The bang is probably unburnt fuel in the exhaust igniting.

All the best

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

Gazdaman · I did a trackday!!! Joined: 12 Aug 2004 Karma :

bang on, the bang you're hearing is just unburnt fuel in the exhaust lighting.

I rekon it's probably just a fouled spark plug.

Gaz

dransy · World Chat Champion Joined: 04 May 2005 Karma :

Mine is also doing this every morning , starts up cuts out and makes a pop noise. As far as im aware its just the plug?
____________________
Being shot out of a cannon will always be better than being squeezed out of a tube. That is why God made fast motorcycles

UpYourNose · L Plate Warrior Joined: 09 Jan 2006 Karma :

I have NO experience with 2-stroke in general or 125RS specific, but since it DOES run in high revs, but not in low revs, is it possible the slow jet in your carb is faulty? (clogged, fallen out, whatever)

Gears · Renault 5 Driver Joined: 01 Jan 2006 Karma :

Hmm ive tryed the spark plug and cleaned out the air filter and the problem still occurs, i have a mechanic picking it up tuesday now, so when he checks it out ill post on there what the diagnosis is.
Thanks for the help anyway.

Ride Safe

MADDOG · Borekit Bruiser Joined: 26 Jan 2005 Karma :

had exactly the same problem when i had my rs all i did was remove the slide from the carb give it a blow check for dust and relocate it back in. there is a groove on the front side of the slide which should slide round a track type part on the front body of the carb just make sure its all located properly and that should sort it. it did for me
____________________
Aprilia RS125 Harada. has gone now have a SV650s K5
Are you meant to scrape knee slides or rip them clean off?