View Full Version : RS125 2004 - can anyone help!!!

03-16-2009, 12:34 PM
Hi there,

I wonder if anyone can help.
Heres the story.
I bought an RS125 that i knew not a lot about (yes i know, stop laughing) anyway i got it nice and cheap so i thought, 'i'm pretty handy with a spanner, how hard can it be' well all was going well.
I had removed the crap out of the fuel tank and taken off and cleaned out the carb, i took off the cylinder head, piston, rings, rad the lot, replaced everything that needed replacing, measured bore/ring gaps/piston diameter etc all ok. So with new gaskets and new fluids i put it all back together.
Moment of truth, YES, Runs, sat there idling for 10 to 15 mins, warmed up nicely and i was a happy bunny.
So put it away thinking i had fixed something!!!!
Went out to show my mate 4 days later and it wont go (@#?#"$!!!)
Anyone have any ideas?
I've checked for spark, all good, there's definatly fuel going in (although i dont know how much) and i can only assume that mechanically it is ok, because it ran.
But heres the problem i have, how can i tell if my carb is knackered? is there anyway of checking its function off the bike?
I dont know if its been re-jetted or adjusted or anything?

Please, any input would be gratefully recieved as the weather is getting nice and ive got a bike that dont run!!!!!

Many thanks


Micah / AF1 Racing
03-16-2009, 12:59 PM
Probably just a fueling issue, RS's seem to hate starting after sitting for a while, a push start will normally do the trick as long as the engine is not flooded with fuel that has escaped the carb while sitting. A fresh spark plug might help too, if yours is coming out wet after cranking for a bit.

03-17-2009, 11:52 AM
nice one, thanks, i'll give it a go