rs 125 problem

[dave_225]

hi all nice to meet u,I have A problemwith a 2000 aprillia rs 125. the bike started reving by itself after around 30 seconds of idle goes to around 6k revs.

it started doing this then cuts out like bogged down when trying to pull away in gear changed the plug and tried adjusting the idle screw this makes no difference try loosing throttle cable but this also makes no difference any help appreciated i only got the bike the other week and i dont know much about 2 strokes.anything else i can try also clutch bites right at the end of lever whch is awkwar have adjusted cable on side but that only brought it in a few mm anyway can get it to bit closer so not stretching my fingers as far as can as when turning its a nightmare

[Kickstart]

Hi

The revs issue sounds like an air leak. Possibly a cracked carb rubber (ie, the rubber block between the carb and the engine), possibly worn crank seals (although I wouldn't expect it to rev that high if they were just worn), possibly a leak elsewhere.

As to the clutch cable, the first and main place to adjust it is on the left of the engine. Once that is correct adjust it at the lever.

All the best

Keith
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[dave_225]

hi there,
well have just had it running revs fine with tank upand bike lean on stand however drop tank straighten up go to pull off.pull throttle back bike seems to bog down there is no power then engine dies just wont rev any ideas,

revs seem to not stick as much were moving quite freeley with bike on side stand. its idling now at about 1800.but adjustment on side of carb is doing nothing.

thanks in advance

[Kickstart]

Hi

May seem like a silly question, but is there enough petrol in the bike? Often the revs climb (but with a complete inability to take any extra throttle) as the petrol runs out.

Which screw on the carb are you using to adjust things? There are 2, one does the idle speed and the other the idle mixture.

All the best

Keith
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[dave_225]

the big black one which i was told is idle speed? ,petrol wise its full basically i was out the other night but occasinally at junctions bike was boogin down like now where it wont pull away but hadnt been run a while so figure be ok,then revs started climbing by themselves on idle to around 6k ish i noticed yesterday throttke cable was trapped by battery seemed to solve idle problem some what but now its just dying when try pull away but will rev freely when on side stand in neutral.

[Kickstart]

Hi

The big black knob is the idle speed. All it does is push on an angled bit of the carb slide as you screw it in, lifting up the slide.

To me the bogging down as you try and move off sounds like it is a bit lean at low revs / just as you open the throttle.

I would reset everything back to stock (check the idle mixture screw), and make sure everything is clean (might well be worth draining the tank and carb, and checking for water in the petrol).

All the best

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

[dave_225]

yeh just as you try to pull of mate,I have no idea how to set everything back to stock.I dont know much about engines just what ive read on the net atm.

the bike seems to start a bit hit and miss once its cut out but if you knock it off with the kill switch it will start no messing next go

[tutton]

Sounds like multiple issues, id say airleak too with the manic revving, apart from that id whip the plug out and post us a picture of its condition as 2strokes regularlly kill plugs, and if thats coked right up it will likely start but not ignite properly when trying to pull off..
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Past: '05 Peugeot XPS '99 Aprillia RS125 '94 FZR600R
Current: '02 ZX636 A1P '51 CCM R30

[dave_225]

its a new plug mate got it yesterday (br10eg) idle problem seems to have gone now but i think its idling off the throttle cable as adjusting the carbs makes no odds.but if u slacken the throttle cable it will cut out,it will pull of with the choke on but as soon as u put it off the and bikes in gear it dies just nothing when u rev

[Kickstart]

[tutton]

Next step is to do what keith has suggested, get the carb open and set back to original settings.
I have a brand new rs125 haynes manual you might be intrested in
____________________
Past: '05 Peugeot XPS '99 Aprillia RS125 '94 FZR600R
Current: '02 ZX636 A1P '51 CCM R30

[dave_225]

i have only adjusted the idlespeed which made no odds should i adjust the screw to the right pressume thats mixture??

no kinks in pipes throttle appears to move freely revs nice in neutral really free and easy just when u stick in gear it either cuts out instanlty or when u try pull away had nothing on throttle and just dies

[dave_225]

my bad if left on tickover it will cut out after say 2 mins then struggle to start again

[Kickstart]

[dave_225]

bike is 2000 plate harada fullpower version.

[dave_225]

i cannot find fuel filter pipe comes off tank and straight into carb next to idle mix screw?????

[Kickstart]

Hi

Which carb do you have?

On the phbh carb (fitted to most RS125s, certainly new for the last decade or so until the latest version) the pipe goes onto the carb on a banjo shaped bit with a bolt through the middle of it. Turn the petrol off and remove the bolt and then take the cover off and you should find the filter which is a mesh disk.

On the VHSB carbs (fitted to older RS125s, often fitted as an upgrade to newer ones) the filter is a mesh tube that goes in where there is a bolt just under the pipe the fuel goes into.

All the best

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

[dave_225]

ok atm got tank off side fairing and airbox there is no filter in the air box? do i need one?
fuel i will check feulfilter now,bike seems to be starting fine always now just when u put in gear its reallybogged down like when u trap a still saw in brickwork and it bublles but does nothing .if that makes sense then dies.like no fuel

[Kickstart]

Hi

Should have an airfilter. Lack of one does affect the mixture, and also will allow dirt into the engine (and potentially one grain of sand could do a lot of damage).

All the best

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

[dave_225]

i wil get one now,also the two pipes of the fueltank not the actually one that goes to the carb where is best place to route these as there all mangled up up not really going anywhere.

[dave_225]

could you recommend a good air filter to get please?

[Kickstart]

[dave_225]

checked fuel filter bit of rubish on it so cleaned off replaced air box but bike will not start??

[Kickstart]

[dave_225]

yeh petrol on mate. its started hammering it down so i have covered up and come back in.i blew down the hose off the fuel filter no shit came out just air.fuel cominf from tank ok as turned it on and seemed to be coming out ok other 2 pipes one dribble about a egg cup of petrol out the other nothing/