ENGINE KEEPS CUTTING OUT

[TomosRS125]

Hi,
I would like to start by saying that i am new to this forum so hello.

I have an Aprilia RS125 2003, and it keeps cutting out as i am riding along. I have taken it to my local garage and they replaced the float valve as it was flooding a little and they also cleaned out the carb but this has not solved the problem.
The bike runs ok but when i open the throttle in 2nd and 3rd gears and go up near 7-8000rpm the throttle doesn't respond, the revs drop gradually and then the engine cuts out.

Can anyone offer any advise on what might be the cause please?

Tom
____________________
Aprilia RS 125 - My first step towards death

[russell210276]

hi and welcome first things first do a compression test on the engine.


try running the bike again again and when the engine starts to die open the choke a little at a time see if that cures the problem or makes it run better if it runs better with the choke on your running lean at the top end.

but could be a fuel problem maybe not filling the carb up quick enough.

what colour is the spark plug?

[TomosRS125]

Hi and thank you for the reply.

The bike got recovered back to the garage earlier so can't look at condition of the spark plug at the moment.

If it is running lean at top end how can this be solved? I am very mechanically minded but never worked an Aprilia before so sorry if i come across dumb but believe me i'm realy not.

Is it possible that the CDI mod has not been carried out as the bike is derestricted, would that cause it to cut out?

Thanks
____________________
Aprilia RS 125 - My first step towards death

[titan666]

Hi

places you could look

if its not allowing enough fuel to the carb then check along the fuel delivery (pipes/filter etc)i even cleaned my intank filter(should have two small cylinder filters attached to little pipes on the end of the tap that stick into the tank) but drain the tank first as you will have to drop the tap out of the tank..

air filter is it new?

if the garage had your carb apart im assuming they cleaned it so no point mentioning jets(keep that in mind too)

i replaced all my fuel line and inline filter and dropped the tap out aswell as removing the carb and cleaning the fuel tap itself and checking with a wire to make sure the feed holes were free(i was pretty anal )

be gentle if you clean the tank filters as they are delicate so dont fiddle just spray them off!

compression test is another good idea as already mentioned!

hopefully you get it sorted as mine was doing pretty similar stuff and when i cranked the throttle it would just pull back and start to die quickly!(even got to the point it wouldnt pull away!
____________________
love my susuki gz 125 maraurder 1998

[TomosRS125]

Thany for the reply Titan.
Ihave passed on the info you provided me with to the garage and they are going to check those for me.

They did suggest that it could be that it is not getting a spark as the revs wind up, does anyone know if that is a possible reason?

Also the garage say the battery keeps going flat (has never been going flat for me so don't know what they are doing to it) so is it possible that there is a bad earth somewhere and would that cause the engine to cut out the way it does?

Cheers
____________________
Aprilia RS 125 - My first step towards death

[DMCpro]

try running it with half choke, or full choke at high revs. check your reed valves - change your spark plug, if youve done all that, check for piston slack
____________________
Honda CB-1, TS125X
VW Golf Estate

[titan666]

wouldnt worry too much about the battery as mine went dead 3 times during repair and testing as it couldnt get a good long run and allow the system to charge the battery itself!


let us know the outcome:)
____________________
love my susuki gz 125 maraurder 1998

[TomosRS125]

ok cheers for the advise, i'll have all the bove mentioned things looked at and see if that solves the issue and let you know.

Does anyone know where they best place/cheapest placeis to get a new cylinder and piston kit?
____________________
Aprilia RS 125 - My first step towards death

[TomosRS125]

****UPDATE****

The garage have just called to say they can not find anything wrong with the bike and that they have taken it out for a 10k run and it hasn't missed a beat.

So is it the way i am riding it that is causing the problem??
What sort of revs should be staying above when i riding it? As if i am not keeping the revs high enough when riding around town would this cause it flood the carb or something like that?
Any advise is much aprreciated guys.

Thanks in advance
____________________
Aprilia RS 125 - My first step towards death

[DMCpro]

keep above 4k when driving i find if u let clutch out too fast at low revs it just bogs
____________________
Honda CB-1, TS125X
VW Golf Estate

[P.]

The RS is made to be revved.

Mine only sat around 1500rpm at traffic lights, everywhere else was above 6k when possible.

Next time it stops dead, unbolt the tank, flip it up and take out the spark plug. Check the colour. Black and coked up, rev it loads more. White, cry and get the issue fixed quick

I liked mine, but it broke down often...

[TomosRS125]

yeah i do that loads of the lights and look like a right knob, lmao
____________________
Aprilia RS 125 - My first step towards death

[P.]

[TomosRS125]

OK, revving at the lights and revving under load, 2 different things...[/quote]

I did mean whilst trying to accelerate off the lights and not revving it enough it would bog down and it makes you look stupid.

I just got the bike back and i must admit it does seem ok. i think i wasn't keeping the revs high enough, but now i am trying to keep the revs above 5k where possible things seem to be a lot better.

I'm going to change the spark plug in a bit so i'll have a look what the old one looks like.

Really want to get to know my way around my bike instead of taking it to the garage as doing my own repairs is so satisfying.

Thanks for all the replies and suggestions guys, you've been a great help.
____________________
Aprilia RS 125 - My first step towards death

[Aff]

[P.]

Yeah Aff, cheers for that

Find out what plug you have currently.

A derestricted RS (One that indicates 100, has power valve and servo fitted, exhaust etc) needs a BR10ES.

A standard one needs a BR8ES.

I ran mine on a 10 all the time aside from running in, which I used an 8 for.

[TomosRS125]

I have bought an BR10EG, is that different from a BR10ES (obviously its different can the BR10EG still be used)?
Don't know what is it there at the moment though.
____________________
Aprilia RS 125 - My first step towards death

[P.]

[TomosRS125]

I'm new to the Motorbike scene, so how would i know if it was FULLY derestricted?
____________________
Aprilia RS 125 - My first step towards death

[Alpha-9]

[TomosRS125]

It does WELL over 80 so i already knew it was derestricted, it was just the FULLY derestricted bit that got me thinking?
____________________
Aprilia RS 125 - My first step towards death

[P.]

Check the CDI for being modded.
Different exhaust? Not just the end can but full system.
Lift up tank, to the right should be a power valve servo and a cable running to the power valve fitting to the top side of the engine.

Thats derestricted and "should" indicate about 100mph at full chat.

[TomosRS125]

It does do around 100 so i think all the above must have been done although i will check.
Where do i find the CDI unit?
____________________
Aprilia RS 125 - My first step towards death

[cornish]

Is it possibly some weirdy electrical problem? How long after cutting out will the bike restart?

I had a similar thing with my GT years ago. Everyday it'd cut out at about the same place on my way to work. I'd sit and have a (uneducated) look at all the obvious bits, by which time when i tried it again it'd start up and run like a dream.

I picked people's brains and checked all sorts and bribed people who knew what they were doing with cake to have a look at it for me. It always ran flawlessly for everyone, then cut out as soon as i was riding it home Ditto when i took it to the garage

Eventually one morning when it cut out i rang the breakdown so someone else would be having a look at it to see what was up. When the van arrived it started beautifully and ran lovely

I tried a mobile mechanic recommended to me by someone and he eventually diagnosed a snap in one of the wires round the little coil thingies. What was apparently happening was as the bike was running and warming up the coil expanded and pulled the snapped bit apart at which point it cut out. Once it had cooled and shrunk back it'd start and run fine again.

It was all beyond me as in my girlie head if the whole coil was made of copper surely current would go round it any old how as it all conducts??? But i find it best not to question things like that as it causes smart bikey people to look at me like i'm bound to find things confusing if i stray out of the kitchen. . . .
____________________
smile and be happy. . . .it gets right on everyone's tits!

[TomosRS125]

***update***
My bike now runs fine so guess its previous owner hadn't looked after it very well, as I cleaned out the carb, changed the spark plug and fiddled with the idle valve and it's hasn't cut out since so happy days.

However, I wanted to know how fast the bike will go so took it out and no matter what I did I couldn't get it to go over 85mph but I thought unrestricted ones are meant to go 100, so any suggestions guys?

Cheers for all your previous help and cheers for any further advice in advance
____________________
Aprilia RS 125 - My first step towards death