Power Struggle, 15mph MAX!

[MadzBiker1]

Alright, i've just had a 2nd hand carb off a working running bike same as mine, swapped the jets over because mine was larger to deal with the de-restriction / Arrow exhaust which the previous owner fitted.
I've put a brand new spark plug in aswell as i thought that might of been the cause.
My battery is in need of replacing aswell, but i didn't think the battery effected the performance of a bike when it's running, but i'm not sure so i'd appreciate it if you'd be able to give advice.

I have no clue now, i let my bike warm up for about 10 minutes and it idles at 2k nicely, on a cold start it's at 1.5k. When the bike is warmed up or cold it will not rev past 6.5k where beforehand it used to go past 12k. When riding, it struggles for power threw all the gears and in 1st it won't go past 6.5k, in 2nd it won't go past 5k etc... i've just had a new a chain & sprockets fitted, could that cause anything?!

I desperately need peoples advice?!

Cheers,
Ryan.

 

[gpzDave]

Oh dear, oh dear, oh dear... Aprilia is certainly living up to their reputation!

Well it could be that the carburettor isn't on 100% correctly, if their is even so much as a tiny gap between the carb and the airbox, or inlet, then it can cause all sorts of strange running problems. I doubt it has anything to do with the electrical system. A few questions, does the throttle work properly and feel normal? And is the choke mechanism working normally?

At least if it doesn't work properly again the bike could take up a new career as a doorstop

 

[MadzBiker1]

Oh dear, oh dear, oh dear... Aprilia is certainly living up to their reputation!

Well it could be that the carburettor isn't on 100% correctly, if their is even so much as a tiny gap between the carb and the airbox, or inlet, then it can cause all sorts of strange running problems. I doubt it has anything to do with the electrical system. A few questions, does the throttle work properly and feel normal? And is the choke mechanism working normally?

At least if it doesn't work properly again the bike could take up a new career as a doorstop

I'll double check over the carburettor & inlet in a minute.
The throttle is working properly and does feel normal at the moment & the choke opens and shuts but my bike never starts with it on lol. Exactly the same on both carbs.

 

[AZZ3R]

Had the same problem.

It will be either the carb/ choke cable or you have adjusted the idle switch on the carb.

What happens is, its restricting the amount of fuel or oil, you may be starving it of fuel or oil. When you open the throttle it starts to climb the rev range, instead it will just bog down and sit at a certian revs. Because it's not getting enough fuel or oil to keep going through the revs.

Put your bike on the side stand or paddock stand.

Start it up (N) and red line the bike (Max the revs) if it doesn't climb past say 6k and sounds like it's struggling to climb past it's not getting enough fuel.

If it cuts out before you get to your max revs it will be oil or air.

Because my bike is resticted when I redline the bike it starts to starv of air because it's carb restricted and it feels like it it's bogging down.

Could be an issue with the carb, When you say it's de-restriced do you mean it has a power valve fitted? because just putting a better exhaust on doesn't de-restrict it.

 

[MadzBiker1]

Could be an issue with the carb, When you say it's de-restriced do you mean it has a power valve fitted? because just putting a better exhaust on doesn't de-restrict it.[/quote]

Sadly i'm not sure about anything to do with power valves, i'm guessing it's deristricted as it goes over 60+ and is really fast off the line and goes to 12k+ rpms

 

[MadzBiker1]

Oh dear, oh dear, oh dear... Aprilia is certainly living up to their reputation!

Well it could be that the carburettor isn't on 100% correctly, if their is even so much as a tiny gap between the carb and the airbox, or inlet, then it can cause all sorts of strange running problems. I doubt it has anything to do with the electrical system. A few questions, does the throttle work properly and feel normal? And is the choke mechanism working normally?

At least if it doesn't work properly again the bike could take up a new career as a doorstop

Airflows fine, jets are fine, no blocks in the carb, brand new sparkplug, exhaust isn't blocked, head gaskets fine, piston & rings are fine, throttle cables right and the oil pump is at the right setting.
I now have no clue what so ever.
Any ideas? if not it's got to be a big garage bill again >.<
If not, then i will actually use it as a doorstop as you suggested at the moment with the mood i'm in with this bike lol.

 

[gpzDave]

When you open the throttle it starts to climb the rev range, instead it will just bog down and sit at a certian revs. Because it's not getting enough fuel or oil to keep going through the revs.

I agree with AZZ3R, it will likely be that the mixture is too lean at higher rpms.

I wouldn't be surprised if there was a small gap in between the carb and the engine OR there is a hairline split in the inlet tubing. Also, it doesn't help that the bike has been modified, it adds a lot of variables into the mix. If it was 100% stock then there would be less to worry about. Never mind though, I'm sure you'll get it sorted!

I hope so anyway, it is a bit of a shame to have a sportbike going everywhere at 15mph!

 

[Darkzy43]

mine had this problem wouldn't rev past 7k in anygear including neutral and no power.... my engines on the kitchen table with crank seals and crankshaft being replaced :/ ... sorry to say it lol.. but that may be the problem

 

[MadzBiker1]

mine had this problem wouldn't rev past 7k in anygear including neutral and no power.... my engines on the kitchen table with crank seals and crankshaft being replaced :/ ... sorry to say it lol.. but that may be the problem

Ahh it's painful isn't it, i'll check it out later today lol. I miss riding : (

 

[lauriejennifer]

If you've checked everything else, logic would say to check the bottom end.

mine had this problem wouldn't rev past 7k in anygear including neutral and no power.... my engines on the kitchen table with crank seals and crankshaft being replaced :/ ... sorry to say it lol.. but that may be the problem

Ahh it's painful isn't it, i'll check it out later today lol. I miss riding : (

And that's depressing.