shoddy revs past 8k (00 rs125)

[Akiraprise]

Hey, I've just brought a mint condition RS125 2000 with custom graphics etc (looks really sweet) for 650 quid, is this a good price by the way? got new tyres, sprockets, pads etc and is on 16k.

EDIT:
Basically, the previous owner said that once the bike reaches AROUND 8000rpm the bike becomes *shuddery* - is this a problem with the powerband or even spark plug (any other reccomendations?),I hope this will be cheap to fix - as allways lol.

The only other problem with it is it needs a new battery - can i order these off of ebay or not?


cheers for reading, i'll be getting the bike in a week and will have plenty of pictures.

[Beef]

this could be a problem with the plug, for the sake of a few quid u might aswell pop a new one in, if this doesnt fix the problem it might b time for a decoke (remove any carbon from inside the cylinder) and also check that the power valve is working correctly, iv seen the power valves stick on these due to too muck carbon,

oh and yes that is a good price

[Kickstart]

Hi

Sounds like a very good price.

8000rpm is where the power valve should open. Possible if the battery is shot that it is failing to open (although I would suspect it would have enough power from the charging system).

New plug is well worth it. You will probably be fitting a new one every few weeks anyway.

However worth checking over in detail. Do a compression check (Colin Walls RS had 145psi compression yesterday). Clean the fuel filter out. Clean the power valve (and check it is the right way up). Etc.

All the best

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

[Akiraprise]

thanks kickstart.

I'll have to rule the first one out as the lights etc work fine - so the battery as power...

A plug will be the first thing i change - any difference between standard and irridium tho?

as soon as i get it round my place i will be cleaning out all of the gunk out of the system -it's been sitting for 2 months and replace all fluid etc.

he said that the engine, at 8k the revs wouldnt rev any higher, unless he pinned the throttle back and there;d be a sudden rush of power, ie sounds like the powervalve isn't opening properly, maybe it's coked up with crap and just needs a good clean? I HOPE!

Also, it wont start,we tried bump starting it, and it made the noise of it trying to bumpstart, now the fuels' really low - this shouldn't be it though, i'm not sure the engine was getting a spark, as the electrics are a little faulty, so hopefully that'll fix it and a new plug, i also intend to clean the carb out and replace all fluids as they have been left for 2 motnsh

thank yuo

[Biker-Kev]

If it wont start check you have not flicked the kill switch.

Also where the throttle meets the light switch compartment on the handlebar, if you take this off you will find there is two positions for the throttle cable. Maybe it has been put in the wrong position.

Kev
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Zhongyu ZY50, Aprilia SR50, Motorhispania RX50, Aprilia RS125, Honda VFR400 nc24 and my corsa
https://www.bikepics.com/members/bikerkev/
Theory: Passed 8/11/2005 Practical: Passed 13/12/2005 Proud holder of A2 license

[Kickstart]

Hi

Iridium plugs are meant to help a touch, but to be honest they cost twice as much and will last no longer so until you actually get the bike running properly it is not worth thinking about.

Could well be the power valve is stuck closed (happens easily if used at low speed for too long), but normally they will still rev out like this (just stuff all power over 8000rpm or so).

All the best

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

[muddycoffee]

It would be worth checking the plug cap (not gap cap! ). Sometimes the original ones are a bit poor and if a crack develops or it's a poor connection to the HT lead you might get a little arching at higher revs.
Years ago we used to change our HT leads for silicon ones as they lasted longer, and were better.
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Suzuki SV650 naked Blue curvy with Givi Screen and G force can.