Aprilia RS125 Problem?

[leepick]

hi, last night my aprilia backfired and now wont start, i fitted a new teflon coated mitaka piston but didnt replace the power valve which is obviously faulty because before it backfired i revved the bike past 8k revs (which is when the valve comes into play) and thats when it happened. ive taken the valve out and taken the barrell off and checked the piston and everythings fine, but when i press the electric start with the plug in it fails to spin fast enough to start, but when i take the spark plug out it moves freely but still pretty slow.

im wondering is this because my battery doesnt have enough power and i need to purchase a new one?
before this happened the bike was running perfectly, so the powervalve has caused me a problem but thats removed now.

need help asap please thanks.
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Aprilia RS125

[leepick]

just checked battery voltage on the on screen display and it says theres 10.9 volts but drops to 9 volts and even 8 volts when i press the electric start... im certain its the battery i just want a second opinion. thanks
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Aprilia RS125

[leepick]

sorry battery sits at 12.3 volts but if i turn the lights on or try to start it the power drops to 9 volts and under
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Aprilia RS125

[P.]

battery should be showing a good 12.8+ when its sitting there off.

Try charging it first! Bump start the bike?

A power valve could be jammed, maybe strip it and clean it, check all connections.

[leepick]

[P.]

My RS ran without a battery... so I doubt its that.

[leepick]

[Frost]

It'll bump start without a battery in it. So bump it to get it running and take it for a nice long ride to charge the battery up a bit. IF the battery stays flat even after a ride then it's useless, or possibly the charging curcuit is faulty / not connected properly.

If the bike won't bump start it's either flooded, fouled the plug, carb isn't sat on properly etc etc.

[leepick]

[P.]

If it wont spin fast enough, its definitely the battery.

Yea, bumping a 2 stroke every day is no issue Bumping the Daytona 600 in the wet wanting to get home... now thats exciting

[Frost]

Bumping an IL4 is for girls, bump starting a flooded 600 single is for men

[leepick]

bumping a 600 in the rain must have been fun lol

and yeh battery must be shagged. took the powervalve out anyway im not risking blowin another piston
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Aprilia RS125

[P.]

[leepick]

[leepick]

[P.]

Cover the hole, with the blanking plate for the RS engine.

Also, might need to change spark plug again as you arent using the derestricted RS anymore

The GT125...

More reliable than the RS after its been treated bad

Was alright, mine had sv650 filter, modded air box, straight pipes, scorpion can and rejetted carbs, took 2 of us down a hill at an indicated 92mph GPS was only showing 80/81 and we did have oversized tyres

Great bike, handled ok for a 125, bit heavy but i'd have one again.

[leepick]

[leepick]

[P.]

Battery does sound shagged.

Its by no means slow by the way, doesn't have the immense kick of a two stroke...but definitely will run happily.

70mph on a 4 stroke 125...does happen...shame some bikes just cant manage it, my 125 cant

[leepick]

[P.]

Might as well but the GT125, the YZF is a definite waste of cash, uncomfortable and slow. Much preferred the GT125.

As much as this is always said, just use the £££ to pass your test and get a more powerful bike.. no worries

Used GT125R...anything from £800 to £2500 really... Aim for a 07+ reg.

[leepick]