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Discussion Starter · #25 ·
So the new genuine Aprilia airfilter did not make any difference. I tried both 150 and 140 main jet, again the engine wouldnt rev past 6000rpm.

I took the engine out to see if there's anything wrong with the barrel or piston.

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Discussion Starter · #26 ·
Turns out I think I used the wrong gasket. I measured the squish and it seems to be greater than 1,4mm, wich is ofcourse too much.

Could this cause for the poor running I'm experiencing?

I believe the squish of my bike should be between 0,7 and 0,9mm. Is that right?
 

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I have 2 mm squish thickest gasket and half mm off the head ...

I read somewhere you want about 1.1 ? And lower that 0.8 ruins the bottom end
 

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Head off
A coil of solder or a few then a few dabs on grease on the piston crown by the bore put the solder wrap in the grease head on and turn the engine over at the fly wheel by hand then head off measure the depth of the solder and take an average ...
 

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Unless it's sucking air gasket won't be the trouble if it's struggling to rev then the plug has had it or it's a tad rich ... that's assuming the rave valves working
 

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Thats what I did too, exept for the grease.

However, as I took the barrel off I found a small strip of aluminium between the right hand side carter and the crank.. It's about 3cm long, 5mm wide and 1mm thick. o.0

Where the F did this came from?
 

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125cc Sportsbikes Boffin
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Hi

Also vote that the gasket isn't the problem. That is probably within spec of a standard engine.

If the power valve isn't opening then it will still go beyond 8k, just be producing little useful power over that and so really struggle over 8k in anything other than the lower gears.

Personally check the ignition and the ignition timing.

All the best

Keith
 

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Thanks for the feedback all.

I've been struggeling with this for quite some time now and haven't made any progress. Therefor i've made an appointment with a tuner who will take a look at the bike for me. I'll let you guys know what the diagnosis is.
 
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