Most of the noise from mine is the noise of the combustion explosion emanating from the cc and going up and out. I tried silicone blocks....didn't help much....if the head was thicker, it would be quieter.
How do those turned custom round heads sound? I gotta get me one of them.
Hi Pablo, it sounds like you have less piston-slap than mine. I could hardly hear my exhaust before.
Now:-
I don't tend to exaggerate and this is no exception.
I did both mods,
very thin corrugated cardboard inside the clutch cover, adhered with RTV silicon, then I put extra beads of silicon over the top, to stop the cardboard resonating.
I have a length of 1/8" rubber strip here, so I cut (roughly) 20mm x 8mm pieces, then folded each in half and jammed it between the fins, aiming for the points where the fins protruded furthest.
The difference has to be heard to be believed. The best, cheapest, quickest mod I've done so far.
I had a problem with clearance of the 3 clutch locator pins, so I cut a washer shape out of the cardboard to allow clearance. Two cuts with a sharp blade and it peeled right out.
(The cardboard I used was extra-thin corrugated cardboard, as used for digital tuner boxes, DVD recorder boxes, etc.)
On my (10 mile) test ride, all I could hear was the exhaust.
Now that it's tuned about right,
that sounds good. Piston slap doesn't.
I'm still on the stock head for now, Pablo, until the longer studs arrive.
(Thanks for going out of your way on that one.)
Still, even using the stock head, after going 0.06mm leaner on the main jet and dropping the slide needle to it's lowest, (leanest), setting, along with 4 x 4mm holes on the inside of the stinger/tail-pipe, my top speed has gone up to exactly 50.0 kph, (31.3mph). (44T sprocket, 26" wheel, flat ground, no tail-wind, accurately calibrated speedo.)
Just did my math with the help of 'GearRatio.exe', at 50.0kph, the engine was doing 7280RPM or very slightly less. That's going pretty hard for one of these things.
I don't want to go faster than that but more power will be great.
I'm dying to get the hi-comp head back on. The difference is worth the money. A shame about the stud hassle, but life wasn't meant to be too easy.
A couple of guys are waiting for me to post results on compression, too. My stock head weighs in at 115psi. I still need to re-test the RSE billet head, I think it was leaking when I prevously tested it at 135psi due to the stripped cylinder stud nut.
... Steve