Ported 48cc!

stv1jzgte

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Feb 23, 2009
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Hi All, Have been tweaking my motor bit by bit and have heard of the benefits of porting the larger 80cc or 66cc. I wondered if the 48cc had the same prob with the piston covering the top of the port, well i pulled the carb off and sure enough it does but by not as much as ive seen the 80cc only about 2-3mm.
So with dremel in hand i got grinding! i lowered the inlet by 3mm and widened it by more than that on both sides the exhaust i went a lil more, i only cleaned the transfer ports. Re-assembled and went for a ride.
First difference its louder! heaps!
Power wise its is a lil better down low but as reves climb and climb and climb it gets louder and smoother! it feels like it revs alot more. I know it sound dumb but it feels stronger also, like i wont blow it up .... famous last words!
i set a new top speed of 59.2kmh or 36.5mph my previous was 52kmh i use to hit it like a wall every time.
Will have to wrap better cotton insulation in the exhaust to help shut it up a bit.
Regards,
steve
 
That is a nice increase. Have you tried 2 stroke packing for the muffler ? A few more holes in the tube seem to help mine out a lot.
 
custom

That is a nice increase. Have you tried 2 stroke packing for the muffler ? A few more holes in the tube seem to help mine out a lot.

Well i allready made a new centre section, inner tube and end cap about 100mm longer, it was quiet before i ported it!
At the moment i have filled it with fibre glass but when i have the time i will be getting the cotton insulation from mca (motorcycle parts shop) for 2 strokes!?

This pic is the muffler as of now 11mm outlet, i have tryed 17, 15, 13mm by drilling out a nut and welding it on the end

P7260073.jpg
http://i429.photobucket.com/albums/qq14/stv1jzgte/P7260073.jpg

This is the origional centre and end cap. the peice below it is the end i chopped off a bit i drilled and then bent the holes in to direct the air to the insulation, this sits in the centre of the outer can with a sorta cone at the inlet end directing air through the tube.


P7260074.jpg
http://i429.photobucket.com/albums/qq14/stv1jzgte/P7260074.jpg


P7260076-1.jpg
http://i429.photobucket.com/albums/qq14/stv1jzgte/P7260076-1.jpg
 
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whats that end cap?

can anyone guess what the end cap of the muffler i made is???????????
 
awe... so move it

Can anyone guess why this is in the bicycle repair section instead of the 2 stroke section? I sure can't.

Wow your all over it! you should be a token administrator!
If the real admin wants to move it im all for it! :cry::cry:
steve
 
strong!

so, still going strong ?

Hey, yeh all is good with the motor sorta! though i have have a few problems in other areas, friday my rear mudflap that i made:whistle: snapped off (again)taking with it the left hand brake lever arm and pad, i didnt hear or see it because its so dam loud now and didnt really notice the braking loss till i got to work... "wheres my mudflap oh **** my brakes!" That fixed yesterday buzzing along the m7 i heard a loud ping! i instantly lifted my feet thinging it had blown up! still running i went back to where i heard the noise and there's my front mudflap that i made:whistle: snapped off!
From 30-50kmh it has alot more vibration but from then on it smoothes out till it just wont rev anymore at 59.5kmh.
All this vibration is slowly rattling my bike apart.
The worst would have to be that because of this the float bowl needle gets itself stuck up in its seat, ive hit it with 1200 wet n dry and polished the **** outa it it still gets stuck!
Time to upgrade to the CNS carb, though the local seller wont stock them anymore because he cannot provide any tunning data for them so i have to go elsewhere. ramble ramble ramble my fingers hurting.
steve


Edit update 4 hours later: chain fell off. Now looking into a spring adjustable tentioner!
 
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