2/stroke is 4/stroking?

[AussieSteve]

That looks the same as my muffler. Doesn't the end-cap come off when the screw is undone?

 

[geebt48cc]

I took base of muffler off.....................................WOW, 2/3 power gain!!!!!!!!!!!!!!!!!!!!!!~ WooHoo, for a big 49cc.......................................


Will climb any HILL!!!!!!!!!!!!!!!!!!!~

 

[AussieSteve]

I drilled a couple of 4mm holes right through the thin outlet pipe, just inside the end-cap, to allow some of the exhaust to bypass the baffle.
There was a definite improvement without too much extra noise.

 

[geebt48cc]

True, that works Steve!!!!!!!!!!!!~.......

........but now, I've got a (VERY LOUD) 48cc bike.

Ok, power or quiet?

That's the question?

 

[AussieSteve]

The way I approached it was to drill a hole then test - repeat until it was the loudest I wanted to put up with. As I said, in my case 2 holes right through the tube was about right for noise.
Could have got better flow/more power by drilling more but it would have crossed my noise threshold.
(Got an expansion chamber here now to fit when I get a chance.)

 

[GearNut]

With all of the negativity that some folks are dealing with concerning gas powered MB's I recommend AussiSteve's method. A little more power and it is still relatively quiet.

 

[AussieSteve]

That's my concern with the expansion chamber.
I'll wait and see. Hopefully it's not tooo loud.

 

[geebt48cc]

Once again.....................Absolutely fantastic power for only a mere 1.95 HP? BIG 48cc!~

 

[jarz24]

i try drilling holes in the muffler wow it made a huge diffence. it's alot louder but it sound mean as and wow the power cheers guess it fix so many problems

 

[geebt48cc]

2/stroke after 17 mph goes 4/stroke?

Hey gang,
Everything's running well (49cc Skyhawk), but after about 16-17mph, motor starts 4/stroking. I have big time gone over it for air leaks.

Ok, same gas ratio mix as of 2 weeks ago 25:1 ,and would run in the lower 30's mph? Needle is in the same place(2nd down from top)....Mmm,

Oh, I also put a new plug wire on (better in quality). A new plug cross over from NKG------ Autolite 4093 ....gap 0.20 , stock muffler with one drilled hole at base.Took air box off, only using foam filter. (Much more air flow)

So, I thought high speed jet, but it ran at speed a few weeks ago with everything same/mix 25/1.

PS- It had original (CHINA) everything when it ran faster?

Sense new, I've ran about 4 full tanks.

TY, Glen Ideas welcome.