Exhaust Jag pipe on 66cc

wagel

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Aug 4, 2016
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Tried Jaguars pipe design from his website. As I had to use what materials I could find locally then it is not 100% accurate. The ID of header pipe is 22mm and stinger is 14mm. Looks like this.
DSC_3889.JPG

Feels like I got some power gains down low as it seems to accelerate a bit better but top speed went from 40km/h to 42 so no apparent gains there. Hope some porting adjustment does the trick. Any ideas?
 
jags pipe is designed for torque i believe not top speed. looks pretty good although i would grind down the welds a bit is it loud?
 
I will grind the welds at some point if I will keep the pipe but have not decided yet. Also plan to paint it black but I didn't want to put in too much effort before I have tested that it actually works and performs. At the moment the whole bike is just a test platform for the engine. In near future I plan to get a decent MTB and then depending how stuff fits make a new pipe or adjust this one.
It is really quiet at idle but makes some decent noise at speed so if someone wants to fly below radar and not piss off neighbors early morning or late in the evening then a silencer is needed.
 
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Stock intake port duration is too little. Increase it to 120 degrees open.
After that if you still want more speed then raise the exhaust port 1mm at a time till it's where you want.
Make sure your main jet is optimized for speed. Too big or too little will limit speed. What color is the plug?
 
Will take the jug off next time when I have time to mess with the bike and measure current porting and start dremeling. The plug at the moment is black but its the same plug I used with a bit bigger jet and stock exhaust and then it was black and moist :D so might be that it hasn't burned clean. I have a mikuni VM18 with main jets from 55 to 95 if I remember correctly but haven't had time to fab an intake to use it. That's going to be on my list soon.
 
it doesn't take long to change the plug color with a jetting change
 
I thought so. Also its intermittently 4 stroking at max speed WOT. I'll try to fix it with the mikuni.
 
the fix is a smaller jet, not a new $80 carb
What I meant was that I'm not going to waste time on fixing the mixture issue of the stock carb as I have the mikuni with buch of spare jets on the shelf anyway and it would be more reasonable to spend the time on fabricating an intake for that one.
 
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