off topic kinda - exhaust mods

tokarev · 12-10-2007, 09:39 AM

Last night we modified my sons pocket bike pipe - had to reshape radius around the head - split the expansion chamber and moved the front cone foward. Added 2 1/2 inches to the center. This goes along with a bunch of other engine mods he did. Hope it works OK - the engine that is. He wants to ride it this weekend in a Christmas parade.

warrior91 · 12-10-2007, 09:59 PM

looks good. :o obviously it must be 2 -cycle.

Mike38 · 12-10-2007, 10:19 PM

Is there a reason why you did this? If you change the dimensions of a two stroke exhaust pipe, it can drastically change the engine performance. Four stoke exhaust is relatively fool proof, but there is a science to two stoke exhaust.

czowner · 12-11-2007, 03:11 AM

Quote:

Originally Posted by Mike38

If you change the dimensions of a two stroke exhaust pipe, it can drastically change the engine performance.

I totally agree, but extending the front cone usually improves mid-range.

Jonathan.

tokarev · 12-11-2007, 10:45 AM

Mid Range is what hes looking for - My son researched the pipe mods - I made it happen (cutting/welding) Hes made a bunch of other mods to the engine in addition to the pipe. Started the engine last night - test ride this afternoon - YeeeHaa

tokarev · 12-11-2007, 04:39 PM

Well I rode it today - all 240 lbs - worked fine
My son is 60 lbs lighter

Besides that it has a lightend flywheel, slightly tapered carb, triple stage black widow reeds, better air filter, DDM headkit w/ 2 boost ports, NGK spark plug wire/boot, homemade boost bottle, and third gear support.

12-10-2007, 09:39 AM	#1
tokarev Join Date: Sep 2007 Location: Safety Harbor Florida USA Posts: 214	off topic kinda - exhaust mods Last night we modified my sons pocket bike pipe - had to reshape radius around the head - split the expansion chamber and moved the front cone foward. Added 2 1/2 inches to the center. This goes along with a bunch of other engine mods he did. Hope it works OK - the engine that is. He wants to ride it this weekend in a Christmas parade.
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12-10-2007, 09:59 PM	#2
warrior91 Join Date: Nov 2007 Location: N.E. Saskatchewan, Canada Posts: 679	looks good. :o obviously it must be 2 -cycle. __________________ '91 Yamaha Warrior- stage 2 '83 Honda ATC 70 '08 Yongjiang 125cc mx (Loncin) '08 Yongjiang 150cc atv (Jinlong)
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12-11-2007, 10:45 AM	#5
tokarev Join Date: Sep 2007 Location: Safety Harbor Florida USA Posts: 214	Thats the ticket Mid Range is what hes looking for - My son researched the pipe mods - I made it happen (cutting/welding) Hes made a bunch of other mods to the engine in addition to the pipe. Started the engine last night - test ride this afternoon - YeeeHaa
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12-11-2007, 04:39 PM	#6
tokarev Join Date: Sep 2007 Location: Safety Harbor Florida USA Posts: 214	the bike Well I rode it today - all 240 lbs - worked fine My son is 60 lbs lighter Besides that it has a lightend flywheel, slightly tapered carb, triple stage black widow reeds, better air filter, DDM headkit w/ 2 boost ports, NGK spark plug wire/boot, homemade boost bottle, and third gear support.
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12-10-2007, 10:19 PM	#3
Mike38 Join Date: May 2007 Location: Illinos USA Posts: 12	Is there a reason why you did this? If you change the dimensions of a two stroke exhaust pipe, it can drastically change the engine performance. Four stoke exhaust is relatively fool proof, but there is a science to two stoke exhaust.
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