2010 weapon

[richban]

Ok, what you have is called "open loop" (basically, this is an older system that does not use an o2 sensor to calculate, and adjust fueling, it relies on a predetermined fuel curve)

It's simply a cheaper system.

take your header in to the muffler shop, and simply get them to cut the cat out, and replace it with a straight bit if tube (inexpensive really).

I guarantee you you will gain power, and won't have problems with fueling.

It's been done before.

If you make the header 660mm long from the valve then into a good muffler that should work nice at 10000 rpm if it makes its power in another rev range add 50mm to move power down the rev rang (ie 710mm header length = 9500) or shorten it to move it up the rev range (ie 610mm header length = 10500). Header dia I would leave as standard 4 now. Bigger might not be better for you yet. A good header length for an FXR is around the 500 550mm from valve as they make there power at higher revs.

[Rick 52]

Now that is very good advise max read it more than once .

[Kendog]

This forum may help with info, it seems to be pretty active.

[Buckets4Me]

http://www.aseanmoto.com/images/CBR-159cc-L.jpg

just cheat these guys to a 190cc kit as well
http://www.aseanmoto.com/images/CBR-197.5cc-L.jpg

and to keep people off your back
http://www.aseanmoto.com/images/NMF-Titanium-L.jpg

[woodyracer]

OK, i jsut took to the aroudn the block, it goes great!, at first i thought, this feels un responsive, but after gunning it a few times, the whole engine rev's have changed, now it likes being short shifted {not revved out} and now it pulls away better in 3rd from a standing start {which it couldnt do before}

Also it's not loud!, as now it almost gets quieter when your riding it, I realy do like the bike like this, as it pulls better and has a much better ommff when you pull back the accelerator.

There is room for the better exhaust system, but at the moemnt its not my top piority, as the bike is fast enough as it is.

[gav]

If you make the header 660mm long from the valve then into a good muffler that should work nice at 10000 rpm if it makes its power in another rev range add 50mm to move power down the rev rang (ie 710mm header length = 9500) or shorten it to move it up the rev range (ie 610mm header length = 10500). Header dia I would leave as standard 4 now. Bigger might not be better for you yet. A good header length for an FXR is around the 500 550mm from valve as they make there power at higher revs.

Do you recommend a standard header diameter size for the FXR as well? Is there any advantage with a larger diameter header pipe?

[woodyracer]

My header got made bigger my "customchambers" and he knows what he's doing so i guess it is better to makei t bigger

[richban]

Do you recommend a standard header diameter size for the FXR as well? Is there any advantage with a larger diameter header pipe?

With my worked engine I have gone up one size and staged it. Its 1" 1/8 for the first 200 then 1" 1/4 for the next 100 and then 1" 1/2 for another 100. Then into me fruity muffler. Its all unproven but the bike is going good. The engine is designed around peak torque being 12000rpm. Max horsepower should be above the limiter somewhere.

[woodyracer]

my bike is running a 1" straight through pipe to a steal muffler with a 2cm opening

beat that

did i mention its got usd fork??, hahha serious performance

[gav]

Thanks for that, looks very neat!

[gav]

my bike is running a 1" straight through pipe to a steal muffler with a 2cm opening

beat that

did i mention its got usd fork??, hahha serious performance

You shouldnt steal mufflers Max ....

[woodyracer]

Thanks for that, looks very neat!

why thanksyou, i think it turned out good.

[woodyracer]

You shouldnt steal mufflers Max ....

i am speaking chinenglish......duh!

[richban]

Do you recommend a standard header diameter size for the FXR as well? Is there any advantage with a larger diameter header pipe?

Gav. I didn't really answer the question coz the truth be told I don't know. Its one of those how long is a peice of string questions.

[woodyracer]

the advantage with a larger header pipe is "back pressure", so basicaly what you want is a pipe sized to accomodate both back pressure for bottom end and a pipe that isnt too fat so you can get top end power. The standard diameter on a fxr is good, but its double wall steal so its better to get a new one made so its lighter. But for kart tracks i find you want bottom end over top end, so a nice big fat header is nice.

The "bananna" bucket has a huge fat header and a 1" straight through muffler, it may pop wheelies like no other gs125, but its got no top end so you are left for dead on the straights. Its down to "What do you want your bike to do?"