running of straight through pipe

[cbr_veze]

hi folks, i fitted a bolt on pipe the other day that has no baffle in it. it is bolted on to the standard factory 4-2-1 system. The carberettors are running standard jets and the needles have the factory washer in, and the pilot screws are set at two and a half turns out. the carbs are nice and clean, but are weeping a little bit, but are nicely balance. the bike doesnt run to badly. under induction it isnt to bad. is is just a bit spluttery at low revs, on the over run it doest sound to bad. i was just wondering whether it would need dyno jetting. seeing as though its not running too badly, i wouldnt think it is running too lean. i was wondering whether someone could give me a bit of advice, cheers folks.

[Mikiboy]

it is likely to need jetting on a dyno. Dont pay for dynojets as you pay for the name. The dyno should be able to supply and fit there and then. If it seems fairly good, there's no point in spending a fortune getting it perfect, but best get the reading on the dyno 1st.
Roj at Corby Kwak has dealt with a lot of 400's on the dyno and won't rip you off by telling it needs doing if it doesn't. 01536 401010 and ask for roger.

[cbr_veze]

ahh cheers matey, im only down the road from corby so i will give him a buzz. what is the alternative to dynojests?

[bourney]

ahh cheers matey, im only down the road from corby so i will give him a buzz. what is the alternative to dynojests?

Just jets.

All a jet is is basically a screw with a hole in it.



Sorry to steal the thread but no point in making another for basically the same thing.
Anyway. I've got a scorpion end can on my bike. I pulled it apart yesterday and pulled out the baffle. Basically a massive black thing LOL.
So now i've just got an empty can!
I reckon it will run shit like that though, right? So i was wondering should i just buy some perferated baffle tubing the same diameter as the end piece of my can. Shove it in and pack the sides out with exhaust packing/house insulation?
What do you guys do???

[lloydiecbr]

you will need to pack it . the packing is only a fiverish from busters then all you will need is some perferated baffle tubing . this is how race cans are . the tighter you pack it the loulder it gets

[bourney]

you will need to pack it . the packing is only a fiverish from busters then all you will need is some perferated baffle tubing . this is how race cans are . the tighter you pack it the loulder it gets

Ok, so to put it basically.

I measure the external diameter of the tube on the very end of the can (where the exhaust gasses exit.

I buy some perferated baffle tubing a mm or 2 larger than the diameter of the tube on the end of the can and the same length (ok well slightly shorter) as the exhaust.

I stick the baffle in and screw it in/weld it in. I then buy some exhaust packing and pack it around the outside of the baffle as tightly as i can.

So i end up with this basically-


Sorry for the rough picture but you get the idea lol.

[lloydiecbr]

yes just like a polo mint

[bourney]

yes just like a polo mint

a brown polo?? eeewwww... do i even want to know where that poor polo has being?? LOL

[missinNZ]

i have an ART 2 inch straight thru on my bike, with bs stamp, no baffle (or even a fitting for it). the only difference between mine and your diagram is just into it where the exhaust bolts onto is a 'bulb'/chamber thats around 3" around, dont know what it does or why but shes pretty loud.