Main jet question for my project.

[joey]

Gday,

I look for a while on this forum, but i didn't post a lot.
I'am building a http://www.fzrclub.nl/smf/index.php?topic=16598.0 project (i'am from Holland)
I try to build a exhaust 4in2in1 system, i will soon post some pictures
And i try to build a airbox, the told my it's almost impossible to ride it with only Pipercross/KN filters, has anyone here tips.
But now it runs with original jets, i think with my new exhaust en airbox it will run to lean, an will maybe damage my engine.
In my neighborhood, there is now dynorun (an it is quite expensive).
I thought maybe i can do already a few modification mainjet an i heard about drilling a little bigger hole in the diaphragm??
Maybe you tunners have a few suggestion.

Sorry for my bad/poor english.

Friendly greetings,
Joey

[taggy]

it might be expensive but a dyno will set things up properly and stop you damaging things which could be a lot more expensive in the long run! you will almost certainly need bigger jets and to adjust the mixtures etc. you could try trial and error but you could be chasing a good setting for ages!

[yamaha_george]

Hi,
there is a fix for running pods look under my posts for the details, I already have 4-2-1 exhaust and did not have to change jets.

You never drill jets see :- http://www.saltmine.org.uk/martin/jet_sizing.html look down page for details as to why