My jetting experience today

[wvspeedfreak]

I recently installed a HMF Bill Ballance slip-on on my 450r.I also installed 6 of the 1" Uni vents in the air box lid.I was trying to figure out which jet size to start with so with the help of some of you guys I went with a 170.Well I immediately noticed that the bike revved better when it was first started up(I had started it up with the stock 118 jet in it and it popped and sputtered when I revved it up just sitting still).After it warmed up a bit I took it around my track I have on my property and I got to a straightaway where I could open it up and it just flat wouldnt rev up.It sputtered and lunged just like the choke was on.So I stopped and looked everything over and made another lap and same thing,up to a 1/4 throttle it was fine then it was just like you pulled the choke on.I stopped once again,pulled the seat off and completely removed the airbox lid and all I can say is WOW.That thing totally ripped.So either the Uni vents didnt flow as much air as I thought they would or you can get by with less jetting than I thought when just drilling the lid.Anyway,just thought I would share that for what it is worth.

[416rider]

I had kind of the same problem but I got a yoshi trs carbon and the pro design pro flo kit with the k & n and all I did was cut out the part of the lid where the hrc airbox lid is cut. and it helped 100%

[Bill Fuller]

You are to rich try going down in jet sizes till you reach the desired performance.118 to a 170 is that what you said:eek2:

[wvspeedfreak]

Yes it was way rich.The 118 was stock.I put on a pipe and drilled the airbox lid and from what I had gathered a 170 was a good starting point for that setup.What I found was there is a huge difference in airflow going from 6 drilled holes(each 1") with uni vents installed to completely removing the airbox lid.Naturally,an open airbox is going to flow more air,I just had no idea it would be that drastic of a difference.

[416rider]

After cuting the lit out I was told to run 185 with the pro flow and the yoshi.

[Manny55]

I was told to run 185

I run a 185 with an lrd full system k&n air filter with the air lid off. I now have to run a 200 main after i install the esr airbox eliminator kit. I'm waiting for it to cool down and then im gonna go rejet and install and hopefully i will be out tomorrow riding.

[REDARMYRACER]

there has been many people with jetting issues these days.
i have what my signature has listed and run a 190 main, and the hrc needle. she really rips.

the thing i don't like is that once you move from a stock 450r you need to jump a huge amount of main jet sizes.
when you install the hrc kit that bumps the main jet to a 185.

[r450rr]

whats the pro design pro flow kit.. can u explain costs.. and were to get or got any websites or pics//


Originally posted by 416rider
I had kind of the same problem but I got a yoshi trs carbon and the pro design pro flo kit with the k & n and all I did was cut out the part of the lid where the hrc airbox lid is cut. and it helped 100%

[416rider]

It has a bigger K&N Filter billet insert to fit stock intake tube and a outerwear for the filter. the point is better air flow to the carb but the pro design pro flow kit is $20 more than K&N kit I got mine at Cycle Parts west here in so cal.