39mm FCR Won't Fit in Boot - HELP

[Quadzilla]

Hi all,

I just got my motor back and got it into the frame tonight and all that's left to do is install the carb, airbox and gas tank. Here is my prob. The 39mm FCR that I have came off of a 99 YZ400F. I've jetted it to about roughly what most people recommend here (50 pilot, 170 main, 3rd clip on needle from the bottom and also did the accel pump mod). I went to put it on and the f'er won't go into the boot on the intake manifold. I even put a little WD40 on the carb and the inside if the boot and still no go. I compared it to the stock carb and it's about 2 or 3 mm larger than the stocker where it goes into the boot. Any suggestions???

[woprs50]

ive seen where some people on here will heat the boot up in boiling water then it goes right in and stays stretched once it cools down

[Chef]

Just stretch it, it will work. I had to take everything out of the inside of mine with a dremel, and boil it for about 45 minutes before it would go on my 41. :eek:

[cals400ex]

boy, i didn't have that problem. i do know it doesn't seem to go in there really far, but it did go in with a little effort. i wonder if that adaptor is different than the ones made for the 400ex??

[Quadzilla]

I'll try the boil thing tonight. I'm also going to borrow a dremel for this just in case the boiling does not do it on it's own. Thanks guys! I'm soooo fricken close to getting this done. I got a new motor and new suspension for this session and did them both at the same time over the winter/spring. Had all stock suspension and stock internals in the motor last year. Should be like riding a whole new quad!

[woprs50]

i just got done putting my 40mm FCR in the boot it wouldnt go in for chit once i boiled it it slipped right in with almost no effort whatsoever