Breaking in the new setup

[jrok]

Hello everyone. I currently have my 2004 400ex in pieces for a rebuild and I plan on running the tried and true 416 11 to 1 setup with a new stage 2 hotcam with an 05 450r carb. My question is should I just re-jet the 400 stock carb for break in of my cylinder and cam or would I be ok throwing on the 450 carb with a suggested jetting set up? The reason I ask is because I have no experience with the 450 carb and would hate to mess up my break in while fighting with the jetting which, from what i've read, can be kind of a pain on the 450 carb. Any input would be greatly appreciated, thanks.

[bryan1984]

you can go either way. there is a thread on here on estimated jetting for different set ups with the 400 carb, not sure if there is one for the 450r carb. We just built a 440, 11:1 with stage 3 cam and i used My newly acquired 450r carb. we went a little rich off the start which some people say is good or bad on new motor. I would rather start rich on brand new motor than be to lean. just my preference here is the thread

http://www.exriders.com/vbb/showthread.php?s=&threadid=445695&highlight=jetting+placement

go with the stocker.if you had a pipe and filter before the build thats where you would see the most significant jetting change especially when only jumping to a 416.if youre doing build pipe filter all at once i would rejet stocker to like 165 main 42 pilot needle on third clip from the top to start.

[jrok]

I already have a full yoshi exhaust and aluminum box with k&n so I figured I'd just richen the stock carb up a little.

u got it

[jrok]

Thanks alot man!

[WoodTRD]

I was in the same boat with my rebuild going to pretty much the same setup and decided to leave the stock carb in for the break in to play it safe and just bumped it from a 160 to a 170 main. Ran perfect today, tons of power bottom to top. Now that I have about 2 hours on it I'm going to change the oil and maybe start tinkering with the 450 carb tomorrow, starting off with a 175 main and 52 pilot.

[Stickman400]

Another member on here (CJM) has almost the same setup on his engine except for the P&P and stage 2 cam and he ended up with a 168 main, you should be pretty close with a 170 or 172.

[WoodTRD]

Originally posted by Stickman400
Another member on here (CJM) has almost the same setup on his engine except for the P&P and stage 2 cam and he ended up with a 168 main, you should be pretty close with a 170 or 172.

That's where I'm thinking I may end up, but I'd always rather start a little rich than lean. Just finished up boring out the intake boot and the airbox boot, too tight for me even with the adapter. Took it for a spin with the 175 main and 52 pilot and was EXTREMELY impressed just riding it in the yard. Felt like it added about as much power as the piston did. Revs extremely quick and felt a bottom to top increase, jetting felt to be spot on, but I'll ride it some more tomorrow on the lease where I can open it up and check the plug. If you have a somewhat built motor and are debating a 450r carb, DO IT.

dont forget about elevation though fellas.might be comparing close to sea level results while others may not be even close.

[WoodTRD]

True, bout the op is in LA as well, there's only a 500' elevation spread across the state. Of course every bike needs tuned individually, but it should be fairly close. Definitely spray carb cleaner around the boots to make sure you have no air leaks as well. I'll keep everyone updated on what I end up at, but it felt really good. Much more of a power increase than I was expecting, it revs insanely quick now. Pulled the front up from the bottom of third with about half throttle and no pulling on the bars or anything...can't wait to try it out tomorrow with more room.

I would have ended up being ok throwing the 450r carb on at the same time as the rebuild but I still would just go up 5-10 on the stocker if it's running good with it just to be safe. I went from 160 to 170 on the stock carb on mine and the plug looked just about perfect when I pulled it. Started out at 175/52 on the 450 carb and feels perfect but I'll know for sure tomorrow.

[jrok]

Thanks again for all the responses! It never ceases to amaze me, the wealth of information that's on this site. As far as elevation, I'm in Cajun country so I'm at about 14ft above sea level lol! Can't wait to get it all together to experience the gains y'all are talking about. Should be a good bit considering I'm upgrading from a stock piston with a stage 1 hotcam. I was planning on leaving the cam but after much reading here, I think it would be in my best interest to upgrade to the stage 2 now. All the help is very much appreciated, and I'm sure I'll have another question or two before its all said and done.:D