Installing upgrades help with setup

[ToolJunkie]

Hey everyone I have just ordered some parts for my '07 400ex just want some advice where to start with jetting after I install the parts. Should I leave the 6 degree timing key with the new cam? New parts consist of:

K&N air filter with outerwear (no lid)
Hot Cams Stage1
White Brothers E-series full exhaust
AMR S2 cdi
Dyno Jet kit

Elevation 4500-5000

[BigLuke]

Well with the CDI it will prolly advance your ignition as well so I would say pull the key. And with the filter and pipe I would start out with a 155 main with the clip on the second down groove of the needle. 2 1/2 turns on the mixture.

[hondaking52]

you can leave the key in, my bud has both and they work very well together.

[rob_990]

Originally posted by hondaking52
you can leave the key in, my bud has both and they work very well together.

same here

[bigbad400]

i also have the key and the same cdi and i love it, works just fine and nice gains in throttle response and defiantly has more pull. i would get a crf450 cam chain while your doing the cam, the stock ones are known for stretching, mine is now i think and i need to switch it to the crf450, its the same as the HD 400ex cam chain, alot stronger and way cheaper than the labeled HD ex chain. also a good suggestion, do one mod at a time, that way you know the gains of each accurately, i actually liked the feel of my cdi over the sparks key. more is said to be gained from the key but mine responded much better to the cdi, i also would recommend the amr monster coil, mine started easiest after that mod, cant say anything for gains but starting easy is important to me. good luck and fun riding

[ToolJunkie]

Just thought I'd update this in case any one was interested.
I installed all the parts one at a time to see what the gains were going to be. I also used the stock jet until all parts were installed and 6 deg timing key.

1- Installed K&N air filter wow what a difference seemed to be more responsive although I didn't notice any significant power gain.

2- Installed AMR rev box, This was a real improvement on throttle response and It seemed to gain some in overall speed. Didn't seem to help with starting but mind you I still had the stock jet.

3- Installed Hotcams stage 1. Holly crap! Big noticeable difference. Although running way too lean. Within 2-3 minutes the stock pipe was glowing red. Had to shut it down and install jet.

4- Installed new 165 main jet and needle and adjusted mixture screw. Now I followed the Hotcams break in procedure. Major difference even with stock exhaust. After first 20 minute break in I decided it was time for the next step.

5- Installed White Brothers full exhaust system (that I bought used on eBay and repacked when I received it) while waiting for engine to cool. I would recommend waiting for it to cool first but the excitement was overwhelming. I was able to grin and bare the hot muffler and pipe during the removal of the old stuff.

All ready for the final break in. Started the bike wow this baby sounds mean. Finished the break in. I didn't want to get on her too much until the break in was finished but I can tell a big difference between the stock pipe and the White Brothers.

My son and I were able to get out last weekend finally. I took it easy for an hour or so just to let it break in a little more. I noticed that there was a slight stumble and a bit of a kick back when starting but all in all she ran great.
When I got into the throttle in 2nd she stood up a bit. Wow I didn't think she'd gained that much. So I started riding a bit harder. By the end of the day I was impressed with the upgrades and I'm very happy with the performance gains.

When I got home I pulled the plug and it looked like it was a bit more red than I liked so I removed the 6 degree timing key. Now the bike fires before you can pull your thumb off the button (3 pumps of the throttle, no choke, split second on the button). The kick back when starting is gone and the stumble in the throttle has gone. I have since checked the plug and it looks great.

In case anyone was wanting to get a bit more out of their 400EX I'd definitely recommend similar upgrades you won't be disappointed.

Thanks to all of those who gave their help here.

I think I'll do a 416 or 426 next year :)