running 11:1 and advance timing key

[bean2080]

im trying to get everything together and have a plan on what im going to do to my 400ex. i was planning on getting a 11:1 piston with a advnce timing key. i now know that with both of them mods that i would have to run race gas. what octane would i have to run? if it would be real high then i dont want to do that, but if its something that i can just get from the pump then it shouldnt be a problem. also if i do end up picking one or the other what one do you guys recomend getting to get the most power? could i run a aftermarket cdi, like the white brothers with the 11:1 piston? im not wanting to go to crazy on this bike, im just wanting to get a little more power out of it. thanks

[REDRIDDER]

from curtis sparks racing.com

"The 400EX in stock form is very low compression and responds extremely well to advancing the timing 6 degrees. The Sparks Racing Ignition Advance Key advances the timing 6 degrees. There are no side affects from the installation of this key. ............It must only be used in conjuction with a stock piston. This key works great with any other modification, Hi-rev CDI's, performance camshafts, carburetor kits, etc. Just not high compression or big bore pistons...................... We also include a flywheel puller for your convenience. "

[bean2080]

yea i saw that on there site, i know it says stock piston but i was just wondering if you could put a high compression in it. some companys say you cant when you really can, i was just seeing if someone on here did it and had any problems, even though it says you cant.

call them and ask they will tell you high compression is 12.5:1 and up. so its safe to run with 11:1 but race gas will more than likely be required

[blaaze416]

^^^ yup

[blaaze416]

I heard it was safe to run 93 octane on this kind of set up, though. I only have a 10:1 piston, i know, but i haven't had any problems.....yet. Then again, i could be wrong....:eek2:

[bean2080]

thanks for the replys guys, ill give them a call.

[bcg717]

Let me know what they say because i was going to go to a 416 with 11:1 and i already have a TA Key.

[bcg717]

Originally posted by blaaze416
I heard it was safe to run 93 octane on this kind of set up, though. I only have a 10:1 piston, i know, but i haven't had any problems.....yet. Then again, i could be wrong....:eek2:

How do you like your 406? Would you recommend just going to a 416

[blaaze416]

I really like my 406. A wake up from the 400, but i do think I would have rather gone with a 416 or an 11:1 piston. Then again, i don't have a 416, have never ridden one, so therefore can't truly say. I am just wanting a little more from my set up. I may put the stock cam back in to see what the difference is from the loss of compression from the stage two cam. Most of my riding is in the trails and up the hills, so I don't really need as much top end.

[bean2080]

bcg717, they said that they do not recomend running a 11:1, but they didnt say not to. ill have to think about it and deside what im going to do.

[Chino886]

I ran a 10.5:1 and the Sparks key and it ran great.