Cheap mod for 400ex engine

[frontman9000]

I have a 99' 400ex. I have a WB e-series exhaust w/Curtis Sparks header and K&N Powerlid on my airbox. I am using a 155 main with a 48 pilot jet. My question is: without doing any serious mods to the engine itself, (which is stock) is there a cheap engine mod that will help me maximize the power of my exhaust without having to take apart and redo the entire engine? Any suggestions?

[Pipeless416]

04-05 450r carb is just about the best bang for the buck mod there is.

[ae13291]

sparks timing key for sure! its only like 30 bucks

Originally posted by Pipeless416
04-05 450r carb is just about the best bang for the buck mod there is.

From what I've read the sparks key and 450r carb is the best budget mods to do....

Do you or anybody know if zrpilot still has any of those adapters? Just seeing because it seems to make it a breeeeze to put on.

The only other thing Im not clear on is properly blocking off the hotstart.

[Sweaney]

I just bought one from him about a month ago. The 450r carb is a great improvement.

[smokindw]

i just bought one from him yesterday!! LOOKS like it is gona be alot easier with his adapters!!!!!GO GET U 1

[dr qwerty]

Originally posted by SuicideMFNdoors
From what I've read the sparks key and 450r carb is the best budget mods to do....

Do you or anybody know if zrpilot still has any of those adapters? Just seeing because it seems to make it a breeeeze to put on.

The only other thing Im not clear on is properly blocking off the hotstart.

Does the carb have to be from a 04-05?
Who sells the the adapter and how much?
What is the sparks key?
Anyone...?

[Newrider08]

Here is what curtis sparks says about the timing key on his website.

I have one and they work GREAT

http://www.exriders.com/vbb/newreply.php?s=&action=newreply&threadid=391417


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.