amr rev box and coil

[speedfoxracing]

wut do u all think of these with a stock 400 but jeted with pipe soon 2 be 406 with timing key and stage 1 cam. is this a good investment cause i see alot of ppl have the rev boxs but i,m not runing at a track just trails and on train tracks so let me know thanks

[leasureryan]

I'd like to know 1 thing that a rev box helps. And why is it nessicary and what gains do you get out of it?

[blaaze416]

My quad had a rev box in it when i got it, so i can't honestly tell you what they improve. I will say that I've never had any problems with it in for the 1.5 years i've had her. Cold weather or warm. I believe mine is a Hot Shot(?) brand. I did get the AMR monster coil because I like the idea of having as hot a spark as possible. I heard the coils help with the low end torque, something I may need riding up the rocky ravines where I ride. I think it did actually help with some low end bog I had when riding up hills.

[speedfoxracing]

well i was looking at them on ebay and the rev box was stage 2 and 3 and it didnt really say much diffrence

[krt400ex]

if you get a rev box, make sure to know whether or not it changes the timing curve. if it advances the timing, then you dont want to get the timing key.

i have heard good things about the dynatec rev boxes

[speedfoxracing]

it say it changes the timing curve

[speedfoxracing]

so ur saying it prob wont be the best combination with the timing key then ?

you will be overly advancing your timing which is bad if you use a 6* key and then a rev box that advances it

[speedfoxracing]

ok so i which one do u think i should do the advance key or rev box ?

i personally would use the key and if you wanted the extra RPM get the curtis sparks

[speedfoxracing]

curtis sparks wut ?

[speedfoxracing]

ops my bad lol nvm

[speedfoxracing]

one last question would the timing key be fine with a coil then?
since it wont be advancing the timing

dont know, i assume it should be fine I think there is another guy that has both and it runs fine. You might see a little bit higher temperatures because the coil makes a hotter spark and the advanced timing makes it run a bit hotter aswell.

[speedfoxracing]

ok and doing all this 93 octane will be fine ?

Originally posted by speedfoxracing
ok and doing all this 93 octane will be fine ?

i assume it should be. I wouldnt go over a 10:1 piston though because then you might need to run a mix.

[speedfoxracing]

ok and yea thats the most i,m goin is a 10:1 compression with stage 1 cam at a bore of 406

[speedfoxracing]

quote ((( 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, as a high compression piston will cause overheating issues. 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. )))
thats from the website were i,m goin 2 get my timing key and it says works well with high rev cdis or would the timing be 2 advance. or will it work only with ones that dont mess with the timing curve

[blaaze416]

I'd get the key before I get the rev box if I were you. If you want the extra rpm's, make sure a box you get increases the rpm's and not the timing. Your best bet is proly the Curtis Sparks rev box...since they make the key too. You can call them up and get their opinion. The AMR coil works well with all setups. Never really thought about a higher engine temp because of it, but I guess I can see how it may run a bit hotter. IMO though, not enough to worry.

[speedfoxracing]

yea that stuff my have 2 hold on now cause i might have 2 buy a new berring carrier cause i cant tighten my chain but idk i,ll mess with it some more

[krt400ex]

Originally posted by speedfoxracing
yea that stuff my have 2 hold on now cause i might have 2 buy a new berring carrier cause i cant tighten my chain but idk i,ll mess with it some more

you wouldnt need a new carrier for that. you might have to remove the carrier and just clean out the housing and such, but unless the carrier is butchered up(which it probably isnt) then you wont need a new carrier...

the other thing is that maybe you have adjusted the chain all the way and so you cant adjust it anymore. if that is the case, then you need a new chain and sprockets rather than a carrier