sparks key

[Chet]

I am about to get a sparks key, question I have is, will it help top end, as the bike is now when I run it flat out it is weak in the upper rpm scale in 5th gear, If it will hamper top end I will leave it as it is.

[honda400ex2003]

you wont lose any for sure. it will probably help alittle bit everywhere from what i have found out and read about. The most seems to be lower in the rpms but gains are felt in the mid and top also. just my .02 though, steve

[KISSmyACE]

It shouldn't hamper it, the key allows the bike to rev higher in the RPMs... maybe I'm not understanding what you're asking. IMO, If you are looking for more top end, your best bet would be a stage 3 hot cam.

[honda400ex2003]

Originally posted by KISSmyACE
If you are looking for more top end, your best bet would be a stage 3 hot cam.

NO you cant just put in a cam. it is not that easy. you need to do something with your compression with a new piston to run that. it is prefered for stroker motors only anyway. if anything a stage 1 is all you should go with a stock motor. it will help it out a bit. put the key in and see how is after that. if you dont like it hten you can add to it with some other mods like a 450 carb or a cam. steve

[KISSmyACE]

Originally posted by honda400ex2003
NO you cant just put in a cam. it is not that easy. you need to do something with your compression with a new piston to run that. it is prefered for stroker motors only anyway. if anything a stage 1 is all you should go with a stock motor. it will help it out a bit. put the key in and see how is after that. if you dont like it hten you can add to it with some other mods like a 450 carb or a cam. steve

I didn't say JUST the cam lol I said a stage 3 would help with top end if that's all he's looking for.

[TRXRacer1]

Originally posted by honda400ex2003
NO you cant just put in a cam. it is not that easy. you need to do something with your compression with a new piston to run that. it is prefered for stroker motors only anyway. if anything a stage 1 is all you should go with a stock motor. it will help it out a bit. put the key in and see how is after that. if you dont like it hten you can add to it with some other mods like a 450 carb or a cam. steve You know a stg 3 with a key wouldn't be the worst thing. His low end will just suffer. He could easily do a stg 2 and a key.

[honda400ex2003]

ok yes it would help out the top end. but everything else would suffer as a result. steve

[TRXRacer1]

Originally posted by honda400ex2003
ok yes it would help out the top end. but everything else would suffer as a result. steve Not everything. The key is "like" bumping comp. I'll agree it's a stretch on a 3, I wouldn't recommend that either but the 2 would be fine all around.

[rob_990]

i wouldn't do the stage 2 unless you plan on upping the compression later on

[Duf6]

i have a stage 2 cam rest of my motor is stock with biggun rev box and exhaust with KnN filter and dont really feel any bottom end loss just bigger mid and more top end but i still want to up the compression for more power

[TRXRacer1]

Originally posted by Duf6
i have a stage 2 cam rest of my motor is stock with biggun rev box and exhaust with KnN filter and dont really feel any bottom end loss just bigger mid and more top end but i still want to up the compression for more power Thank you. IDK where people get these ideas that you can't cam a stock motor.

[honda400ex2003]

who says that you cant cam a stock motor anyone can do anything they want. is it adviced to put a stage 3 or a stage 2 in a stock motor, no. not by hot cam for the stage 3 nor by any most people i know or talk to. yes a stage 2 you can run with certain things such as a key but is it going to be the best combo for his application most likely not. he has not said what it is exactly so we are climbing a greased rope telling him what is best. if this is the best combo for him then great then more power to him. i am glad to argue against the stage 2 being the best for a stock motor with stock comp. i have just over that at 10:1 and can run with 11:1 416s with stage 2's and others so it seems more beneficial for him to go with a stage 1 with a key over a stage 2 for his application. better yet, he should just put in the key for the 30 bucks and see if it is what he is looking for. if he is still seeking extra power then he can move to a hotcam or something else. steve

[heebs12]

First of all HI! This is my first post. I stumbled across this site after a google search. I got my 400ex abou a month ago and love it. I traded my seadoo hx for it and as vey happy with that decision!

Anyways, back to my question regarding the sparks key....

Will it in anyway way hurt my reliability? I love the fact that our 400's are known for their reliability and would hate to tamper with that!

Thanks in advance,

Colin Hebert

Windsor Ontario Canada

[honda400ex2003]

Welcome to the site heeb. i feel that the sparks key does not effect the reliability of the 400 but actually make it better a bit. it helps to burn the mixture better, this leads to a cleaner better running motor since more of the mixture is getting burned before the valves open. it does create more heat but as long as you monitor it and keep it from idling and such for long periods of time it is fine. just my .02 though. steve

[heebs12]

thanks alot for the reply! I guess a SPAL fan kit would pair nicely with the key to help manage engine temps!

[grassman]

i put the 6 degree sparks key in mine and it definitely took away from the top end.... it gets up to speed a little quicker and is a good mod... i just went down two teeth on the rear sprocket and it took care of the top end.... with that combo i now beat my buddies 05 with all the same mods minus the key and sprocket... thats why i did it... to beat him and it worked....

[heebs12]

Isn't the sparks key supposed to help with top end more than bottom?

[grassman]

Now this is just me but I noticed it helps pull through the gears faster... its just "snappier" if you know what Im saying... it lost some top end definitely... on mine. But with the smaller rear sprocket it ends up being faster and get up to speed quicker.. much better than stock