Wth!

[jake"08"400]

So me and my buddy was riden the other day. His quad is stock except for a k&n filter and a slip on hmf exhaust. My has a sparks key slip on big gun and header weld mod and also a uni filter with a modded air box. So I decided I wanted to see what kind if differnce the sparks key made since I just installed it not long ago. And this is where I'm stumped. He out ran me by a quad length. Take off we was neck and neck he got a lil jump on me but nothing to big. And by thr time we ran out of road he was a quad ahead. After we got stopped I asked what gear he made it to he said 5th which I thought was wierd cause I was in 4th topped out bout to shift to 5th when we ran out if road so if I had more room I would have out ran him top end but I thought the sparks key was for better accel not top end are is the hmf exhaust he have better for low end and my big gun is more of a top end. I'm just confused and agervated cause I wanna be faster all the way around not just top end. Can anyone tell me why that could have happened maybe I didn't make good shifts ? I'm just stumped.

[DnB_racing]

try a couple more runs, you could have had a bad line , swap sides and then swap machines , to find out if its ground conditions or rider or machine

[hybridracer686]

also consider gearing and tire size:ermm:

[jake"08"400]

Gearing,tire size everything is the same. Expect the fact I have more money tied up in mine lol

[chronicsmoke]

Swap bikes and go again, no offense but maybe it's not the bike.

Only more races will give you the answer :cool:

[jake"08"400]

Naw I understand. Only thing is I've been riden longer and racing longer. Also I rode his not racing just riden and the front end pulls up way easier than mine does. So any more suggestions? Like I said I was only in 4th while he was in 5th almost topped out.

[DnB_racing]

Originally posted by jake"08"400
Naw I understand. Only thing is I've been riden longer and racing longer. Also I rode his not racing just riden and the front end pulls up way easier than mine does. So any more suggestions? Like I said I was only in 4th while he was in 5th almost topped out. your not going to get the answer here.

the only place to find the answer is racing him and finding out for sure, you have to realize its not all the machine.
its ground conditions, jetting, tires, rider, body position.

the list goes on and on...

swap lines swap machines,and you will get closer to the answer.

if his front end rises and he still beating you in a drag.... then its your body position. hes riding better then you, but you wont know for sure unless you race him again and try different things

Ive lost many races with quads Ive beat badly other times.. either i just got left napping at the line, or lost traction... but other times left them in the dust,, its not a constant there are many variables

[jake"08"400]

Hmmmmmmmmmmmm...........alright :)

[Stickman400]

I always thought Big Guns were for bottom end. Anyway, with the stock header on that Big Gun you're not gunna get a whole lot of bottom end. You need the header to get bottom end power out of it. I have the Big Gun full exhaust, K&N filter, jetted with 15/38 gearing and 20" tires and I get to 65 damn quick. It's nothing compared to my friends 416 off the line, but it is suprisingly quick for having no motor work done to it.

[finsteratv]

hows the tread on your tires..rider weight?

[jake"08"400]

That might be it. His tired are almost bald there for making them smaller. Mine are brand new Itp gncc tires needless to say full of tread lol so maybe his bein a tad smaller in dia it made the differnce in take off ? And DNB you might be right maybe I wasn't riden to my best cause I thought I would have him beat lol o well like I've said before il just keep upgrading.

[tri5ron]

I agree on the needing a few more runs, swapping lanes, swapping bikes etc.,
But,...
Another thing that you might consider, is that you were in 4th, while he was already in 5th.

Remember, a 400EX stops making any useable power at around 7500 rpm.

if you were running yours out too far,... while he was making shifts in a more optimum rpm range,....
then it makes sence for him to have been only a quad length ahead of you, with you being one gear down.

Many riders here seem to forget that. (I'm not saying that, YOU did that,... I'm just saying it is worthy of consideration).
This is why the aftermarket CDI boxes are basically a waste of money on a 400EX.

Then there is also the possibility that your flywheel was not "Turned to the left", during the installation of your Sparks key.
Does it feel like it has improved/quicker throttle responce, compared to BEFORE you installed the key ?

Did you use a calibrated torque wrench when you re-installed the flywheel ?

Did you have the "Red tip" on the key, pointing outboard/away from the engine ?

I know that it is easy to say "Yes,...it is installed correctly", but are you absolutely POSITIVE ?

Are you SURE your bike is properly jetted ?

Is it POSSIBLE that any of these are a cause ?

Not trying to bash you at all,
Just tossing it all out there as "food for thought".

Best of luck to you, and let us know what you find out.

but first,...
Try a few more times with the previous suggestions of swapping bikes / lanes / etc.

[jake"08"400]

Maybe I was winding it out to much. As far as thr fly wheel yes I'm 99.5% sure that the flywheel is all the way tO the left I held it while I tightened it with a torque wrench set at 80 something pounds whatever spec was idk remember now lol.....As far as jetting yea my plug chops look good...but il re check today. But I prolly was winding out to much....that's for the reply Ron your always a help.

[F-16Guy]

With stock internals, I think your jetting is way too rich. Try dropping the main down to a 152. If it improves, drop it to a 150. Keep dropping it down one size at a time until you no longer see an improvement in wide-open-throttle performance, and then go back to the next richer size. Bigger jets do not always equal more power.

[Pipeless416]

i'm going to be a little bit different here and say that your machines probably make very close to the same amount of power. when i had the sparks key in mine, i honestly don't think it made it any faster in a straight line. it made it snappier feeling, but does this translate to drag race winning power..no. when you really look at your mods list, you probably really don't have much on him, since neither of you have really gotten into the engine.

with that being said, some engines stock for stock are just very strong runners. this could add to your case, giving him the edge.

[F-16Guy]

Back when my quad was fairly new, my friends all had 400exs and mine always seemed a little slower. One day we were climbing this sandy hill to the top of a mesa and mine was struggling while two other guys were having no problem. I was frustrated, so I had a friend try the hill and see if it felt slow to him. He said it did, and then he started looking at the thumb throttle. It had more play in it than his quad, so he adjusted the cable and it was back to 100%!! I just never noticed the increasing slop because I rode it every day. Have you checked your throttle cable? :D

[jake"08"400]

Throttle is good took off the side cover on the carb and wide open has the arm on the slide pulled as far up as it can so it's not that. Checked my jetting. Maybe a tad rich but not so bad I think itl hurt anything in fact it was dead on in the fall when I rejetted the quad and since it was in the mid 60s then and now it's in the high 90s everyday I'd say that's playing a role in it. Also I'm the one who jetted his and put the exhaust on for him so I'm pretty sure it's all right. I do believe it has to do with me winding it out way to much before my shifts but who knows working to much to race him anytime soon. And pipeless I completely agree with you the throttle is a tad more snappy but as far as power sparks key really isn't a great improvement in my book.


That's all I have till we race again anyways and this time maybe il race smarter I guess you would say?

[RNL]

Originally posted by jake"08"400
Throttle is good took off the side cover on the carb and wide open has the arm on the slide pulled as far up as it can so it's not that. Checked my jetting. Maybe a tad rich but not so bad I think itl hurt anything in fact it was dead on in the fall when I rejetted the quad and since it was in the mid 60s then and now it's in the high 90s everyday I'd say that's playing a role in it. Also I'm the one who jetted his and put the exhaust on for him so I'm pretty sure it's all right. I do believe it has to do with me winding it out way to much before my shifts but who knows working to much to race him anytime soon. And pipeless I completely agree with you the throttle is a tad more snappy but as far as power sparks key really isn't a great improvement in my book.


That's all I have till we race again anyways and this time maybe il race smarter I guess you would say?

Thats suprising about the key. Shouldnt an mod that increases torque increase acceleration to? You'd think more torque would equal moving ahead faster?????

[CJM]

Doesnt increase any torque, thekey advances the timing-just makes it rev up quicker.

[jake"08"400]

Yep so it's sort of a waste of time and money to me to even put a sparks key unless you just wanna say you have one.

[chronicsmoke]

Originally posted by jake"08"400
Yep so it's sort of a waste of time and money to me to even put a sparks key unless you just wanna say you have one.

FWIW my engine builder laughed when I showed him the +3 key, he said I wouldn't even feel the difference, but put it in because I had already bought it.

[jake"08"400]

I completely understand why smoke! +6 didn't do anything for mine much less just 3. I mean I guess accel is a little faster but it don't help enough to worry with buying it for anybody that hasn't yet. Although it was fun tearing into the side of the motor it's a great time to inspect you stock key mine was almost out of the slot. Crappy work by Honda lol

[RNL]

Originally posted by CJM
Doesnt increase any torque, thekey advances the timing-just makes it rev up quicker.

Thanks for the heads up, I was just going off what i read about the key. People said it made it wheelie alot easier and gave a nice jump in torque.