What to do to keep up with the bigboys...

[Impala400]

I am thinking of selling my 400ex to get a Z....before you shoot hear me out, but are there any cheap mods, like cam or such i can drop in and get the performance to keep up and beat a Z while maintaining the stock exshaust? i was thinking a Hotcam stage 2 since they are only like 125 bucks but are they hard to install? Also i am debating to grind the header welds down but need some gaskets before i do it.

[remlapr]

Just get a good pipe, K&N, rejet and you will beat a Z - unless the Z has a pipe :( Probably lookin at $300 total with shipping and everything.

[Impala400]

i have a UNI filter and i am not keen on the K&N w/o an outterwears and i wasn't looking to spend that much.....maybe someday :)

[nojoke4stroke]

Its all about the money.You get out what you put in.Ive ran a k&n for 2 years,ever since i got my quad,in extremely dusty conditions at 2 local tracks and a shut down state quarry and have had zero problems with it.Keep it oiled and you'll get a this film of dust on it,then when it dries a little the oily dust on there catch any dust you might be worried about.Trust me this is the principle behind how they work.As far as mud and water goes an outwear is best but ive never used 1,my filter is currently soaked and caked with mud,no problems but a little backfiring just off idle from the water vapor.Still 2 years and zero problems,no power loss whatsoever. Im sure people will have a lot to say about this but im just telling you my experiences.Whatever you do w/the filter run it without the airbox lid on and and without the spark arrester on the exhaust,this will help it open up from the bottom to the top.Do this combined with a k&n and a jet kit.If you get $300 to $400 to spend go with a 440 kit and a cam.Then when you save some more go with a full exhaust system.By this time you'll be extremely impressed with your setup.Just start small and work your way up,and remember,a good rider on a slower machine will always beat a crappy rider on a faster machine.

[Impala400]

you mean i can free up some power just by taking the spark arrestor out of my stock exshaust and grnd the welds down? i just don;t want to rejet yet.

[toby400ex]

a z aint chit if you are the better rider, heck, ive beaten predators and cannibles out of the holeshot then wooped them all by a lap at my last race.:D

[nojoke4stroke]

yep,no airbox lid and no spark arrester will make it a little snappier down low and let it open up uptop.if grind the welds you mean the head i think is what you said b4 you can deck the head which might require a new cam.Mickey Dunlap of four stroke tech has done 2 "ask Mickey Dunlap" forums on this site and he covered decking the head in there. Do a search on this site,it is very valuable information.

[GlamisEXRider]

I dont understand your way of thinking. You dont want to spend $300 bucks on a new exhaust and k&n air filter but your willing to go out and get another bike. When i had the stock motor i was whoopin on z400's with just pipe, airfilter and vented air box with a rejet.

[RED121572]

Dont take the spark arrestor out.

[SpeedBump]

I would agree with the other guy who said buy shocks. You aren't gonna get that much more punch outta a few mods like that,(filter/pipe) so may as well get some handling, oh ya, in the sand, buy some paddles for sure.

[nojoke4stroke]

i know what u mean glamis i dont understand it either,im the only ex rider in a group of z400's,raptors,a ds 650 and coming soon a predator and i smoke em all day long in the woods and on the track.


why not take it out red121572?

[RED121572]

Exhaust systems are fined tuned for each application. The stock silencer was painstakenly tuned and made the correct length to provide the correct back pressure for the motor. The silencer was not designed to work correctly without the spark arrestor.

If you remove the spark arrestor, your quad will become seriously cranky and turn into an old woman going through menapause. Re jetting is unlikely to solve the problem.

Plus, your thumper will sound like *** too.:(

[Dune Surfer]

If you take off the airbox lid, add a K&N, grind your welds, remove your choke. It will help, but you will, need to go up a couple of sizes on your jet. Don't be afraid to rejet. More air and more fuel=faster quad. also switch to a 14 tooth front sprocket.
If you really want to spank them get a hotcams and a higher compression stock bore piston. Very easy to install and the will only cost about $260 plus gaskets so say $300.
My ex eats Z's. three of my riding buddies ride them and they can't touch me.

[nojoke4stroke]

well actually most of your significant backpressure comes from the headpipe.The purpose of aftermarket silencers with tunable disks is to allow you to finetune the pipe to suit your personal needs.More disks good for low end and more backpressure and a quieter ride,less disks for more high end resulting from less backpressure and a noisy ride,i.e. full race situation.The stock pipe gets most of its back pressure from the headpipe,the spark arrestor is simply that,its there for forestry and usually local state laws.If you had to race with your stock exhaust you'd run it with no spark arrestor for max flow.I and every1 i know runs them like this and have been recommended to do this for max performance from a stock exhaust,none of them have acted up and we've had no problems,i personally,in 2 years of doing this.Seriously man ask around see if im telling the truth.

[Dune Surfer]

It's more disk allows more air through= less back pressure. less disk = more back pressure

[RIDER11X]

Take atvantage of the qualities of the 400ex. Use it's great low end to pull taller/ longer gears by going to a 15 / 36 gearing w/ 20" rear tires.

Use that Honda handling! Buy good aftermarket shocks and go wider if you can with the places that you ride. Top notch tires also are well worth it.

You really shouldn't be getting toasted all that bad by z400's that are stock, as they only make 4hp more on the top end. And the best 400ex slip on only gives a 1.5hp gain with open airbox and a k&n filterWith rejetting.

Hope this helps.

[Castor-426ex]

actually I have about 500 bucks in all the motor parts in my 426 including boring and me spanking off


and...i dont think a piped Z wants any

[nojoke4stroke]

oops i typed that backwards,thanks for keepin me on my toes dune.

[TrX465]

or we just throw in my motor and see how the z's or whatever else u wanna race feel afterwards.....;)

[Impala400]

reasoning behind not spending 300 buy willing to buy a new bike is i don't want to dump a $hit load of $$ into this bike and not be satisfied, and i want to keep the bike stock looking. and i would sell the EX to get a Z and if you do the math the money you will get back on a pipe is like $10 unless i sell it used i am thinking about money that i could possibly get back, and the decidsion has not been made yet.

[RAPTORAZ]

My $300.00 416 has no problem whooping on piped Z's.

Ross 10.8 forged piston and rings $125.00
Stage 2 Hot Cam $130.00
Bore jug and fit rings $40.00
Factory Honda gaskets $25.00

It also has no problem running with stock Raptors or Shee's.

[Impala400]

thats 300 dollars i can justify spending, Personally i think pipes are not worth the $300 in performance relations, and especially when a full Big guns system is 400....

[wilkin250r]

One thing to keep in mind. Valve timing is important to cam design (duh) but you need to understand where that comes from.

When exhaust gasses flow out of the cylinder, they have inertia. This inertia can actually create a vacuum within the cylinder, which will help to pull in a fresh air/fuel mixture. This is called scavenging, and it happens when both intake and exhaust valves are open at the same time. (overlap) The effect is greater at high RPMs. The point of this whole thing is that exhaust flow is very important to the perfomance you will see from an aftermarket cam. The cam design is based around an aftermarket exhaust, which has less restriction than stock exhaust.

I would not recomend an aftermarket cam with the stock exhaust, you may actually lose performance.

[Bunkerking217]

my dad has a z with a full graydon and a k&n. i had a 440 with the WB cam and he spanked me. i took that out, went back to stock sleve, bored it over 1 - 11:1 high compression piston and a hotcams stage 2 cam and i also have a k&n and slipe on WB. i now am 3 bikes ahead when we hit 5th and i pull him til we have to shut if off.......

[RIDER11X]

Originally posted by RIDER11X
Take atvantage of the qualities of the 400ex. Use it's great low end to pull taller/ longer gears by going to a 15 / 36 gearing w/ 20" rear tires.

See my thread "best woods gearing" with my review of the 15 / 36 gearing. :macho :D :cool:

[SANDTRAX361]

have you ever thought about riding more. get off the foram get more sleep ride alot more. the key to being faster is ride ride ride. just think about this. if you beat a Z-400 on your current bike then you save money and met your goal. you can spend 5000 bucks on mods but the best mod you got is yourself. go lift weights. ride a bike. ride the quad. stay in shape and that will be the best mod you can do to beat anybody on the track.
later
Grant Snider
occra#361

[Jekyl_22]

Today I finished my exhaust pipe. I took the stock silencer, took off about 8 1/2", and I took out everything inside of it. It is completely straight through. It it so incredibly short and opened up. I also grinded the welds out of my header. I can't wait to ride with it. I'm pretty excited to see what kind of a difference it will make. No, noise isn't an issue where I live... I must say though, it was quite fun getting to play around with my exhaust.

Also, will I notice any increase in power or a change in the power curve?

[SANDTRAX361]

if you know anything about how motors run you need back pressure if you didnt put any silencer packing in your exhaust then you will actually be losing power. it will seem faster cause anybody whose everybody thinks louder is faster. with out back pressure your motor wont last very long. so i suggest scratching that idea. I had a friend that took teh spark arrester out of his bike to make it louder. and he thought it was also faster. but he thought wrong after i explained this too him.
just my 2 cents
later
grant

[Narly R]

Originally posted by Jekyl_22
Today I finished my exhaust pipe. I took the stock silencer, took off about 8 1/2", and I took out everything inside of it. It is completely straight through. It it so incredibly short and opened up. I also grinded the welds out of my header. I can't wait to ride with it. I'm pretty excited to see what kind of a difference it will make. No, noise isn't an issue where I live... I must say though, it was quite fun getting to play around with my exhaust.

Also, will I notice any increase in power or a change in the power curve?

WOW! It must be like this ( l-----------------------------------------------l ) long!!!!! Hope it sounds sweet! when are ya ever going to get that thing going??? Well mines still down too!:( :mad: I need a axel and a engine, and Ill be ready to go!!!! I founf a guy with a Durablue axel and stock swingarm for $175 but I need to see if the axel will fit......... I might get it this weekend!????:rolleyes: The guy with my engine said he'll be done the second week of aprill or so, and its here!!!!! It might not be too long!!!! Were going to the coast May 16th or sumthin so I think I will be up and going then, u?? Well Ill quit ramblin on! Good luck with the bike!!!;)

[RED121572]

Good luck getting partz for your thumper. Mines down too. I went to slap it all together yesterday. I cussed and screamed for two hours trying to slide the cylinder down on the piston. Ive done it twice before by myself. Something about this 89mm piston. The oil rings are flimsy and get out of wack real easy. This project has been going on since the second week of January......Im about to roll my Honda off a cliff!! :mad:

....time for a ring compressor I guess. :rolleyes: