Instead of cluttering up the FAQ section, you can ask your hop-up questions here.
Thanx!

thanks for the thread. sorry about the clutter, but I was directed to that thread by another member.

I have an 06 KFX. I just installed a Full HMF system, and a Pro-Power up kit that includes K&N, billet adapter, and outerwear, I sit between 3800-4200ft elev.

w/ that done to it, it idles well, it runs pretty well up to about 3/4 throttle then it just falls on its face (lean I believe.)

From what I've searched and read on the site, I figure up the main jet some and work from there only for these mods and because of how its running. Am I correct in that?

I plan to remove the snorkel, get a better flowing air boot, and get a screen lid. W/ these mods I remember reading I would probably have to play with the jet needle. Am I correct in that?

Anyone think I would have to play with the pilot jet as well?

I have a Dynajet Kit at my disposal that incleds liek 10-12 main jets, an adustable needle, but no pilot jets. anyone know where I can get these?

My KFX is 2 years old... and I guess I sorta beat it pretty good.... but anyways, I was riding up in Tamaqua on one really hot day (like 90 degrees +) and we were going through some rocky sections of trail for a while and I was in 1st or 2nd gear most of the time. Ever since then my quad has been making a loud ticking noise, sort of like maybe the valves ticking or timing chain or something?!? I dunno, I'm not a real big motor head. But has anyone else run into this or know what it might be? I'm supposed to race a harescramble this Sundayand I'm really itching to start racing but I don't wanna blow my bike up. Reply or email me at XSPYDER01@aol.com. THANKS DUDES!!!!

Since you are speculating that it might be the cam chain or valves I am assuming you have eliminated the drive train and that the ticking occurs in neutral and increases its frequency when the engine rpm is increased, correct me if I am wrong on this.

I would say you are probably right with your guess. You should remove your cam chain tensioner as per the service manual and make sure you have at least 3 clicks left. You should also take off the valve cover and make sure your valve clearances are within specifications.

Another thought, have you removed the flywheel and replaced the bolts as per this thread?

Hi, I'm new to this forum and so far have found it very helpful. Thanks to all for sharing their knowledge. I just bought an 03 Z and have a couple questions:

I ordered an HMF slipon which comes with "required jets". I plan on running a UNI filter and EHS lid. What main do you reccomend? Is the pilot screw the same thing as the A/F screw and if so how many turns out does it need to be? What is it set to by default? (2.5?)

I live in central NC at approx 900ft elevation. Any input would be GREATLY appreciated!

THANKS EVERYONE!

any jetting suggestions for my quad would be appreciated. runs super right up to the point when you want to shift then is sputters out until you let off throttle. 190 main and on the fifth rung down on the needle. is there a lord of jetting around???

I was just wondering if anybody here has run there z with the spark arrestor cut of because i was thinking of doing that, before i get my full yosh exhaust, to gain a little power?

I wouldnt. Mine is off and it doesnt run very good. I think it has overheated and caused motor damage.

Can someone please help me i just put in web cams and my motor wont run. it did run for a while but then it got to the point were it wouldnt run at all.

You guys are my last resort, I don't know what else to do...
Please help me with my 2005 Z400

I went riding the other day, and the bike ran great as usual, no proiblems at all. After the ride I washed it and stored it away. The next day, I went to ride again, I started it to warm it up and I let it iddle (started on the first try as usual). After a few minutes the bike stalled and never started again!
I have spark, I have gas, air is not an issue. I took the carb apart and cleaned it, it was a little dirty, but nothing staggering.
Everytime I took the bike a part to check something else and then put it back together, it would again start on the first try, but then again stalling after a few minutes and never starting again. If I try to work the throttle to keep it from stalling, it breaks up real bad, sputters and when I try to start it again it back fires. This has led me to the conclusion that once the bike gets hot it doesnt want to run. ( the fan works by the way)
So now i'm thinking the stator went bad, right??? WRONG!, I just put a brand new stator in it, and it still does the same thing again.
I've played with the jetting and carb settings... that does not seem to be the problem.

As far as mods, the bike is an exact replica of Digger Doug Gust's bike from the 2005 season, from tires to hand grips. I love this bike, it is very fast, and i've won plenty of races leading from holeshot to checkerd flag!

I DON'T KNOW WHAT ELSE TO DO... other than tear my hair out!
PLEASE HELP ME!!!
Thanks

Have you checked to make sure your fuel lines arent clogged? Have you checked your magnesium clutch cover to make sure there arent any pieces of metal floating in there clogging up your lines? just a few things that might help, good luck

Hy guys,
Im brand new to the forum and to the z400 bike.
Can you tell me about the item called "phoenix performance spark arrester"?
Does it do any good (gains power) or its just another sound product?
Should I change on my z400-2005 just mg. cover or also the water pump?
Thanks

04 z400 stock engine wb eseries 12 disc full system k&n dynojet kit wb rev box need to talk to someone on a way to jet for trail riding

If you have a DJ kit try a 165 main, needle on the third clip, and 25 pilot w/ 2.5 turns out on the fuel screw.

DJ's numbers dont match Mikuni's for mains---a 165 DJ is equiv to about a 155 Mikuni---

I have a water pump leak on my brand new (used) 2003 z400 and have a question about this.. I bought the bike from a shop that told me after the fact that it has a leak and was going to fix it no charge. When I persisted in finding out more about it I found that the leak also bled into my oil. So now that I know that I had anitfreeze in my oil (the mechanic said not a whole lot) Im wondering if Im going to have to look into a new crankcase bearing?? Is this a typical thing with the z's?? And should I try to figure a way to have the shop that sold me the bike to take it back???I've been told this is the sight to go to when it comes this type of question. please help. Thankyou

i dont know if u have figured it out yet but i am running a full system hmf bill ballance and pro flow w/o air box lid . the solution for me was the pilot . dont mess with the needle . i put a 25 piolet in and it runs awsome with a 168 main . u can get a pilot jet at any local quad shop .

Hey guys, I'm a newbie here, and I just had a few questions about some mods I was looking into. First of all, I was wondering if there was a big performance differnece in the yoshi pipes, particularly the RS series and trs? As of right now I'm planning on getting the youshi RS3 carbon full exhaust, with a pro power pack and tag x5 bars, should I do it?

Has anyone ever been successful in using the lemon law to get a full refund for their 2006 ltz400?

Okay guys I Am a Newbie. I have been racing since i was 13 but i am still having problems perfecting a couple things with my 400. Currently i am running VP C-16 mixed with a bottle of heat 104 in my quad. i was wondering if there was anything hotter that i can run without putting an alcohol carb on my 400? and the other thing is that i am having trouble getting hooked up correctly with my holeshots. I have tried Fast trekkers and Hoosiers but i can't find anything that hooks up just right, everything hooks up too much or not enough. I Flat Drag in Southern Indiana and Northern Kentucky. I have to find a happy medium for a tire i was wondering if you guys had any suggestions. thanks

What do you have for mods??? That is pretty important for choosing fuel.

Just remember, More octaine does NOT mean more hoarse power!!! Throw the octaine booster away, cause its a joke!

If your engine is stock then there is absolutely no reason to run any fuel higher than 89-91 octaine, and thats on the high side because 87 is fine for a stock Z

I agree about the octaine boost. And vp-c16 is way to much for almost any mod unless your runing nitrous.

OK i just picked up a 05 z400 and got some new wheels but i can't find the torque specs for the wheels anywhere i was wondering if anyone knew what the torque specs are?

In the service manual.

Has money for wheels, but no cash for a manual?

Time to spend $30 on a $6000 machine!

DOSE ANYBADY KNOW THE BOLT PATTERN FOR AN 06 Z400 AND A OLDER STYLE 400EX?

Assuming you mean wheel bolt pattern? If so, the fronts are 4x144mm and the rears are 4x110mm. That applies to all years of Z400's(and it's clones), 400EX's, 300EX's, 250EX's, 250R's, 450R's, Cannondales and 05 and up Predators.

ok I have a kfx400 what are the cheapist mod's from the highest mods? I want more Power
u can reply or email me at Jonhyboy@comcast.net

Stage 1 ($400-$750):

- Remove airbox lid, get K&N filter lid, drill holes in lid, or buy eliminator kit + K&N or Uni-Filter
- Full exhaust system
- Jet kit or applicable jets

Stage 2 (S1 + $300-$600):

- Stage 1 plus
- Intake cam (optional exhaust cam)
- Ignition
- Heavy duty valve springs (Suzuki DRZE)
- Heavy duty cam chain
- DRZE base gasket

Stage 3 (S1 + S2 + $125-$300):

- Stage 1 & 2 plus
- High compression piston

Stage 4 (S1 + S2 + $875-$???):

- Stage 1 & 2 plus
- Exhaust cam
- 39-41mm FCR Carb or '04-'05 450R Carb (cheap)
- Big bore kit w/high comp piston (Athena, Lukes, etc..)

You can choose stage 3 or stage 4 depending on your power requirements. Items in stage 1 & 2 should be installed before items in stage 3 or 4. It doesn't hurt to put the exhaust cam in at the same time you do the intake cam but you will get the most benefit from the exhaust cam with a big bore. Prices are approximate and do not include labor. Also, you can save a lot of coin by buying used stuff from reputable members on this forum.

For the carb...are you meaning Honda 450R carb or the Suzuki LTR carb? Just curious for my own knowing and in case I ever decide to go this route!

Honda 450R carb. It would be a big project to get the LTR fuel injection system on a Z though it would be very cool

Duh!!!! Im sorry! If I woulda been paying at least somewhat some attention to that, I wouldnt have even set myself up for that dumb question! Just been alot of late nights lately and some major carb probs with some jetting and needles on my end! So basically I have had Carb on the mind the past week non stop trying to resolve these issues! Thanks for replying back! Sorry for asking something so stupid and obvious! Its funny cuz I was just over at the shop looking at the LTR's not even 2 months ago and seen everything about it and read everything on it! Now if that stuff would just stay in my head where its suppose to! LOL!

Hello, I am the new guy on the track. Recently bought a z400 and love it !! I would like some opinions of you fellow riders on what is the best tire for the trails and track with out costing an arm or so. Also after reading all about everyones hop up kits. Is this stage 2 mod kit by Mods 3 a good set up or is it a waste of time and money. Here is the link for this set up and others that I found for the Z400. http://www.partsforatvs.com/default.asp?p=...=M3Q+Z400+POWER

Anyones help would be a great help. Thanks and happy holidays to all.

I think it would be a good kit if it came with a full exhaust instead of just a silencer... The real power is in the headder when it comes to exhaust!

Sorry but i'm going to jump back to the first page.

Do you think a 41mm fcr is TOO big? Just wondering what differences between the 39-40 are. I have a 440 with both hotcams and pro circuit t-4 full exhaust. The last thing i would really want to do is add an fcr, might as well do it already.

hello, i recently purchased a 2003 z400 and it is all good besides one problem i have been having while driving it, the guy told me he put some jets in it but wasnt sure what ones the place put in for him, i am guessing mabye stage 1 or something, he said it wasnt aftermarket, and it has a k&n filter (which i cleaned and recharged the other day), and i took it out driving the other day and it seems at high throttle like between 3/4-4/4 the thing is missing or bogging out and then i shift gears and it kicks back in, now i read the FAQ on adjusting the needle jet clip and by the sounds of it thats my problem, but i figured i would ask to see what you all thought about it, umm today i changed the spark plug and the old one came out black, i also dumped the old gas as the bike had not been driven for almost a year and i put in high test with some carb cleaner, but it still seems to stumble at full throttle at high rpms, so if you guys could mabye help me out with this and let me know if the needle jet clip is indeed the problem that would be excellent and very helpful and appreciated!


Thanks, Jordan!

ok so i just went out and tried to adjust the needle and i apparently seem to have a stock one as there is only one position, so i am wondering mabye he changed the jets but not the needle unless a jet kit doesnt come with one, either way i think too much fuel is getting in, but if someone could mabye help me out that would be awsome! and sorry if i am writting soo much, its just i am new to this bike and dont know much about it, so having this problem on a bike i just bought is kinda irratating to me, so all help is appreciated!

thanks, jordan

I'm new to forums so if I screw this up please give me directions on proper use. Thanks.

Can someone help me with the following. I just installed the Trail Tech Vapor computer on my Z400 and I am having trouble locating some tech specifics.

1. Ignition Pulses per Revolution or (PPR). Select from 0.5, 1.0, or 2.0 PPR. Does the PPR change over a certaing RPM? What is the RPM and what is the PPR at that change?

2. Engine Temperature. (A) What would be the high temp warning point (in F)? Default is set to 190 F, but I'm guessing it should be around 220 F. (B) What would be the over temp danger point (in F)? default here is set to 230 F, but again I'm guessing more likely it will be around 240 F.

3. RPM shift points. What would be the factory recommended RPM shift point (6,000 RPM)? What is the factory RPM over shift point (10,000 RPM?). Or since I have done performance mods, should this be subjective to performance of the machine and my read on engine characteristics?

Also, has anyone else installed the Vapor on their Z400? How did you do the magnet installation to the rotor for the speed sensor. On my 2006 the magnetic bolt would not clear the caliper so my only alternatives are to drill the rotor for a little spacing or just simply JB Weld it to the rotor...again if that will clear the caliper.

I'm looking to replace my stock front shocks on my 03 ltz400.
Which is better 05-07 LTZ400 OEs or TRX450R OEs ?

whichever one you can get a better deal on. they are about the same performance wise I think. I'm running '06 R shocks.

I was wondering if anyone could give me some recommendations, suggestions, and-or techniques of how to properly rejet my 06 KFX 400. I just bought a dynojet jet kit that comes with a stage one and a stage two. Here is my set-up:

Carb: 37 mm Mikuni (stock)
Airbox mods: stock box with Velocity airfilter and Outerwears lid
CDI: Procom non-adjustable with 2 degree timing advance and +1000 rpms
Location: southern Virginia at 300 feet above sea level
Exhaust: stock with free-flow tip
Other mods: Procom rectifier, Procom magic box, CRT performance temperature sensor

Any help would be greatly appreciated.
Thanks, Aaron

I am planning on doing the athena 434 kit, 40mm fcr, hotcam intake cam, and the DRZe kit without porting. My question is how does this set up fare compared to raptors and 450s in a straight line and overall feel...$1500 dollars would also make a nice down payment. I don't race just trail ride but want to go faster. P.S. already have the proflow k&n filter, k&n air box lid, and a ct racing exhaust. thanks

add to that stainless valves, trailtech flywheel, and dyna cdi and it will rip

I have a 04 dvx 400 and just bought a HMF bill ballance full pipe and i have a k&n intake i am planning on running with out an air box lid the carb is stock mikuni, but can anyone help with some jetting all i do is trail ride (exhaust sounds bad***) thanks.

have you changed anything in carb? try 165 main

nope shes just stock and im about 600 ft above sea level if that changes anything will it hurt anything if i dont jet it just for this weekend thanks.

had a question where can you get ajustable fuel screw? i went to dealership and they couldent find one for me so anybody know? for stock carb

anybody? ebay? cant find it anywhere

advantagecyclelc.com

JUST INSTALLED A DIRT DIGGER CLUTCH PACK IN MY 04 Z.WONDERING WHY IF I PUT A LITTLE PLAY IN CABLE CLUTCH WILL NOT RELEASE FULLING.(HARD TO GET IN NEUTRAL).IF I TAKE ALL PLAY AND PUT A BIT MORE TENSION AND CABLE IT WORKS FINE.ANYONE HAVE THIS PROBLEM?

Can someone help?? I need to change my axle bearings and have no clue how to get my axle apart...What do i need to take off and what side does it come out??

Thank

What years of the stock carb will work on a 2003 Z400?
I know the newer z400's carbs. have tps do they work on older z400's that don't have the tps?