2003 Yamaha Warrior 350 YFM350XR Issues

[calypsobikes]

Okay a while back, i had some issues with spark. And carb issues, all that is now taken care of, HOWEVER my quad was sitting for the last 8-10 months due to lack of funds. Now that I got it running, a new spark plug, ignition coil, stator, and voltage reg.

It starts up IMMEDIATELY now!! I installed an Oil Cooler Mod with the Hayden 401 Transmission cooler, and couple of Fragola 90 degree -06AN swivel fittings, 1/8th npt to -06AN adapters yadda yadda so on, so forth. I put 3.3 Quarts of Valvoline Racing 20w50 oil in it. The clutch seemed to be slipping (it was sitting for 8 months (or more) doing nothing). Once it got warm and the clutch got wet (hehe sounds dirty) it seemed to shift fine, so everything is good in that department.

Here is my question... I took the Stock Airbox off of it. I built an aluminum housing that holds my electronics and battery (some cutting of the plastics was done) and I'm running straight UNI Carb Filter and Crankcase Breather. It seems to be running lean at the current moment, do I need to re-jet the quad? Has anyone removed their stock airbox and run straight filter? If so what jet kit did you use? OR did you just adjust the pilot screw out (or in) to compensate for the lean fuel mixture?

One other thing, my Haynes Warrior manual is right next to me, I'm just to lazy to hunt down the illusive instructions as to which way to turn the pilot screw in order to make it more rich/lean, does anyone know which is which? Righty Tighty Richer, Left Loosey Leaner, or the other way around?

 

[tyler]

Ya your going to need to re jet it since your running no air box cuz it can breathe insanely great now and your getting more air so your going to need more fuel also, so all in all yes you will need to re jet it, what size jet are you running now? and your going to need to go up a size or two just depends on how it runs after you go up a notch or whatever your going to do.

 

[calypsobikes]

Currently its stock jets right now, I talked to the yamaha dealership guys and they said I might have to, i might not, depending on how much air its getting. One other problem I noticed today, is it smokes white smoke when it starts but once it gets warm (operating temperature) the smoke stops, should I be concerned? Could my piston rings be going bad?

Stock jets are as followed
Main Jet: 145
Main Air Jet: 0.6
Jet Needle: 5J18-3
Pilot: 42.5
Pilot Air Jet 1: 1.0
Pilot Air Jet 2: 0.7

 

[hawkster0001]

before you go jetting, try adjusting the needle, and the pilot wont change alot, just minor fine tuning, the needle can be adjusted by taking the top of the carb off (3 screws) and remove everything on the slide, take the needle, and put the circlip down one notch so it lifts the needle up higher when its sitting in the slide, and then you will be able to tell, if it idles fine, but pops on deceleration you can adjust it with the needle. and the smoke is probably just your vavle seals. rings would smoke constantly, before my rebuild mine use to be like a war fogger.

 

[hawkster0001]

in the carb:

 

[tyler]

If you have an aftermarket pipe then yes you WILL have to re jet it if you ever want it to run properly. And adjusting the needle will also help. and as for the white smoke on start up that is caused by your valve seals starting to go bad. What is happening is when the engine and all the metals inside the head cool off the metal shrinks and therefor the valve and seals dont line up correctly so oil drips past the seals and when it starts that smoke is actually the oil burning off but when it get to operating temperature the metal gets hot and expands and causes the seal and valve to make a perfect seal. I had this EXACT same problem and its not a problem until it smokes for about a minute or any longer.

 

[hawkster0001]

welll your just about right tyler, exept the valves seals are rubber, and get worn down over time from the valve moving so fast inside it, and if your quad has sat for a really long time, its possible the vlave sals are dry rotted, but kinda unlikely, there probably just worn, and the valve guides are metal.

 

[calypsobikes]

Stock Exhaust, the only things I have done to it, are mostly cosmetic, apart from the airbox being removed and running a straight UNI Carb Filter and UNI Crankcase Breather, that's it!

Nothing internally has been done to the engine since I got it about 12 months ago. It feels like a 350, so I know the previous owner didn't over bore or put a stroker in it. It was completely stock when I got it. I took the Airbox off and put some nerf bars from a yfz450 on it, OH YES THEY FIT, Had to do some custom cutting and welding. Had to cut my foot pegs off and weld some tubes and 3/8" flat plate onto the original foot peg mounts and move them back 1.5-1.75" so I have to shorten my brake pedal and shifter pedal by the same amount. Had to cut the aluminum mounting tabs off the 450 nerfs and re-weld them in the correct position. I will take some photos and upload them.

I made a custom 11 gauge aluminum electrical box where the airbox and battery box used to be, I cut my plastics into a more racier look! I am going to put 21x7-10 in the front and 20x10-9 in the rear, it will have the same setup as a yfz450 as far as tires.

I did the oil cooler mod at work, and put 3.3 quarts of 20w50 Valvoline racing oil in.

I made a custom wheelie bar so I don't screw up my next grab bar, like I did my first one. Only doing this while I learn how to do wheelies on my Warrior. This is my first power sports toy, and was never allowed to do it on others I have ridden, or they have been utility quads which lacked the ability to do wheelies, or just never tried. Now that I own my own, I don't care how I treat my quad.

I rebuilt a used carburetor, because in the old carb the pilot screw was frozen. I mean FROZEN! I tried so many things to try and get it fixed, much to my avail nothing worked. I found one on craisglist between 1993-2004, it was in decent condition. So i soaked it for 16 hours or so, and rewound the springs in the throttle linkage and all that fun stuff. I took the best from both carbs and got a rebuilt kit, and replaced all the o-rings and gaskets and stuff.

Gas has never just SAT in the carb, its been drained when ever I knew it was going to sit a little longer until I got it fixed.

I think that covers it.

Here are the pics...

Here is the box I made to house my electronics

Here is the wheelie bar

Here's the oil cooler mod and some of the work on the nerf bars like the mounting tabs.

Here are the Nerf Bars from a 2006 YFZ450

 

[hawkster0001]

wel that uni filter would make a big difference in flow allowing more air making oyu have to rejet it, and not to mention theres no airbox

 

[calypsobikes]

I know a lot can be told from the spark plug after use. So to help you to help me, I will give you everything you need to know to help me out easier/faster
So here are a few spark plug pics...

 

[calypsobikes]

IMHO I think it looks fouled with oil, a bit glossy. And considering the white smoke coming out of the motor, worn valve seals is the next thing i need to fix

 

[tyler]

Ya it for sure wont huirt to replace them but its not a big problem yet.

 

[cycygrace]

yeah and whats that stuff on ur thumb?

 

[buzzy613]

what color should the plug be? should it be grey and white?

 

[hawkster0001]

kid of a darker grey would be good, yours looks a little dark, but that would be normal for burning oil. heres mine, its a little on the lighter side, after adjusting my jetting for an open airbox (ran a bit lean before adjustments were made) and mine topend is basically all brand new and doesnt smoke, but any ways heres a pic.

 

[calypsobikes]

yeah and whats that stuff on ur thumb?

The stuff on my thumb is actually not stuff, we call that (in the industry) lack of focus, and being tired at work and running a .080" drill bit through your thumb, its not fun. Don't try it kids, it doesn't feel good!

 

[cycygrace]

ooooooooowwwwwwww thats sucks!

 

[tyler]

Haha dang that freakin sucks!

 

[calypso]

kid of a darker grey would be good, yours looks a little dark, but that would be normal for burning oil. heres mine, its a little on the lighter side, after adjusting my jetting for an open airbox (ran a bit lean before adjustments were made) and mine topend is basically all brand new and doesnt smoke, but any ways heres a pic.

What elevation are you at and what jet settings are you running? and position of the circlip on the main jet needle?