'02 WR426 starting problems
Posted February 11, 2010 - 07:59 AM
I cleaned the carb, all jets clear, AP squirt good, good fuel delivery. New plug in, gapped appropriately, old plug still in great shape, and getting spark.
Kicked for hours with only one fire. Usual start-up routine. I notice it's much more difficult than before to find TDC. Bump starting unsuccessful, because it also seems the clutch is not releasing, and I'm at the max of adjustment.
This week and next I'm looking to check the cam timing and valves, and possibly replace the clutch, and do the auto decomp exhaust cam (Hotcam or '03 YZ450???).
Model/Year: 2002 WR 426
Engine: Stainless steel oil filter, Notoil Air Filter
Carb: White Bro. fuel screw 1 3/4 turns, MJ 162, PJ 42
Exhaust: Jardine RT4 Can and Mid, FMF PB SS header
Fluids: Maxima 10-40 4 stroke
Chassis: Applied clamps, Protaper 1 1/8
Protection: Devol skid, radiator, frame protection, Acerbis Rally2 bark busters
Electrical: Grey wire, Vapor Trailtech
Cosmetic: IMS 4.0 Desert Tank
Miscellaneous: Altitude 3500-8500 MSL, Temps 20-60 F (Winter)
Ideas, solutions, guidance....???? What clutch is suggested besides Rekluse? HotCam or YZ cam???
P.S: Should I go ahead and do a Wisco piston upgrade while I've got it apart? Also which gasket kits are best when removing the head as this is my first time since the late 80's I've done any severe engine work. I'm also planning to sell this beast once she fires and runs worthwhile.
Posted February 14, 2010 - 08:47 AM
It could be worth while changing or a good clean of the pilot jet. Also check the kill switch and the grounds on the frame to make sure. Also my old 426 cracked a plug cap and was a pain to fire up. Has for the cam you may be better off with yz auto cam than the hot cam my 426 was a pig to set up with the hot cam and wouldn't run right so i went to old yamaha cam and no more hassle. Ive also used EBC clutches in all my yamaha's with out a problem and they last a long time hope this helps.
Posted February 14, 2010 - 07:03 PM
If your timing is okay, then spray use some starter. This will help determine if the problem is with fuel or spark.
Posted February 14, 2010 - 07:18 PM
Posted February 16, 2010 - 06:41 AM
Sorry for the derailment. It had to be done.
On a serious note, if you are kicking it repeatedly and getting nothing, it is usually fuel or fire. It appears you have cleaned/checked most of the typical culprits. Is it possible that your fuel line is clogged? Or maybe your choke is stuck? Just trying to think of something simple that is out-of-the-ordinary before you tear it down. I just fixed a stuck float problem, but it sounds like you have already cleaned the carb.
Posted February 16, 2010 - 09:17 AM
It may be some time for me to get it figured out, as wifey has made the taxes a priority for me.
Posted March 18, 2010 - 06:31 AM
The issue: I had inverted the order on the needle spring during my first carb check in Novemebr. Spring washer, Spring, needle, needle nut. I replaced everything in the right order, and she fired up, but jetting was bothersome. Replaced 40 PJ with 38 PJ and she runs like a champ.
Also, the cap gasket to my IMS tank degraded and fell into my tank. Had to filter the fuel and flush out the tank. What a pain.
Still might consider an '03 Auto-decomp cam, but I'm considering selling to get an 08 or 09 WR. Finances will tell.
Model (400 - 426 - 450): 426
Cam Timing (WR/YZ): YZ
Main jet: 168
Pilot Jet: 38
Leak Jet: N/A
Starter Jet: 65
Fuel screw (turns out): White Bros. 1 3/4 out
Needle Model/Clip position: Stock needle in clip 4
Grey Wire Mod (Y/N): Y
TPS Connected (Y/N): Y
Airbox Snorkel/Lid (on or off): Lid off
AIS Removed (Y/N): N/A
Airfilter Brand: NoToil
Exhaust Brand: Jardine RT4 w/Jardine mid-pipe, FMF Powerbomb SS Header
Average Altitude: 3500-7000 MSL
Average Temperature: 70
Average Humidity: 7-18%
Degree of Satisfaction (0-10): 8
Still need magic button!!!
Thanks for the help in correcting my stupidity. It's all in the details...
Posted March 18, 2010 - 08:12 AM
Posted March 19, 2010 - 06:59 AM
I took it out for the first ride today. Got 3 miles from the truck and noticed my idle was hanging at 4000-5000 RPM. The idle screw wouldn't turn at all. Rode back down 2000ft drop at white knuckle speed, but at least I didn't boil out.
When I got home, a quick spray of CRC 6-56 on the idle screw and throttle linkage, a little adjusting, and perfection.
Again, it's all in the details.