00 YZF 426 hot starting problem....

[tHEIF_oF_dREAMS]

Just got this bike used pretty hard, was raced hard. Not horrible shape. We have been messing with the tuning, Bike will start 1 to 3 kicks dead cold every time. run for a while stall or stop bike, 30 - 40 kicks min to re fire. Hot start, gas off tried many different combos. We did the Bk mod and we run race gas for the port and polish in the motor. When she fires, it a running machine. Tuned for desert in PHX, bout 1000 to 1200 ft. Plug seems fine, nice golden brown. Could the floats be flooding her? Ant help would be greatly appricated!

[brett_h]

What is your jetting?

[tHEIF_oF_dREAMS]

172 main, clip in center of needle ( 4th from top), 42 pilot, 1.5 to 1.75 tuns out (ish) on air screw. Bk mod bout .3 on the squirt. She will start cold with 3 kicks every time, after shes warm and you stall her, heartless beast. Thanks again for any help or light!

[tctrailrider]

Have you checked the valve clearance? When they get tight you will start hard. Your jetting seems about right. Also with the bike warm and running pull the hot start, this should cause the idle speed to increase and hang before dropping. Could be the hot start is not working.

[tHEIF_oF_dREAMS]

I will def check the hot start. Its after market thumb switch. What is or where may i find the valve clearanve spec for the YZF. i have a shop manual for the WR same year but i dont believe that they are the same.

Thx again.

[tctrailrider]

What is or where may i find the valve clearanve spec for the YZF. i have a shop manual for the WR same year but i dont believe that they are the same.

I had a 2000WR and am pretty sure the manual was for both WR and YZF. The cam timing is not the same but pretty sure the valve clearance is.

[brett_h]

I have the following jetting in my 00 426: 165 m.j. 45 p.j. needle #5.

[yamaboy23]

i run a 48 pilot jet with the leanest {the one with the longest plunger} accellerator diaphram and a 165 main jet

with that and the carb clean youll have no problems

[James_Dean]

tHEIF_oF_dREAMS,

After reading this post several times, the jetting looks good. Check your float level and lower it 1-2mm. Check your tank venting from the cap. Make sure it is not blocked along with the fuel line to the carb.

If there is anything suspect in the ignition wiring, sparkplug wire, cap, or sparkplug, check or replace them. A weak spark can be a symptom of faulty electrical when hot.

Check the valve clearance as suggested above.

Make sure you don't flood the engine by twisting the throttle when hot. Use a slightly fast idle speed and consider trying clip position #3 with a #168 main jet. The sparkplug is good, but the main jet is richer than most riders use, clip is typical but might be worn.

Hope the few extra ideas help-

James

[tHEIF_oF_dREAMS]

James, we will look at each of this as you listed them. We were running a 168 main but she was back firing on decel. I am not sure how to set the floats. clip 3, (from the top?)My partner thinks that the spark plug could be suspect, he is a 2-smoke fan and wants to change the plugs alot. I told him its a different beast all together. We also tried the blue wire cut ( per motoman393 )the valves are within wr specs. we did notice that if you turn the gas off and let it run for bout a minute then turn the bike off she will start again.

Thanks again for all the support with our problem.

T

[dave450wr]

Had a similar problem with my 03 426 would start like a dream cold.Sometimes when hot ( but not always ) I would spend a hour kicking the ---- out of it.1 day it took 5 of us an hour to start.I never did find out what caused it.Let us all know how you go.

Dave

[McGaber]

Sounds like your floatlevel is too high.

[tHEIF_oF_dREAMS]

What is the proper proceedure for setting floats. I have read of two ways but they seem to differ from each other. JD had mentioned that the level should be at 2-3 mm. Any help will be greatly apprciated.

thx again for the forum help!

[James_Dean]

No,no ?

I said LOWER the fuel level 1-2mm. The float bowl removed. Turn the carb so the floats just close the needle by having it about 30 degrees from upside-down. The float seam should be parallel to the bowl mating surface, and the bottom of the floats will be 8-10mm from the mating surface.

James

[tHEIF_oF_dREAMS]

James D, very sorry for the misunderstanding, and thank you very much for the clarification. we are performing the changes now and hope to get some test time in before the dune trip on Wednsday! Thank you JD and all forum members for helping us out!

T