Running Hot - Won't Start

Yesterday I rode a creek bed for 6 miles. It took 6 hours. First gear only stuff.

I had the following problem that maybe someone can help me with.

A week ago I rode another technical area and found myself stalling it alot(more than normal). It was very hard to start, which is unusual for this bike (1-2 kicks normally). So I changed the plug and cleaned the air filter hoping that would fix it. Cold the bike starts first kick everytime.

Assuming I fixed it I started up this creek bed yesterday morning. I found the bike stalling alot again and extremely hard to start. I tried flushing it, hot start out, hot start in. The only thing consistent was letting it cool down.

Then 1st kick it would start.

At one point the bike actually spewed steam underneath the engine, filled the reservior with coolant, then after 5 minutes sucked the coolant back in the radiator or block.

Some have told me the WR426 wasn't meant for a lot of 1st technical stuff. It needs airflow. I can't believe that, or should I? I'm thinking water pump or radiator cap spring.

What do you think?

Thanks for your help.


PS I'm covered in poison oak to boot. But it was still fun!

When I first got my WR426, I started it and let it idle for like 15 minutes while I was removing the warning stickers off of the fenders. Meanwhile, it was leaving a puddle of coolant on the ground. I called the dealership and the guy said that the bike heats up very quickly and needs good constant airflow. The radiators alone cannot keep it cool, there is no fan, so it must be moving!

... and the day after I got mine home it's idling in the driveway, I go 'round front cause one of my friends had pulled up. I tell him my wife had bought me the bike I was talking about. "Let me go show you how cool it is!" "It's in the back. Come see! Come see!" I say, as I eagerly lead him towards the drive...

He says "Is it s'posed to be smokin' like that?" :)

[ March 10, 2002: Message edited by: midlifecrisis426 ]


give me your PJ/PAJ and needle code.

to get this situation corrected you need a lower letter needle straight. this will allow a slightly richer closed throttle condition.


let me know.


Thanks for the help.

Taffy, My carburator is stock. I haven't change anything. It was always running fine. Should I try turning my pilot screw out?

Justin and MidLife, Do you have the overheating problem on tight trail rides??




I guess my needle code is OBDRR. I think?



that tells me everything, ta!

the width of your needle is the third letter. the later the letter the wider the needle/leaner it runs.

they used to come with 'M's in 98/99 then they went to 'P' and 'Q'. 'R' is awful.

get a N427-OCDMM. if you go to WR timing get the N427-OCEMM. the difference is that one needle (D) is at .75 degrees while the 'E' needle is at 1 degree.

a hot runner would be the following

lid off, throttle stop chopped, grey wire done, deoctopus (98/99) WB filter, fairly open pipe (vortip/WB/FMF etc).

160MAJ, 165 MJ, DMM needle, clip 2, 35PJ, 45 PAJ screw, 60 SJ, do the taff mod to your APJ and do it to .024".

this needle (the D)will have less/no hesitation compared to the 'E' series so snap wheelies and bottom end stomp will be better than the E. there is a chance that yopu will be a little rich off idle but i don't think so.

there would be two cures for this. 1) DMN needle 2) go to 55 on the pilot air screw.

someone is running the DMM over here and loves it.


:) I'll back Taff up on his theory of the DMM...I'm running it and what a differance from stock!, Snap 3rd gear, no problem , good economy Try his set won't be dissapointed! :D

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