wr426 starting / timing issue
Posted June 03, 2013 - 03:26 PM
This bike has been modified before I bought it. Exhaust cam was set forward 1 pin.
A blue wire is severed also. It ran, but owner always had it warmed up before I got to his house.
I haven't been.able to start it. I also reset the timing.
( chains have slipped since, so there is no way to get back to original teeth.). It backfires when we try using starting fluid in the air box. The boot also gets hot while trying to kick start.
I've moved both teeth forward 1 pin from shown location with no better luck...
Posted June 03, 2013 - 07:05 PM
Backfiring = Too much fuel
What is your starting proceedure ?.....
NEVER EVER turn the throttle when kicking. FCR carb will flood cylinder and cause a big backfire.
ALWAYS kick from just past TDC in compression stroke with one hard kick. Any other method will just stuff your ankle or the kickstart shaft (unless it has Auto Decomp cam).
If jetting is correct it should start in 3 kicks max. (with Choke when cold)
You need to confirm your carb jetting to be sure. Otherwise you will just go in circles.
The manual will tell you the stock Pilot, Float and Needle settings. Start there. Also make sure your idle screw isn't turned up too far (which often masks jetting issues)
post back if you need help
Posted June 03, 2013 - 07:31 PM
Posted June 03, 2013 - 08:01 PM
With a CLEAN carb....
Here is a starting point
Pilot jet (42)
Pilot Air Jet (75)
Fuel screw (1.5 turns out from bottom)
Main Jet (165)
Main Air Jet (200)
Needle model and clip position (OBDRR #4)
Posted June 03, 2013 - 09:10 PM
Posted June 04, 2013 - 08:43 AM
Only.time it backfired is when.I.use a starting.fluid.
It.backfires through the air box.
Cams are set as shown in photo.
Jets are stock as far as I know.
Carb is clean and clear. Just checked.
New spark plug.
Posted June 04, 2013 - 09:03 AM
Open choke (cold)
Set kick to compression stroke
Go to step four and repeat
Posted June 04, 2013 - 04:56 PM
Posted June 04, 2013 - 05:22 PM
Does it go right through to outside?
Posted June 04, 2013 - 06:22 PM
Posted June 04, 2013 - 06:32 PM
I would remove the Pilot, Main, PAJ, MAJ, Starter Jet and soak them in Carb Cleaner.
Set needle to #3 clip
Remove fuel screw and check O-Ring, then reset to 1+1/2 turns from bottom.
Make sure slide plate valve isn't upside-down (often stuffed up and causes all sorts of strange results).
Make sure Idle screw is only lifting slide by a couple of mm.
Re-assemble and try again.
Posted June 04, 2013 - 06:38 PM
The clip is currently set to #4. Which way is #3? Down 1 or up 1? That lowers or raises the needle?
Thanks for all the help... hope I'm not out of a bike. I just bought this thing.
Posted June 04, 2013 - 06:51 PM
You could try tow starting it and then see if it starts after that. My WR400 did it once. Had to tow it on tarmac to get it going and then never had a problem after.
Starter fluid is just hiding some other problem.
Posted June 07, 2013 - 08:21 PM
Posted June 08, 2013 - 02:34 AM
I found a pic of the upper bowl, using google, and that hole does not belong there.
Oh yes it does and should look just like you described it but it is not from corrosion...
Posted June 08, 2013 - 04:00 AM
Can't hurt to try.