Help Needed - Stubborn Girl

Ok,

I have rebuilt this 2000 WR400F.

Link is here: http://www.thumpertalk.com/forum/showthread.php?t=981792

During the rebuild I did the following modifications that "could" effect her willingness to fire up.

- JD Jetting Kit

- Baja Designs SuperMoto Kit with Headlight and Taillight (Also using their switch, wiring and kill switch)

- Changed all fluids

- Installed a new spark plug

- Installed full FMF Q4 pipes

- New UNI Air Filter

The bike is getting spark. Confirmed that twice today. The bike is also getting fuel in the lower float bowl as I removed the drain bolt and a hefty amount drained.

I have kicked for the past two days to no avail. I have tried clearing with the decomp cable pulled in and several kicks. I have also tried with the choke on and off. I am getting the motor to TDC and decomp to release and then back up top for a full stroke kick. Being a big boy with muscular thighs, I don't think it's a lack of power going through the kicker.

Please help. I am at my wits end and can't get it off my mind on what could be wrong and or indifferent to cause this issue. Any help, tips, or ideas are widely accepted and appreciated.

Thank you so much in advance for your help.

Ok,

I have rebuilt this 2000 WR400F.

Link is here: http://www.thumpertalk.com/forum/showthread.php?t=981792

During the rebuild I did the following modifications that "could" effect her willingness to fire up.

- JD Jetting Kit

- Baja Designs SuperMoto Kit with Headlight and Taillight (Also using their switch, wiring and kill switch)

- Changed all fluids

- Installed a new spark plug

- Installed full FMF Q4 pipes

- New UNI Air Filter

The bike is getting spark. Confirmed that twice today. The bike is also getting fuel in the lower float bowl as I removed the drain bolt and a hefty amount drained.

I have kicked for the past two days to no avail. I have tried clearing with the decomp cable pulled in and several kicks. I have also tried with the choke on and off. I am getting the motor to TDC and decomp to release and then back up top for a full stroke kick. Being a big boy with muscular thighs, I don't think it's a lack of power going through the kicker.

Please help. I am at my wits end and can't get it off my mind on what could be wrong and or indifferent to cause this issue. Any help, tips, or ideas are widely accepted and appreciated.

Thank you so much in advance for your help.

Common issues for bad/hard starting:

- Slide plate installed upside down

- Fuel screw has missing o-ring, or old o-ring stuck up there

- Pilot jet is clogged

- Hot start is leaking or stuck open

- Weak spark (should be blue/white in pitch dark) from bad harness mods

If you flood the motor it will take 20 kicks with the throttle held wide open, the kill button on, to clear it. More if you have flooded it over and over.

You need to set the fuel screw 1.5 turns, and try and tow start it.

An engine only needs 4 things to run. Air/Fuel/Compression/ & a proper timed spark. Even if your jetting is way off, it should still fire up. Have you verified that the sparkplug was getting wet with fuel? A little dose of fuel thru the sparkplug hole, and then re-install the sparkplug, does it at least try to fire? Maniac

take your hand off the throttle? my 98 wr 400 starting technique was ice cold (below 50) choke on 2 pumps of the throttle, roll thru the kicker twice with compresion release squeezed, tdc one more throttle pump and healthy boot........ normal cold choke on cycle thru kicker twice , tdc, healthy boot . warm no choke, tdc, healthy boot. hot or dropped the bike hot start pulled , cycle twice, tdc , healthy boot

all with my hand resting on the front brake master cylinder.... if I set my hand on the throttle it would not start since I was twisting it as I kicked

Thank you all for the ideas.

I will try each of these out and check on the carb build but I am 99% confident that it was built correctly. I am calling Baja Designs today and am going to run through the wiriing diagram and see if there is any issues that may cause the problem, if no, then I am canceling out electrical for good as it is for sure getting spark.

You mentioned you rebuilt it. Does that mean you had the engine apart? If so, have another set of experienced eyes look at the mechanical timing to make sure it is correct. Some bikes one tooth off will run, some will not.

The engine was rebuilt by a shop in Temecula and the bike fired up before the rebuild so I am in belief that she should just run... :smirk:

Thank you all for the ideas.

I will try each of these out and check on the carb build but I am 99% confident that it was built correctly. I am calling Baja Designs today and am going to run through the wiriing diagram and see if there is any issues that may cause the problem, if no, then I am canceling out electrical for good as it is for sure getting spark.

It shouldn't be the BD kit. The regulator/isolator that comes in the kit separates the lighting system.

It shouldn't be the BD kit. The regulator/isolator that comes in the kit separates the lighting system.

Just got off the phone with Diego at BD and he is confident that all my wiring looks good and since the bike is getting spark, i can cancel out the electrical as a culprit of it not starting.

Sigh.

Verify:

Carburetor slide plate installation(this should be new on a 400 rebuild since they break)

Verify precise camshaft installation since this has been the source of many no starts.

I must admit that when my 426 was brand new I had to tow it behind the truck to start it but it started much better after a few laps around the block.

cam timing?:smirk:

cam timing?:smirk:

The bike started before I rebuilt it and in the rebuild, I didn't crack the case of do anything internal on the motor so it should just fire! Grr!

Did the cylinder head need to come off at any point or cam shafts out for any reason? If so see previous posts, if not, your problem is most likely the carburetor. (fuel or lack there of) Turn the throttle two or three times and kick. If no start, check the plug to see if it is wet with fuel. If not, add a few cc's of fuel to cylinder replace the plug and try again.

I don't know what the equivalent is here in the US but in the UK you can buy an aerosol called East Start which you spray into the intake while trying to start, if the ignition is good you should get something happening.

Ether! AKA starting fluid. Have spray a little in the airbox and let her rip.

Ether! AKA starting fluid. Have spray a little in the airbox and let her rip.

Be careful with this method! It can be done, but too much ether will cause an explosion in the combustion chamber that can destroy the engine. This would be my last resort for sure.

I think you have a better chance of getting it started by bump starting it on a hill or pull starting it with a vehicle. If that does not work, maybe spray a little ether on a rag and have someone hold it near the air intake while you try to kick start the bike. If it starts, or acts like it tries to start, you know your problem is directly related to the fuel system.

From reading about your starting issue in both threads, it sounds like you had a shop open the engine and rebuild it. And it also sounds like you have verified your ignition and fuel are working. In my mind that means it has to be something in the engine. If it were my bike and I paid money to get the engine rebuilt, I would take the bike to the shop and show them it won't start. I would show them that you have ignition and fuel, and then hope they would agree to open the engine back up and double check their work. Just my 2 cents.

I think that he's mentioned that the engine ran fine after the engine work was done.

He rebuilt the rest of the bike, but left the engine alone as it was recently overhauled and ran fine.

Now, for whatever reason, the bike does not want to start. There is nothing wrong with the engine.

Edited by zlathim

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