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Kot

WR400F experts, need help, please

15 posts in this topic

Hi everybody!

My friend just bought '00 WR400F from Japan. We have a hell of a time firing it with the kickstart. Compression seems to be so high, we actually have to jump on the kickstart. As result, we broke the kick shaft :)

I know this might been an old issue, as we all now have 450's but does anyone had the similar problem with WR400F those days and how to fix the compression for easier start??? We all run on 95 octane gas here!

Please reply if there were any solutions developed!

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Kot, there should be a manual de-compression release. It is a little black lever usually located on the left side of the handle bar. Pull it in and push the kick starter through the stroke then, release the de-compression lever and give it a good kick. Should fire up in only a few kicks using this method. If the bike is new, it will start easier after break-in. Practice using the de-compression lever. Once you get the hang of it, it really is quite easy. Try this and, if you have any further questions feel free to ask. We are here to help.

:)

Paul

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did he use the manual de-compression lever on the handlebars?

These bikes should kick as easy as the new 450's, as long as you use the decompression lever.

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Thank you Paul and Kevin. I am going to practice with de-compression lever tonight, after work and will let you know results. We seem to do the same thing, but in a different way: Pulling the de-co lever - pushing the kickstart all the way down, kickstart goes up, release the lever and then kick from the top. I will try your way now and we'll see if this is the solution...

Thanks a lot friends!!!

Oh, one more thing... spark plug burns all the time. First thought - bad gas, but I run on it fine on my WR450F, seems like the problem with the jetting. If there are any ideas, please share.

Thank you very much indeed from FAR EAST RUSSIA!

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Riding Tips from Motocross Action Magazine

FOOLPROOF STARTING TIPS FOR YZ-F OWNERS

There is no doubt that the Yamaha YZ-F will encourage lots of new riders into the four-stroke fold. The rite of passage for any neophyte four-stroke rider is starting one of the beasts. The golden rule--tattoo this on your forehead is: "Thou shall not touch the throttle at any time during the starting process."

If you are smart, you will do exactly what we tell you. If you’re not smart...good luck.

Step one: With the transmission in neutral, turn the gas on and pull the choke out.

Step two: Kick the engine through slowly until you come to the hard spot (where the kickstarter will not move). This is called "bringing it up on compression."

Step three: Once you have brought it up on compression, follow these three steps: (1) Pull the compression release in. (2) Move the kickstarter about one inch past compression. Do not move the kickstarter so far that the piston goes through compression and moves too far down into its intake stroke. A little dab will do ya. (3) Once you have nudged the piston over top dead center, allow the kickstarter to return to the top of its arc.

Step four: Release the compression release.

Step five: Kick with a steady but full stroke (from the top of the kickstarter’s arc all the way until the kickstarter hits the footpeg). If you did everything as prescribed, the YZ-F will start. However, if you touched the throttle, it will not.

Throttle tip: instead of holding onto the throttle with your right hand, hold onto the brake master cylinder.

Hot starting tip: Pull the hot start button out and follow steps one through five. Push the hot start button in as soon as the engine starts.

Cold start tip: Before you start the YZ-F for the first time, give the throttle two little blips. This will put a small dose of fuel into the top-end. No more than two blips. Never blip the throttle before starting a hot or warm engine.

Enemy tip: If you don’t own a YZ-F but want to ruin the day of a YZ-F rider who you don’t particularly like, go over to his unstarted YZ and give the throttle four or five healthy twists. The accelerator pump will fill the engine with fuel and it won’t start until the following Thursday.

The word: The Yamaha YZ-F isn’t the easiest starting full-size four-stroke engine made--that honor goes to the KTM 520SX or anything with an electric starter, but the YZ-F will start every time--if you follow the drill.

As for your spark plug question, do you mean the sparkplug is fouling out >> and you have to replace it?

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We seem to do the same thing, but in a different way: Pulling the de-co lever - pushing the kickstart all the way down, kickstart goes up, release the lever and then kick from the top.

Ok, guys I dont want to complicate things for Kot, but once he pulls the decomp lever in shouldnt he only push the kickstart lever just past TDC (top dead center) not all the way through?

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"Ok, guys I dont want to complicate things for Kot, but once he pulls the decomp lever in shouldnt he only push the kickstart lever just past TDC (top dead center) not all the way through?"

Oh god, now you've gone and done it! Total confusion! :)

Actually, I think you are right. Does step 3 in Kevin's instructions above address your point? It is one of those things that I do without having to think about it much less try to explain. :D

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Oh crap. Now me embarrassed! :D

I cant read anything if its over 2 paragraphs! :D

Kevin made me exhert myself so much trying to get the VHS tape open he sent me, I lost all the blood going to me brain! :D

sorry.... :)

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cold: gas on, choke out. 1 turn of throttle. push the kick lever steadily down until it gets hard. Let kick lever come back all the way to the top. pull in decomp lever (left side above clutch) and hold. move the kick lever 1/4 kick down and return to top. release decomp lever. now you're ready to kick the beast. 1 long stong kick straight at the ground (this ain't no 2-stroke). should bring it to life.

if its warm, no choke, no turn of the throttle. If you've just dumped it, and are smelling gas, use the hot start (located on the left side of the bike-red nob) This is the only time i use the hot start nob.

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The ultimate fix, Kot, is to install a YZ450 exhaust cam with automatic decompression. There is lots of information here on TT regarding exactly how to do that and many of us have. It will start as easily as any 450 then without the "four-stroke starting drill". :)

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Guys!!

Thank you all a lot! We pretty much followed "step by Step" procedure and seems like the problem is gone now. The major issue was pushing the kickstart all the way down, instead of just one inch past the top end with de-co pulled. We got that fixed! Thank you very much guys :)

WR400+ series are great bikes when you know all the drills :D

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The ultimate fix, Kot, is to install a YZ450 exhaust cam with automatic decompression.

Will it fit WR400F 2000? :) If so, can anyone give me the P/Ns for parts required to do this mod? Appreciate your input :D

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This post brings back memories of looking for the nearest cliff to chuck this hard-starting POS off....jesus, why did I get rid of the DR350 with the magic button? The Blue Machine starts in 2 kicks cold or 1 kick warm every time now, even after a spill! Just burn the routine into your psyche and you'll be rollin' in no time :)

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can anyone give me the P/Ns for parts required to do this mod? Appreciate your input :)

5TA-12180-00-00 CAMSHAFT ASSY 2 $140.72

You WILL also need to re-shim the exhaust valves after you install the new cam shaft.

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