Need help ASAP!

5 replies to this topic
  • Guest_Guest_*

Posted February 10, 2001 - 10:39 PM


I'm the owner of a 2000 WR400 and have owned Yamaha motorcycles for ever. I bought this bike since I wanted to get back into a 4 stroke unit after I sold my YZ250. My problem is that I found this website after the ad was placed for my bike which goes up for sale this Tuesday. I'm selling it since I have't been satisfied with the power of this bike, and if the bike is stalled when first starting it, it is a bear to get started again.

Please help me before I have to sell it and go to a KTM 300MSC.

(1) I understand that there are 3 restrictors
in my bike and how do I take these out and how much more power will this give me. I have had a problem getting the front tire to come off the ground in second and third gear and.

(2) Why is this bike so hard to start after it stalls in the initial start-up stage, and what can I do to prevent this.

If you want to E-mail @ me or leave your # I will call anyone who can help.

**Note: I'm registered for this site but had problems with my password.

  • tripm

Posted February 10, 2001 - 10:57 PM


1. Remove the throttle stop:

2. Pull the plug out of the end of your exhaust can. One bolt (10mm?) and the plug comes out.

3. Either remove the entire top of the airbox or just the snorkle.

About .5 - 1 hours work.


  • tripm

Posted February 10, 2001 - 10:58 PM


Oh yeah, #2. Don't touch the throttle when you start it. I actually put my hand on the bars so the throttle doesn't move at all.


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  • Michael

Posted February 10, 2001 - 11:10 AM


Check the history using the search function. In short, there is a throttle stops that limits the throttle to about 60% open. Replace it with one off a YZ, or grind it down to a full WOT and you will see a huge improvement! Remove the exhaust baffle - its easy and your search will show the details if you need it. Remove the plate in the top of the airbox and throw it away or modify it to be a prefilter (again a search will show what has been done).

If your main problem with the bike is lack of power - this will make you grin. I can launch the front wheel with throttle only at 35 mph in third gear.

Starting after a stall - solution is not to stall :). There are lots of tricks - biggest one is to remember you have a pumper carb, and don't open the throttle at all. If it doesn't start after a kick or two (using the hot start button) I shut the gas off and lay it down (clears the float bowl - don't know if that really helps but I do it cause I've always done it) using the compression release and kick it through a couple strokes. Gas on and kick it with authority (using the hot start). I don't have much of a starting problem....but I used to ride a TT500.......

Don't sell it until you do those three things. If you still decide to trade for a KTM - at least make it a 400 or 520EXC (eletric start you know)

  • Bill

Posted February 10, 2001 - 11:10 AM



Your bike should not be down on power compared to the 250 and if you like the 2-stroke type power band, you can change the valve timing to be the same as the YZ400f.

As far as restictors. You have the airbox lid, the throttle stop and the exhaust baffle. Once you remove these, the change will be huge, with the throttle stop being the biggest change. Your bike is only getting about 5/8ths throttle right now. Can you imagine the difference having almost a half more throttle :).

As far as hard to start after stalling. Start the bike with the choke on and after about 15-30 seconds push the choke in and let it idle for 5-15 minutes. It's hard for me to say since I don't know the temperature of where you live.

You have to know that the bike in YZ configuration, is competitive in the 250 class. So you do have a very fast bike. It just sounds like it needs some fine tuning. You can find out how to change the valve timing to YZ by going to the "tech" section of this website. It will provide step-by-step instructions on how to do it. It will only take an afternoon and can be done with simple tools. I have not done this change and my bike pulls my buddies new ATK 250.

Don't give up without first tapping into the power you have not found yet.

If you'd like, give me a call xxx-xxx-xxxx

86TT225, 99WR, WR timing, throttle stop trimmed, air box lid removed, White Bros head pipe, silencer and air filter. Odometer and headlight removed. Moose hand and mud guards. YZ stock tank and IMS seat. Renthal Jimmy Button "highs" and Renthal Soft half waffle grips. AMA, SETRA.

[This message has been edited by Bill (edited 02-10-2001).]

  • bonez34

Posted February 10, 2001 - 04:01 PM




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