New guy to dirtbikes with question.


9 replies to this topic
  • Colombo

Posted August 17, 2007 - 10:52 PM

#1

Hi all,

Sorry if this is short but I just spent 10 minutes writing a very detailed post about this and I lost it because I wasn't logged in and then I hit the wrong button and... :banghead:

So here goes the super shortened version:

1. Me = know absolutely nothing about dirt bikes.

2. Me... go test ride '01 WR426

3. Him... start bike 1-2 kicks (good). Let bike idle 30 seconds, takes it around the block, brings it back, turns it off. Let's it sit for a few minutes as we chat.

4. Me... go through convoluted (but apparently normal from what I've read here) starting procedure... hey it works 1st kick... great! :thumbsup:

5. Me... take it around block. Dies twice when coming to a stop with clutch pulled in. Also noticed that the idle hung high for a couple seconds when coming to a stop. Did not notice if choke was still on or not.

6. Me... mention to him stalling issues... he explains wr426 is very cold-blooded and it wasn't properly warmed up yet. I touch the engine head and it's warm, not hot. I specifically ask him if the carburation is well tuned... he says it's fine.

7. Me... remember that when he took it around the block didn't stall at all.

I'm concerned about the stalling, but is this possibly normal when it's still cold? Man I just feel like a fish out of water with these dirt bikes, street bikes are SO much easier.

Any advice or opinions would be greatly appreciated, either about this experience, or tips for me on future test rides.

Thanks!

  • fishpost19

Posted August 18, 2007 - 04:01 AM

#2

First of all, I know how you feel, losing your post after putting in so much effort. It's happened to me dozens of times. I sometimes go to the trouble of copying the post, and pasting it in if I lose it.

On to your question. Four strokes do not like throttle when cold. They have to be hot before they will accept input from your wrist. From what I read, I'd guess you're looking to purchase the bike, and the owner rode it before you. :excuseme:

My bike needs to be completely warmed up before I can rev it. It just bogs when I twist the throttle the slightest amount while cold. When slightly warm, it will hesitate, but throttle works. Four strokes don't like to idle when they're cold without choke.

If you keep the revs above the idle point while cold, it won't stall. When the engine is hot, it will idle fine though. So there you go, he probably just kept his revs up when it wasn't hot. Then you rode it, pulled in the clutch, let the throttle off, and it stalled coz it wasn't hot enough to idle properly. Don't be concerned. If it runs good when hot, all is good. If it stalls when it's cold at idle (normal), as well as hot (not normal), then you should look the other way. You shouldn't even ride bikes until they've completely heated up to operating temperature, but they're so tempting to ride straight after starting.

Hope this helps.

  • Colombo

Posted August 18, 2007 - 06:02 AM

#3

Yes that helps alot! It also confirms my suspicion that I should have kept riding it for a lot longer and judged it after it really warmed up. I'm just so used to my streetbike which needs less than a minute ( fuel injected of course ).

Live and learn... thanks!

  • mikewr450

Posted August 18, 2007 - 07:19 AM

#4

be sure to check the oil for metal flakes.

  • Just_a_trail_rider

Posted August 18, 2007 - 08:25 AM

#5

Since you know very little, why not take to a shop and have them check it out. I've done this before with street bikes and dirt bikes are even easier to check.

Never mind tires, brakes, chains or sprockets. Those are disposable items. Have someone look at the engine compression, check the timing chain for excessive noise/wear, basic operation of the suspension, engine oil condition and the cooling system.

Should take no more than an hour.

However, everyone I know with a wr426 still rides the snot out of them after 5 or 6 years of hard core racing. Does it have the decompression cam modification?

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  • Solo

Posted August 18, 2007 - 09:57 AM

#6

Does it have the decompression cam modification?


4. Me... go through convoluted (but apparently normal from what I've read here) starting procedure... hey it works 1st kick... great! :thumbsup:


I'd say no. :prof:

  • dr x

Posted August 19, 2007 - 06:22 AM

#7

First of all, I know how you feel, losing your post after putting in so much effort. It's happened to me dozens of times. I sometimes go to the trouble of copying the post, and pasting it in if I lose it.

On to your question. Four strokes do not like throttle when cold. They have to be hot before they will accept input from your wrist. From what I read, I'd guess you're looking to purchase the bike, and the owner rode it before you. :excuseme:

My bike needs to be completely warmed up before I can rev it. It just bogs when I twist the throttle the slightest amount while cold. When slightly warm, it will hesitate, but throttle works. Four strokes don't like to idle when they're cold without choke.

If you keep the revs above the idle point while cold, it won't stall. When the engine is hot, it will idle fine though. So there you go, he probably just kept his revs up when it wasn't hot. Then you rode it, pulled in the clutch, let the throttle off, and it stalled coz it wasn't hot enough to idle properly. Don't be concerned. If it runs good when hot, all is good. If it stalls when it's cold at idle (normal), as well as hot (not normal), then you should look the other way. You shouldn't even ride bikes until they've completely heated up to operating temperature, but they're so tempting to ride straight after starting.

Hope this helps.




Both my yz 426 and my wr 450 only need choke to start up, as soon as they are running i turn the choke off and can rev and leave to idle staight away, no bog, hesitation nothing....just start and ride!

  • woodsk

Posted August 19, 2007 - 09:08 AM

#8

I have both a 2000 400 and a 2004 450. each with JD jet kit and extensive jetting and fuel screw tuning.

They, with out a doubt have to be warmed up.

  • Colombo

Posted August 20, 2007 - 12:11 PM

#9

I'd say no. :prof:



I'm not positive but I don't think so. I had to use a second smaller lever by clutch while nudging the kick lever from TDC before I brought the lever back up top for the final kick to start.

If the decompression cam mod gets rid of this procedure even better! What year WRs did this start to become stock?

Thanks, Jose

  • SJMC_DON

Posted August 20, 2007 - 12:16 PM

#10

I'm not positive but I don't think so. I had to use a second smaller lever by clutch while nudging the kick lever from TDC before I brought the lever back up top for the final kick to start.

If the decompression cam mod gets rid of this procedure even better! What year WRs did this start to become stock?

Thanks, Jose


2003 I think, same year as the magic button...




 
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