Heelllpppp!!!!


19 replies to this topic
  • skin64

Posted August 02, 2010 - 09:01 AM

#1

Hi all. I'm new to this forum & need your help if poss. Just bought a 2002 WR426 from ebay (I can hear the groans already!). Turns out that 5th gear is shagged & it seems to be a bas#@%d to start when "warm". I can live with the 4 gears for now. I'll strip it during the winter & put it right.
It's this starting problem that really gets my goat. My right foot has a massive bruise underneath from kicking the tw@ttin' thing! - When it's cold, it'll start first or second kick, but if you ride it a couple of miles & switch off, it'll start straight away, but if you leave it for 10 minutes or so, it takes about half an hour before it'll start again!
I know it has the cold & hot starting chokes & I'm wondering if I've not mastered them yet..? - I'd be really grateful for any advice as I've already knackered one right training shoe, one right boot, two pairs of socks & one right foot!!

Cheers, Skin.

  • William1

Posted August 02, 2010 - 09:17 AM

#2

Check the float needle valve for leaks. There is a oring that often gets britle and dribbles fuel.

Check the pilot and fuel screw for being correct .
Fuel Screw/Pilot Jet
Fuel screw settings in the 'book' are recommended starting points. Every bike is different, as is the temp and altitude. Set the screw according to this method. Do it with the bike fully heated up.
Gently turn the screw all the way in. Now back it out two turns. Start the bike and fully warm it up, go for a 10 minute ride. Set the idle to speed to 1,500~1,800 RPM as best you can (I know, without a tach this is tough, just set it to were it idles relatively smoothly). Once warmed, slow the idle to the lowest possible speed.
*** When turning the fuel screw, keep an accurate 'count' of the amount you are turning it and record it in case you have to reset it for some reason. Makes life easier when you can just set it from notes Vs. going through the procedure again.***
Turn the screw in until the idle becomes rough or the bike stalls.
if it stalled, open the screw about 1/4 more turn. Restart it and slowly screw it in till you can just perceive a change.
If the screw can be turned all the way in and the bike still idles perfectly and does not stall, then you need to go down a size in pilot jet.
Now very slowly, open the fuel screw till the idle is smooth. Blip the throttle, let the bike return to an idle, wait say ten seconds. Confirm it is the same smooth idle.
If the screw has to be opened more than 3 turns to get a smooth idle, you need to go up a size in pilot jet.
If you find it does not stall with the larger jet but has to be open more than three turns with the smaller pilot jet, put the larger one in and set the fuel screw at 1/2 turn.
If the idle speed increased, adjust the idle speed knob to return the bike to a real slow idle speed. You must then re-visit the fuel screw. Keep doing this till the fuel screw is opened just enough to provide a nice steady idle at the lowest possible RPM. Once this is done, increase the idle speed to the normal one for your bike, typically about 1,800 rpm, but go by the spec in your manual.

Cold engine (not a cool day) you should need the choke. Hot engine, you may need the hot start.

Running the bike with a broken tranny is a time bomb. Bits of the broken parts could be migrating about, just waiting to jam the crank.....

  • RichFZR-WR

Posted August 02, 2010 - 01:52 PM

#3

Excellent as usual William1.
Welcome to the forum skin64. Act as a sponge and soak it all up.
When you get the 426 dailed in, they are great bikes.

  • mkporn

Posted August 02, 2010 - 03:14 PM

#4

2002 has Titanium valves.... Double check clearances.... I will put money on the center valve being tight....

Everything that William said above is great information but I would put money on a tight valve as everything you just explained points to it.

  • PirelliMan

Posted August 02, 2010 - 04:14 PM

#5

2002 has Titanium valves.... Double check clearances.... I will put money on the center valve being tight....

Everything that William said above is great information but I would put money on a tight valve as everything you just explained points to it.


I agree on checking the valves.

  • William1

Posted August 02, 2010 - 04:37 PM

#6

Tight valves makes cold starting a issue, not hot starting.

  • 4esh_numa

Posted August 03, 2010 - 04:22 AM

#7

Hello Skin, I have the same problem with my wr450f. i seem to have fixed the problem by just changing the fuel. it had only been sitting for 6 weeks. its amazing how fast fuel can go stale. Like william said check the fuel screw its highly possible it is that. please when you find out this problem let me know what it was. Cheers, James

  • mkporn

Posted August 04, 2010 - 06:00 AM

#8

Tight valves makes cold starting a issue, not hot starting.


Funny, seen this happen several times before...... But whatever, don't check the valves on a bike that you have no clue of the time on, has Ti valves and is known to have a starting issue.

So, quick question William, when a bike gets warm does the valve clearance shrink or grow?

  • William1

Posted August 04, 2010 - 08:34 AM

#9

As the bike heats up, the valve clearances increase. You have two componets, the valve stem and the head. Alluminum 'grows' more with heat than steel or Ti. So the head swelling increases the distance between the valve seat and the valve spring seat.

You are more or less right about engines of unknown condition. Guys try to jet away compression issues all the time. The moral is, if the bike is jetted right and one day, does not run right, it is not the jetting (unless the carb is dirty).

  • skin64

Posted August 05, 2010 - 12:24 AM

#10

Crikey, looks like I've opened a can of worms here! - Thanks for all of your replies, they've definately given me a few pointers.
With regard to valve clearances, I always thought that the clearance is reduced as the engine gets hotter due to expansion of the metals..??
Since my first post, I've had a closer look at the bike & the engine looks like it's been put together by Kermit the frog! - The carb' inlet rubber has been fitted incorrectly (the locating "slot" in the rubber doesn't locate with the carb'). Could this be an issue?
Anyway, I intend to strip the carb this weekend & give it the once over. I'm no expert, but I've borrowed a Haynes manual to check float heights etc. Keep the posts coming lads, they're all interesting & I'll keep you posted. - Skin.

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  • skin64

Posted August 22, 2010 - 01:48 PM

#11

Update... My mate came round the day before I was due to strip the WR. He has the same model & has owned it a few weeks longer than I've owned mine.
Anyway, as my right foot was still convalescing, he offered to start it (mine). 1... 2... Bang! The b@$#@rd started! - "How the f#$£"!%^&*()_+~?>< ing hell did you do that?", I eruditely enquired. "I always start mine with no choke", he said... "Just put the fuel tap on, no throttle, no choke & it'll start!"
I've since replaced the spark plug (purely for good measure) & have had no problems since!.. Happy days! - I've even been starting it up, wearing just flip-flops.. just to take the pi$$ out of it!

  • jonooffler

Posted August 23, 2010 - 12:05 AM

#12

Hi mate I saw this one on ebay, I will admit that the 5 gear bit and the fact the owner said it will run at 80 in 4th made me think a bit.
I got my 426 about two months ago I to start with I could not start it from cold one day I kicked it all day and still nothing .Then I changed the plug and found the right way to kick. Now she goes first time hot or cold.
Stick with this bike I have owned a XR250, DRz400 KDX220 and a Te610 this one is the best and I'm not going to let this one go.They are far better than the WR450 for Uk lanes.I would say that this bike has made me a much better rider.
Have a look at the hot start part of the carb it might just need a clean up.
All the best and fear not you have not bought a bad bike.
Jono

  • skin64

Posted August 24, 2010 - 08:44 AM

#13

Yes, I too saw that one on ebay, but I didn't buy that one. The one I bought wasn't advertised with a dodgy 5th gear (the b@$#@rd!). I only found out the following day when I took it for an MOT.
I rang the seller & ragged him a bit, but he wouldn't give me any money back. I had the last laugh though... I'd paid him a £200 deposit by paypal & he hadn't "claimed" it, so I cancelled it. tee hee.

  • jonooffler

Posted August 24, 2010 - 11:15 PM

#14

Hi mate glad to hear that you have sorted the starting issue with your bike, there is a nack to it .I looked at all the clips on youtube but none of them work like mine.
I always hate it when you get ripped off on ebay ,why do these jokers feel that they can get away with it .Mine was ready for an MOT or so the seller said the bike was great but it needed a lot of work before it was ready to get close to a MOT.
Drop me your adress and I can post you a cd of the work shop manual from Yamaha.
So far I have rebuilt the front forks on mine and rebuilt the rear end ,replaced the rear disk and pads .As I said I love this bike and I hope that you enjoy yours .
Jono

  • skin64

Posted August 26, 2010 - 03:49 AM

#15

Hi Jono & thanks for your kind offer. I've just bought a Yamaha service manual from ebay. Amazingly half the pages are missing & somebody's wiped their backside on it! (just joking!). - No, it's a good one really.
The fork seals have just gone on it now & I've got a pair of genuine seals to put in the forks. I've not read the manual yet but what should I expect? Any hurdles? - Cheers.

  • jonooffler

Posted August 27, 2010 - 08:54 AM

#16

Hi mate I'm lucky I have the paper one and a CD one both from Yamaha and they are pretty good .As for the forks I would say thay were the best ones I have ever done forks stripped down in about 10 mins and new seals went in no problems, you might need a seal driver look on ebay for WR seal driver there is a guy on there selling plastic ones for £2.99.
The only thing I might have got wrong was the oil level I added the amount they said but the level was at the high end , they do feel a bit hard.
I changes the bushes on mine but they didn't look to bad.
As I said if you need the CD just let me know.
Good luck on the change, by the way I used 5 wight oil on mine.
jono

  • dazzabb

Posted August 27, 2010 - 03:53 PM

#17

If you can't select 5th gear it's more than likely the selector fork that has been damaged.

Stripped my WR450 2 days ago, I had no 5th gear also.

Turned out to be a badly worn selector fork, the dogs on 5th gear and all the other gears were perfect which surprised me, I expected to find a crankcase full of metal pieces.

Hi all. I'm new to this forum & need your help if poss. Just bought a 2002 WR426 from ebay (I can hear the groans already!). Turns out that 5th gear is shagged & it seems to be a bas#@%d to start when "warm". I can live with the 4 gears for now. I'll strip it during the winter & put it right.
It's this starting problem that really gets my goat. My right foot has a massive bruise underneath from kicking the tw@ttin' thing! - When it's cold, it'll start first or second kick, but if you ride it a couple of miles & switch off, it'll start straight away, but if you leave it for 10 minutes or so, it takes about half an hour before it'll start again!
I know it has the cold & hot starting chokes & I'm wondering if I've not mastered them yet..? - I'd be really grateful for any advice as I've already knackered one right training shoe, one right boot, two pairs of socks & one right foot!!

Cheers, Skin.



  • dazzabb

Posted August 27, 2010 - 03:56 PM

#18

The fork seals are pretty simple.

You'll probably need a buzz gun to take out the bolt / damper at the bottom of the forks that holds the cartridge.

I used the old fork seals that I had just taken out as a driver, I cut them first to allow them to be twisted back onto the fork stanchion. Then just tapped them down gently on top of the new fork seal to locate them correctly.

  • jonooffler

Posted August 27, 2010 - 11:38 PM

#19

Nice tip on the fork seals.

  • skin64

Posted August 31, 2010 - 01:14 PM

#20

Cheers Dazza, great advice on the fork seals. With your input & a little help from the Yamaha manual, I've sorted em! - Using the old seal, cutting & twisting back on to the leg worked a treat.

Another thing, re: starting problem. I went out for a good ol' thrash down a few local green lanes with my mate (the flash bugger that got mine started) for a couple of hours last Sunday afternoon.

We upset a farmer, soaked a couple of women walking dogs & sent a horse & rider into a frenzy. It was great & a good time was had by most (but mainly us!).

Funny thing was, after a couple of hours hard riding & then returning home, the b@$#@rd wouldn't start again. My starting regime hadn't altered, so I thought, it must be down to the plug (that I'd previously replaced). I removed it & checked the gap.

It was approx' 5 thou' wider than when I set it...? - I've since renewed the plug again. This time with a CR8EIX iridium plug & hey presto, it's starting on request again.

It seems to be fouling plugs. I'm glad that I seem to've got to the root of the problem, but does anybody know why this is happening? -

Grateful for your input as usual. - Skin.




 
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