Why is my bike so hard to start??????


13 replies to this topic
  • S1rst

Posted January 31, 2009 - 03:28 PM

#1

As above, why is my bike so hard to start from cold???? It seems to be getting worse lately! It took me a good 5 minutes to get the bike going this morning, it was a nightmare! Once it starts it will fire up first time all day long, no problem at all. When i first got it, all it needed from stone cold was a couple of twists of the throttle, choke on, and it fired up straight away.

The bikes an 08 WR450f done around a 1000 miles now, all standard, but has exhaust restrictors removed and shorter throttle stop, other than that, totally standard mechanically.

Anyone have any suggestions for me or are they all like this when trying to start from stone cold????

Cheers. :)

  • WRtaz

Posted January 31, 2009 - 04:38 PM

#2

This is what works for me normally in the cold or if it's been sitting for a while, turn fuel on, choke on, full throttle twice, hit the starter. 9 out of 10 times it starts by the second try. If not I crack the throttle one more time and it'll fire. It seems if you giving it throttle while hitting the starter, it'll just make things worse.

Fyi, I have a 07 wr450 uncorcked and re-jetted.

  • HusQyGuy

Posted January 31, 2009 - 04:42 PM

#3

what i've heard is jetting is the key, or crank the fuel into your carb a little more.

  • brad the best

Posted January 31, 2009 - 05:00 PM

#4

if mine doesnt want to start for some weird reason , i give ti to twists , hit the e-start for 10 seconds then kick it for a bit then e-start it usually starts then . or just keep alternating till it goes .

for some reason mine starts on the starter in the winter and kicker in the summer .

  • Krannie McKranface

Posted January 31, 2009 - 07:07 PM

#5

It could be one or more of several things:

- adjust fuel screw
- dirty pilot jet
- dirty/clogged aircleaner
- bad plug
- old gas
- air leak (loose boots, header)

Jetting to match your modifications is not really an option. Any change to the trio of air in, exhaust out, fuel mixture, with affect everything. Try reading the stickies at the top of the forum, and pick a tuning you thing would work best for your bike, and give it a try. At the very least you should try a Jetting Kit like JD.

  • chris_TTR250

Posted January 31, 2009 - 07:51 PM

#6

My 450 bike always starts from cold better with the kick starter seems like the starter motor doesn't turn it over as fast. I go, choke on and usually the 1st or second kick is all it needs.

It may be worth checking you valve clearances, I know yamaha has an awesome reputation but on the hondas they know there out when they become difficult to start.

  • S1rst

Posted February 01, 2009 - 06:04 AM

#7

Thanks for all the suggestions. Plenty for me to check and look into there. :)

After spending all day on it yesterday, ive gone out to it this morning, done the usual 2 twists, choke on and it fired up instantly. It seems to be hard to start when its left for like a week or so.

Will me leaving the fuel on all the time cause this to happen, like its flooding it as fuel continues to fill the carb gradually maybe?

Visit the ThumperTalk Store for the lowest prices on motorcycle / ATV parts and accessories - Guaranteed
  • Krannie McKranface

Posted February 01, 2009 - 06:57 AM

#8

Thanks for all the suggestions. Plenty for me to check and look into there. :)

After spending all day on it yesterday, ive gone out to it this morning, done the usual 2 twists, choke on and it fired up instantly. It seems to be hard to start when its left for like a week or so.

Will me leaving the fuel on all the time cause this to happen, like its flooding it as fuel continues to fill the carb gradually maybe?


You might want to check your float needle and seat, as if you do leave the fuel on all the time, the float needle and seat can leak, overfilling your float bowl.
Also, you might try kicking the bike a few times with the ignition off with no throttle, if the bike has been sitting, to clear the cylinder.

  • Bamster

Posted February 01, 2009 - 07:02 AM

#9

Check your valve clearances. When the valves get tight the wr gets harder to start.

  • CanadianWR450

Posted February 01, 2009 - 07:04 AM

#10

I'm not a expert, but since I'm getting ready to tear mine down and do some work to get ready for spring, I have been digging around on here a LOT.

I know I saw somewhere that a bike that suddenly starts getting hard to start, and you did nothing to change anything, is a sign that the valves may need to be adjusted....

I would say valve adjustment needs to be down at LEAST once a year (if you can't/don't ride all year round...)

Just something to consider. A lot of ppl on here should have more info on this then I do....lol

EDIT - Bamster beat me to it while i was typing!
haha!

  • oldmanx

Posted February 01, 2009 - 07:06 AM

#11

With both my 04 WR450 and my buddy's 02 YZ426, if the bikes don't start on the first cold attempt what seems to work is to lay the bike over until fuel flows out the overflow. The a twist or 2 of the throttle and they fire right up.
If this is a cold start only issue, I'd think that its more of a fuel and not valve clearance issue...but then what do I know...

  • flynz

Posted February 07, 2009 - 10:13 PM

#12

When very cold outside mine starts better with kick starter for the first start the starter doesn't have enough umph to fire the engine but always starts with one or two kicks

  • S1rst

Posted February 08, 2009 - 02:54 AM

#13

Hi, thanks for all the replies. I tried to a few different things as mentioned in this thread, and it seems that it was just my technique that wasnt so good. I always thought the starter is fine and as good as the kick start, but obviously thats not the case.

I turned the fuel off before putting it away last time (as i usually leave it on all the time), and after getting it out the garage last night, and in -3 temperatures, i kicked it a couple of times with ignition off, then choke on, ignition on, and after 2 kicks it fired up straight away! So ill be using this method from now on! Cheers all. :lol: :)

  • Wes Woodin

Posted February 08, 2009 - 06:15 AM

#14

You might want to check your float needle and seat, as if you do leave the fuel on all the time, the float needle and seat can leak, overfilling your float bowl.
Also, you might try kicking the bike a few times with the ignition off with no throttle, if the bike has been sitting, to clear the cylinder.

This is where I was gonna go. Sometimes the float will stick and simply won't let the gas into the bowl. Change the bowl and seat. Its cheap. I would drop the bowl and check for debris also. Most usually it's the jetting. I have a 2008 and was running VP u4. I had left it in for only a couple of days. What had happened was the AP accelerator pump diaphram got a tear in it. It was impossible to start, so I replaced it. It fixed the problem. I also usually crack the throttle 5-8 times prior to starting to prime the cylinder. Cranks the first or second time. My jetting is spot on though. I ride at 850 elevation and run 100 octane with powerbowl with a 52 pilot, 3 screws out on leakjet, 170 main. Good luck!:)




 
x

Join Our Community!

Even if you don't want to post, registered members get access to tools that make finding & following the good stuff easier.

If you enjoyed reading about "" here in the ThumperTalk archive, you'll LOVE our community. Come join ThumperTalk today!

The views and opinions expressed on this page are strictly those of the author, and have not been reviewed or approved by ThumperTalk.