08 wr450, very hard to start in the AM


23 replies to this topic
  • Demo_Slug

Posted March 24, 2008 - 11:02 PM

#1

dam my bike was hard to start in the cold mornings this weekend. 2 days in a row I had to bump start it. (it bump starts easy) it has 600 miles on it and is bone stock except the throttle stop and grey wire and the GYTR baffle. the kicker is my 2 buds both have identical 08wr450s, they all have the same mods and mileage. their bikes fire right up :confused:


my starting technique is one throttle twist, pull out the enrichment then hit the estart a few times to prime it, then start kicking. this is the first time I've ever had a problem starting it.


I was going to toss in my JD kit in this week, but maybe I should fix my starting issue first. any insight would be appreciated.

maybe a new plug? check the valves? wave a rubber chicken at it?

  • JSanfilippo

Posted March 24, 2008 - 11:26 PM

#2

Try this

-Pull choke
-Two twists of the throttle
-Cycle the kickstart 3-4 times
-Find TDC
-Kick

My bike started sporadically. Some mornings one kick would get her lit and others it would take 3 or 4 kicks. Been doing that and it starts first kick every time.

How does it start hot?

Regardless, wouldn't be a bad time to pop the valve cover off and check your valve clearances.

  • Demo_Slug

Posted March 25, 2008 - 09:24 AM

#3

Try this

-Pull choke
-Two twists of the throttle
-Cycle the kickstart 3-4 times
-Find TDC
-Kick

My bike started sporadically. Some mornings one kick would get her lit and others it would take 3 or 4 kicks. Been doing that and it starts first kick every time.

How does it start hot?

Regardless, wouldn't be a bad time to pop the valve cover off and check your valve clearances.


It’ll start the rest of the day on the e start. It does have to crank a bit when its real Hot. I always seem to be the last guy to get his bike to fire. It ‘ll kick start first or second try when its hot.

I did have fresh oil that morning and I had used 20w50 yamalube. Which is what they sold me with the bike. I got a gallon of the stuff. It was freezing cold that morning… so per the owners manual I should have been using 10W40. maybe the oil is just to thick.

I’m 240 pounds and I couldn’t make the kick start move on the compresion stroke.

  • CheYuen

Posted March 25, 2008 - 09:53 AM

#4

I'm not sure about the resistance that you're experiencing from the kick start at TDC, but everything that I have read here is that you should kick before using the e-start. I would say that jetting may very well be your problem. :confused: Instead of "trying to fix the starting issue first", just re-jet. It made a big difference with my bike.

  • Demo_Slug

Posted March 25, 2008 - 11:25 AM

#5

I'm not sure about the resistance that you're experiencing from the kick start at TDC, but everything that I have read here is that you should kick before using the e-start. I would say that jetting may very well be your problem. :confused: Instead of "trying to fix the starting issue first", just re-jet. It made a big difference with my bike.


kinda hard to blame jetting when you have three identical bikes and only one of them won't start. :excuseme: I could just chalk it up to veriance in the manufacturing. maybe my bike was built on friday :excuseme:

  • dirtysouth

Posted March 25, 2008 - 11:52 AM

#6

Man, once you get the jetting dialed in (and that might take some reading here to understand) you should be able to kick it or push the button and fire it right off anytime. Once I figured mine out it fires no problem. I have had tough starting times in cold weather but subsequently rejetted and the issues diminish. Read as much as you can in the jetting threads and use your judgement since anyone can post here. I learned what little I know from reading here. Do a search for starter jets and read how they work with different set ups. Search fuel screw too. Read the sticky about jetting database to get a good starting point. Good Luck

  • William1

Posted March 25, 2008 - 12:31 PM

#7

Hard cold starting can be tight valves, but not in your case as I assume you have low hours. It can also be a bad plug or one that has too large a gap. Easy enough to check. I found my 08 WR had a gap nearly double the book setting. Once gapped properly, it fires up cold without too much trouble. I also put in a larger stater jet, went from the stock 68 to a 72. I still have to twist the throttle a couple of times before pushing the button, but then it fires up immediately. Choke can come off in 10 to 15 seconds.

  • xBRIANx

Posted March 25, 2008 - 12:48 PM

#8

hmm
i usually throttle it like 3-4 times, choke out, kick it maybe 2-4 times, and it starts right up. not rejetted either, Grey Wire, baffle, umm, and throttle screw. maybe a couple more turns of the throttle is what u need?

  • Demo_Slug

Posted March 25, 2008 - 12:50 PM

#9

Man, once you get the jetting dialed in (and that might take some reading here to understand) you should be able to kick it or push the button and fire it right off anytime. Once I figured mine out it fires no problem. I have had tough starting times in cold weather but subsequently rejetted and the issues diminish. Read as much as you can in the jetting threads and use your judgement since anyone can post here. I learned what little I know from reading here. Do a search for starter jets and read how they work with different set ups. Search fuel screw too. Read the sticky about jetting database to get a good starting point. Good Luck


OK, soooooo in regards to jetting. Would I need to go richer or leaner?? Was I not getting enough gas or had I flooded it?

Also I saw a few hints about leaning the bike over to get it to start? Is that to get more gas in the float bowl?

  • JSanfilippo

Posted March 25, 2008 - 12:53 PM

#10

OK, soooooo in regards to jetting. Would I need to go richer or leaner?? Was I not getting enough gas or had I flooded it?

Also I saw a few hints about leaning the bike over to get it to start? Is that to get more gas in the float bowl?


What is the elevation you ride at?
Temps?
What jetting did yamaha put in these things for '08

Generally, you go richer because they come so lean from the factory. People at really high altitudes (Like 9000+ft) might not have to rejet.

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  • Demo_Slug

Posted March 25, 2008 - 01:35 PM

#11

What is the elevation you ride at?
Temps?
What jetting did yamaha put in these things for '08

Generally, you go richer because they come so lean from the factory. People at really high altitudes (Like 9000+ft) might not have to rejet.


Sorry I didn’t word that question very well. I meant to say “jetting in regards to cold starting.” Given that the topic of this post is my cold starting and I keep hearing “rejet”. But in my simple mind, rejet = use my JD kit. And I’m kinda stumped on how changing my needle and Main jet will help it start, given that I don’t crack the throttle while its starting. The Oring might pump more gas in, if I was not giving the AP circuit enough time to spew all its fuel. but besides that I don’t see it.

Adding a fuel screw and tweaking it might work. Or changing that starter jet thingy.

In this case the cold start was at 2300feet and it was about 35 degrees. Being that it was 8:00 AM.

And I may be overly worried about flooding it. given that other people seem to squirt three twists into it before they try and start it. and I only did one. but after 60-80kicks by three people and a near dead battery, I kind loose count of how many times the throttle has been turned. but it started easy on a bump.

  • anathema

Posted March 25, 2008 - 03:20 PM

#12

As said before, if you know your jetting is dialed, a progressive hard start is most likely valves or maybe a failing stator. I'd check your valves asap.

Otherwise I'd say you have a jetting problem.

  • kevinwr450f

Posted March 25, 2008 - 06:12 PM

#13

My '07 fires right up when cold by just choking it and hitting the magic button. I've only had to kick my bike once in 14 months, that was because my petcock was not turned all the way to reserve and the bike quit on me. I killed the battery that day......

  • sausage boy

Posted March 25, 2008 - 06:52 PM

#14

on my 05 WR450 i pull the choke out and press the e-start, it starts right away first prod, i didn't know about needing to kick it over 1st.
i had a friend who always kicked his 04 WR450 then one day he pressed the e-start at the same time at kicking it over, it shot the kickstart shaft out the side of the casing, made a real mess...

  • sausage boy

Posted March 25, 2008 - 07:00 PM

#15

Hard cold starting can be tight valves, but not in your case as I assume you have low hours. It can also be a bad plug or one that has too large a gap. Easy enough to check. I found my 08 WR had a gap nearly double the book setting. Once gapped properly, it fires up cold without too much trouble. I also put in a larger stater jet, went from the stock 68 to a 72. I still have to twist the throttle a couple of times before pushing the button, but then it fires up immediately. Choke can come off in 10 to 15 seconds.


it could be your valves it says in the book check after the 1st 500 miles, when i had a problem with my valves it was stalling though not starting, i'd agree with will and check the pulg gap, or even replace it and gap a new one. i'd also check that the right plug was put in at the factory. either way ou need to look at that plug to see whats happening with your jetting. :prof:

  • Demo_Slug

Posted March 25, 2008 - 08:07 PM

#16

it could be your valves it says in the book check after the 1st 500 miles, when i had a problem with my valves it was stalling though not starting, i'd agree with will and check the pulg gap, or even replace it and gap a new one. i'd also check that the right plug was put in at the factory. either way ou need to look at that plug to see whats happening with your jetting. :prof:


my yamaha manual says 600miles.

http://www.yamaha-mo...8WR450F_643.pdf

  • William1

Posted March 26, 2008 - 02:48 AM

#17

If you bike runs well once heated up, your jetting is fine (or nearly fine). The only thing left jetting wise is the starter jet.

  • Demo_Slug

Posted March 26, 2008 - 10:19 AM

#18

If you bike runs well once heated up, your jetting is fine (or nearly fine). The only thing left jetting wise is the starter jet.


Thanks Will….

Seems like a larger starter jet is common. I'll look into that if my valves and ignition are OK.

I got my fingers crossed that it’s a plug or dirt in the carb. I’d be very disappointed if my WR zeroed its valves in less then 40 hours.

  • Demo_Slug

Posted March 27, 2008 - 09:47 PM

#19

I got to my valves and they are out of spec. but they are not zeroed :prof:


from left to right. they are all tight on the chain side.
intake: 0.08mm, 0.1mm and 0.13mm
exhaust: 0.15 and 0.2mm

I guess thats the price for rolling deep.

but seems doubtfull that this is the source of my starting issue???? I guess I'm kinda surprised that they are out so early.

  • Alternative

Posted March 29, 2008 - 04:34 AM

#20

Initially, new titanium valves can stretch quite a bit, but after a few adjustments they will settle down and not need adjusting for a while.




 
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