Quick question... yz450f - bear to start - not valves - starts right up when warm.


37 replies to this topic
  • Jaycycle

Posted August 27, 2006 - 10:12 AM

#1

Sorry for another one of the ridiculous "wont start" questions but here it is. I just check my valves 10 minutes ago. Everything is was good except the right intake was a LITTLE tight... but still in spec. Then once the tank was on I tried to start it and just like ever time I start the engine cold it takes way to many kicks to get her started. But once shes up and running she is a breeze to start, first kick guaranteed even after it is dumped (most likely). It just sucks cuz its for sale and I don't wont someone to come look at the bike and watch me kicking it a million times. And I know being a thumper your not suppose to but usually giving it some gas helps getting it started.

Help! :thumbsup:

I just had a thought that maybe the plunger is stuck open a little bit.. I'm going to go check that really quick and grease it good.
Nope that wasn't it.

  • SureBlue

Posted August 27, 2006 - 11:04 AM

#2

Raise the idle and give it 3 blips, it's not getting enough gas and wont start if the idle is set too low.

  • CROGGR

Posted August 27, 2006 - 11:07 AM

#3

The pilot jet is way too lean on the 06. Go to a 48 pilot. And yes, you may have to blip the throttle once or twice when cold.

  • Jaycycle

Posted August 27, 2006 - 11:10 AM

#4

The pilot jet is way too lean on the 06. Go to a 48 pilot. And yes, you may have to blip the throttle once or twice when cold.

Its on my 03... But I still think I may have to go up one on my pilot jet? (from what I have read anyways) The thing is I have never screwed around with the carb.

  • Jaycycle

Posted August 27, 2006 - 11:30 AM

#5

Raise the idle and give it 3 blips, it's not getting enough gas and wont start if the idle is set too low.

I have messed around with the Idle so much. I just cant figure it out, nothing is really working to help it start easier. :thumbsup:

  • barch88

Posted August 27, 2006 - 11:41 AM

#6

Change the plug.

  • Jaycycle

Posted August 27, 2006 - 11:46 AM

#7

Change the plug.

I pulled the plug when I did the valves and cleaned it. It had a good spark so I threw it back in.

  • barch88

Posted August 27, 2006 - 11:48 AM

#8

Clean air-filter? I'm just going off the basics right now...

  • Jaycycle

Posted August 27, 2006 - 11:58 AM

#9

Yes of course... I'm a very meticulous when it comes to my bikes. :thumbsup:

but keep the ideas rollin.

  • barch88

Posted August 27, 2006 - 12:02 PM

#10

Yes of course... I'm a very meticulous when it comes to my bikes. :thumbsup:

but keep the ideas rollin.

Yeah, figured you were, so am I. Hmm...well I'm out man, good luck.

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

Posted August 27, 2006 - 12:04 PM

#11

I pulled the plug when I did the valves and cleaned it. It had a good spark so I threw it back in.

Change it anyway.

  • CRF250dude26

Posted August 27, 2006 - 01:53 PM

#12

Adjust the fuel screw :thumbsup:

  • bg10459

Posted August 27, 2006 - 02:07 PM

#13

For cold starts with the choke, try a #70 starter jet. :thumbsup:

  • Jaycycle

Posted August 27, 2006 - 03:05 PM

#14

Adjust the fuel screw :thumbsup:

Ahh okay, I give up... I can't find the darn screw. Cant find it on the carb or in the manual. I need help on this one :ride:

  • Satch0922

Posted August 27, 2006 - 03:59 PM

#15

it is on the bottom of the carb ( imagine the carb off the bike and your looking straight up at it from the bottm). It is the small screw at the front center of the float bowl.

See the "home made" on the fly fuel screw that Motoman 393 made.....that is where the fuel screw is.

Posted Image

  • grayracer513

Posted August 27, 2006 - 04:06 PM

#16

If it starts good hot, leave the pilot alone, unless there is some other reason to mess with it.

My '03 has never followed the text book form for cold starts, but I get it going in one or two most every time.

Gas on, choke on, 3-4 twists on the throttle to prime it. Push it through once from where ever it is to the next compression stroke with the throttle closed. Crack the throttle just off idle, like an eighth or less and hold it there. Give it a full kick through, and it should light right up.

Try it.

  • Jaycycle

Posted August 27, 2006 - 04:15 PM

#17

If it starts good hot, leave the pilot alone, unless there is some other reason to mess with it.

My '03 has never followed the text book form for cold starts, but I get it going in one or two most every time.

Gas on, choke on, 3-4 twists on the throttle to prime it. Push it through once from where ever it is to the next compression stroke with the throttle closed. Crack the throttle just off idle, like an eighth or less and hold it there. Give it a full kick through, and it should light right up.

Try it.

Gray I think you may have the ticket their.... But how exactly do you find the compression stoke well kicking it over :ride:.

Ding ding ding I think we have a winner :applause:. I'm going to try it again tomorrow when I know the engine is cold and my foot heals. Then again grays the man :thumbsup:

  • 03yz450f-43

Posted August 28, 2006 - 04:12 AM

#18

If it starts good hot, leave the pilot alone, unless there is some other reason to mess with it.

My '03 has never followed the text book form for cold starts, but I get it going in one or two most every time.

Gas on, choke on, 3-4 twists on the throttle to prime it. Push it through once from where ever it is to the next compression stroke with the throttle closed. Crack the throttle just off idle, like an eighth or less and hold it there. Give it a full kick through, and it should light right up.

Try it.


Once again Gray is the man. I have an 03 and this is exactly how I start it. First or second kick everytime.

:thumbsup: :ride: :applause:

  • Ga426owner

Posted August 28, 2006 - 05:01 AM

#19

Ahh okay, I give up... I can't find the darn screw. Cant find it on the carb or in the manual. I need help on this one :thumbsup:


This is not meant to be a slam......please tell me you are not serious? You can check valves but you can not check the air/fuel adjuster? The fuel screw and adjustments for temp and humidity changes are a manditory integral part of owning any Yami........so I assume it has never been adjusted? Here is part 1 of your problem.

The 03 starting technigue is different for almost every 03 - In your case I assume everything is totally stock jetting - Greys techique will work for you.

Carb probably needs to be cleaned

  • Jaycycle

Posted August 28, 2006 - 08:29 AM

#20

This is not meant to be a slam

Thats okay, I was ready for it.

......please tell me you are not serious?

Im not going to lie...
(I Just could never find the damn thing so I didn't bother.)

You can check valves but you can not check the air/fuel adjuster?

Its the simple things in life. :thumbsup:

The fuel screw and adjustments for temp and humidity changes are a manditory integral part of owning any Yami

IK :ride:

........so I assume it has never been adjusted? In your case I assume everything is totally stock jetting

I'm not the first owner so it probably has.

:applause:





Related Content

Forums
Photo

Is it worth it? (Cam and High compression piston) by macgi77


Dirt Bike   Make / Model Specific   Honda   CRF 150/230 F/L
  • Hot  36 replies
Reviews

Yamaha YZ450F 2017 by Chris.GVS


Yamaha YZ450F 2017
  • - - - - -
  • 0 reviews
Forums
Photo

Megabomb Fitment by 288yz450


Dirt Bike   Make / Model Specific   Yamaha   YZ 400/426/450
  • 1 reply
Forums
Photo

James Stewart back on a YZ450F by YamaLink


Dirt Bike   Special Interest Forums   Pro Racing
  • Hot  47 replies
Forums
Photo

2016 YZ450 by CaptainKnobby


Dirt Bike   Dirt Bike Technical Forums   Suspension
  • Hot  59 replies
 
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.