Bike will not start...weather??? HELP



11 replies to this topic
  • ThomasYZ426F

Posted December 26, 2001 - 03:40 AM

#1

Hello Everyone,
I just completed the BK Mod (it rocks). I rode the bike a one time after I did the Mod (for about 15 minutes) and it ran great.

A couple of days later, I tried to start the bike and it would not even try to start.

The weather went from mid to high 50's to low 30's for a high.

Could the weather be the cause of the bike not starting or could it be a bad plug?

As always, thats for the help.

  • sirthumpalot

Posted December 26, 2001 - 04:41 AM

#2

I've learned with these bikes that if it doesn't start in about 10 kicks then don't waste your time and just swap the plug. If it starts then you know the plug was bad and you can look for the reason why.

  • Tom_in_KS

Posted December 26, 2001 - 04:48 AM

#3

It's cold in my area now and I have found over the past two years of owning my bike that it does not like to start in the cold.

If I have not ran it for over a week, I have to kick mine over 10 to 15 time or more to get it to fire. I even have to blip the gas once or twice.

It only seems to be a problem when it's cold but that does not mean the cold is the ony problem I have with the bike. I am not brave enough to work on the carb my self and I admitedly think it needs some tunning but again it starts fine on the first or second kick when the temp outside is warm.

  • ThomasYZ426F

Posted December 26, 2001 - 04:59 AM

#4

I'm the same way Tom.

I don't really know that much about the ike yet to break into the carb.

I had a guy help me do the BK Mod (all I really did is watch).

I'm using that same plug that can with the bike, si I'll change it and see what happens.

  • Jason_in_KC

Posted December 26, 2001 - 07:00 AM

#5

This cold really bites eh Tom..Kansas City is getting the same as you.
These bikes can be tough in the cold...I noticed while just experimenting that my bike likes the float bowl to be filled w/fresh fuel from the tank after sitting more than a day. When I bring it home from riding..I just drain the float bowl back into my gas can. It seems to start more consistently w/new fuel from the tank..also..if you have done the BK mod..give the throttle two full twists before kicking..mine will fire within three kicks. Give it a try and good luck...with the temps dropping richen the fuel screw and even try going up to a 45 pilot. Changing the pilot is very simple and quick.

  • Guest_Guest_*

Posted December 26, 2001 - 07:04 AM

#6

When it is cold your bike will run lean. Cold bikes want a rich mixture which is what the choke does. However your choke can't give enough richness to start the bike if the pilot jet is too lean for the temperature.

On my stock 2001 426 with a #42 pilot jet, I do two things to start the bike in colder weather (normal is 70-90 degress, cold is 40-50 degrees):

(1) Check to see how many turns out your fuel screw is. If it is less than 2.75 turns turn it out at least a half-turn more (but not more than 2.75. I have had to turn mine out a full turn when the temperature dropped from 80s to 40s.

(2) Give a "blip" of the throttle before kicking.

My bike will still run lean when it is cold though (slight popping on decel and hanging idle).

I am going to change to a 45 pilot until it get's warmer. This is really a simple task, just rotate the carb (do a search for the instructions), take off the float bowl, take out the old pilot, put the new one in...

Hope this helps!


Steve T

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

Posted December 26, 2001 - 07:09 AM

#7

BTW - once you figure out that the choke richens the mixture and the hot start leans the mixture, your bike will be easier to start in all situations. You will know what to do to get the right "starting" mixture - cold bikes want rich, hot bikes want lean.

For example, if it is cold weather and you are running a little lean (hanging idle or popping on decel) it is really not required to use the hot start button after a break (at least on my bike). The bike might be lean enough as it is. It's also why a "blip" of the throttle when cold is good but when hot is BAD!


Also, bikes can foul a plug and make it smell like gas even when too lean. Don't get fooled into thinking the bike was/is rich.

Regards,

Steve T

  • Jason_in_KC

Posted December 26, 2001 - 08:22 AM

#8

FYI...anyone that is taking off the float bowl to change the main/pilot is making life rough on themselves! If you rotate the carb, there is a 17mm bolt on the bottom of the float bowl. If you take this out you can access the main and pilot for quick and easy changes...2-3minutes tops..don't forget to drain the bowl first though! :)

  • Guest_Guest_*

Posted December 26, 2001 - 09:05 AM

#9

Oops sorry about that. You are absolutely right - the pilot is easy to get to through the bolt hole on the bottom of the float bowl...

My bad!

Steve T

  • Tom_in_KS

Posted December 26, 2001 - 09:51 AM

#10

Hey Jason in KC, you are right the cold sucks...

Hey since you are in the KC area, are there any cool places to ride between Wichita and KC?

I have heard of some places around Tuttle Creek/Manhatan and some around Lawrence but I don't know the names or how to get to them.

Riding areas and tracks in and around Wichita are pretty SAD! I am looking for a good place to hit it for a road trip.

Later

  • Jason_in_KC

Posted December 27, 2001 - 04:10 AM

#11

Tom in KS...I just sent you a private message...go to the top of the page and click "my profile"..in case you haven't used it yet. Jason

  • Boit

Posted December 27, 2001 - 09:09 PM

#12

You don't even need to rotate the carb to change either jets. Just drain the bowl and remove the plug with a 17mm wrench, then, using one of those mechanic's mirrors, take a look up inside the carb to get a visual location of the jets and you can change them easily. The main jet can be changed in less than 5 minutes. The pilot is little more difficult to get at since you need a small flat blade screwdriver and a delicate touch.





Related Content

Forums
Photo

First Hare scramble tips by dhend8


Dirt Bike   General Dirt Bike Forums   General Dirt Bike Discussion
  • Hot  33 replies
Forums
Photo

Megabomb Fitment by 288yz450


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

Michigan Motocross Tires by 288yz450


Dirt Bike   Dirt Bike Regional Discussion   North
  • 1 reply
Reviews

Yamaha YZ450F 2017 by Chris.GVS


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

yz250x vs 450 4t comparisons (preferably desert riding) needed by JakeNorthrupYZ450F


Dirt Bike   Make / Model Specific   Yamaha   Yamaha 2-Stroke
  • 9 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.