Cold Starting

[sdguy]

Even as I dig out from the winter blast I know that this is RC and the Black Hills and there will be a number of days to ride throughout the winter.  I have a 2008 that I bought in July and always needs to be choked to get it started in the morning.  The problem I am noticing is the starting when it is cold out.  The first time it happened was on a fall camping trip in the Black Hills and the temp dropped into the 30s and had to work at it for almost 5 minutes to get it started.  Is there anyone that  might have a suggestion on what the problem maybe and how to fix it?  I am pretty mechanical inclined but new to motorcycles so really a rookie at this type of work.  So if it not something simple who is a respectable mechanic if it can't be fixed under warrenty.  Thanks for the help.

Garry

[The Yeti]

Hank will be here shortly with an answer, I'm sure! Sorry, I'm pretty mechanically inept...

When we gonna get together for a ride (I'm in RC also)? I'll screw in some studs and we can go out tomorrow!! 

[LittleJacket]

My 03 klr has always been a cold starter as well and I've heard most klr's are.  I always use full choke-even in the summer when starting and the bike is fine.  When I bought the bike, I was told to let the bike run on full choke until you can see oil drip through the spyglass to ensure that oil gets to the top part of the motor, as low rpm's have a tougher time pumping the oil all the way to the top. Not sure if there's any truth to that, but the bike has never given me any problems.  The choke on the klr doesn't seem to respond like a choke on a lawnmower or snowblower.  It seems to hold the engine at higher rpm's but doesn't cause the bike to quit if left on.  Maybe it's different?

[Hank]

I think the carb shimming mod (.22 cent mod as its known elsewhere) should help with cold starting as it richens things up abit , but I can't say for sure.  Ryan or Dustin, have you tried starting your KLR in cold weather since you did it to yours?   

My '00 KLR was terribly cold blooded.  It was hard to start at anything less than 40 degrees.  I had planned to do the mod but sold it to my bro-in-law before it got done.

[fringefan]

You can turn the mixture screw about a half turn and it should help with the cold starting. I have the adjutable needle on mine and it starts way better than it ever did before to the point I do not always have to use the choke in the summer and when I do it is for a short time. I will probably do the .22 cent mod this winter.

[Dustin]

It was 23 degrees in my garage this morning and my KLR fired up with no hesitaion. I did the .22 cent mod along with adjusting the pilot screw out. I originally had a very hard starting bike, but it had pretty good MPG. Now with the mod and pilot adjustment I get a little lower MPG, usually aroung 38mpg.

Oh yea.... I also drilled out the slide orifice.

[fringefan]

Seems some guys still get around 46 and you and Ryan get less than 40. Wonder what the makes the difference? I put the tractor muffler on and it flows a little better than stock and is causing mine to run a little warm so I am going to try the .22 to attempt to rectify the issues.

[sdguy]

Hi, thanks for the replies.  I will have to look into the .22 mod.  I am beginning to think mine my be set real lean as I consistantly get 50+ mpg in town, and with some hills cruising have been in the high 50s for mpg.

[loingrader]

one thing.  when it is cold out, put the choke on full but don't touch the throttle.  if you give it throttle when the choke is on it will suck air instead of fuel and will start much harder. 

i haven't touched the carb on my 92 and it fires up at 10 below zero, no problem.  you said you were new to motorcycles, just wanted to make sure you knew to not touch the throttle when starting with the choke on.

[fringefan]

I have heard the 08's getting better mpg with some getting over 60.

[Jared]

I only get 41 or 42 or so.  I haven't done the pilot screw thing or the .22 deal yet.  I have added the PCV valve and removed the rubber snorkel FWIW.

[hayduke.klr07]

anybody scared of using starter fluid?

[OOFDA]

I am. Only because it dries out the cylinder walls and causes scoring. It also can coat the electrode on the spark plug causing it not to fire. I saw a guy using gobs of it on a old worn out Chevy truck engine. When it finally did fire it blew the oil pan off the block. No problem finding the pan bolts, they were still in the block. Other than this I have no problem with ether. It works great for seating beads on rims, if done by someone else.
OOFDA

[The Yeti]

2010 WR250R
MSRP*   $6,390 (Team Yamaha Blue/White) Available from September 2009

Engine
Type   250cc liquid-cooled DOHC 4-stroke; 4 valves
Bore x Stroke   77.0 x 53.6mm
Compression Ratio   11.8:1
Fuel Delivery   Fuel injection  <----   


Just started my WRR for the first time in 5 months. Started right up, just like she'd been running 5 mins before!  I love FI!   

[Number Two]

If you are having to use some choke while it's warm, and it starts harder the colder you get, it's probably just lean down there.  Air fuel ratios while running hot should be around the stochiometric 14.7:1.  Fuel has a difficult time breaking into small droplets the colder it gets.  During the power stroke of your engine, only the outside layer of these unusually large droplets burns.  You are only extracting useful energy from a fraction of the fuel you would normally be burning.  So carb designers decided the solution would be to simply throw more fuel at it.  This works.  Cold start fuel ratios can creep below 8:1, which would be enough to stall an engine after it had reached normal operating temperature.  Your best option would be to modify the choke circuit to deliver more fuel, so you don't lose your nice fuel efficient settings on the primary circuits.  As an alternative, you could adjust the air screw or pilot jet to make more fuel at idle. 

Loingrader's comment about not touching the throttle is true.  Most modern carbs have an enrichener circuit, not a choke.  That means venturi vacuum draws additional fuel through the enrichener circuit.  The signal to the enrichener is inversely proportional to throttle position.  When you open the throttle, the air in the venturi slows down and creates less vacuum, confounding the cold start problem.  If you have an acclerator pump however, you can give it a few squirts before you crank it over.

I think the most KLR-esque solution would be to add the primer bulb from a chainsaw on the handlebars.  I can see KLR farkle envy brewing...