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04 WR450 COLD STARTING


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Just wondering if all Wr's are as hard to start as mine when they're cold? This bike is brand new yet when I start it cold in the garage (40-50 degrees F.) I have to crank it about 10 seconds straight and do this 4 or 5 times before it'll hit. It will pop (like it's lean) a few times before it starts. Gas on , choke on should be enough but I've even tried twistin' the throttle a few times before starting (accelerator pump) but this makes no differance. This is my first 4 stroke and I'm still learning. But it sure sounds lean to me. Damn this things cold blooded!

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well hoss you have gotten into one of your bikes "things i need to learn about my new bike" subjects. if you do a search your going to find a lot on this. we've all been through it. first off, change to a bigger starter jet. a lot of us have gone to a 72 for the winter. that may be a bit much when it gets to 70F but will work well when still in the 40's. yamaha's number is 3TJ-1494F-16. don't be afraid to twist the throttle four or five times before starting. one bit of warning, don't touch the throttle when your pushing the start button! the bike has a throttle position sensor. it'll try to adjust the spark advance and can make starting even harder.

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The manual doesn't recommend cranking over 4 seconds, if I remember correctly. Try this - it's a good way to get some oil circulating before starting, too - Don't touch the throttle, crank 3 times for 4 seconds with the choke closed, then open the choke, crank in 3-4 second bursts until it fires. I like to keep my hand on the choke to give it minimum RPM while it is cold, so I play with the choke to keep it running, not revving. While it is not as cold here, I often start it when it's 48-55 and this works well. Yes, mine needs this amount to fire also.

Liking the bike so far?

Jim

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Hoss, I had the same problem with my bike and it seems like the quick answer that everyone gives is "Get a new starter jet". I agree that it will obviously help things but in my opinion that's not what you need to fix your problem.

Pretty much the first 15-20 miles the bike was a pain to start. I am assuming it has more to do with the engine being new and not broken in. I went out this weekend and was a bit worried about stauling on the trails and the bike starting with the 'magic button'. To my suprise and happiness I did not have a single problem this weekend. I even let a fellow 2 stroker hop on it and he gave it a couple throttle twists(bad) and the bike still started easily after a couple turns.

Kind of long winded but if I were you I would;

1. Make sure you use the choke when cold starting and give

it a few squirts previous.

2. After it's started and is 'warm' don't use the choke(I

hosed myself on this one)

3. Just let the bike break-in and see if things improve.

?

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After many flat batterys and cursing i finally read a post about the 72 starter jet.I couldn't get into my dealer fast enough.In australia the biggest starter jet is 70.I got this and now it starts as easy as a drz.Try one first , there cheap and easy to fit and you will make a better bike out of it.

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Twisting the throttle when it is off causes the accelerator pump to squirt raw gas inwards each time, washing all oil off the cylinder wall and contributing to increased cylinder, piston and ring wear. It will also contaminate your oil more quickly. What's wrong with a little extra cranking when it's cold?

Jim

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Twisting the throttle when it is off causes the accelerator pump to squirt raw gas inwards each time, washing all oil off the cylinder wall and contributing to increased cylinder, piston and ring wear. It will also contaminate your oil more quickly.

It is not like there are gallons of gas going into the cylinder when you twist the throttle. A small squirt is put in to the intake manifold and may get in to the head. It is really the same principle as a squirt of starting fluid. I guess if you keep twisting the throttle you could flood the bike and run in to the cylinder. All a few twists of the throttle does right before starting is get some fuel vapor in to the system. You then immediately hit the starter button and it instantly ignites. No gush of fuel is diluting your oil and even if a little would get through we all change our oil long before it would break down and have an effect.

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With the warmer temps upon us, your the bike will be easier to start, and you may find a system that works. Just don't try the various starting techniques when it's 40 below. ? You will flood your bike, have a dead battery, overheated starter, contaminated Oil, and your leg will be sore from kicking the bike over. I've been there and done that.

Buy a 72 starter jet.

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