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02 YZ125 Hard Strating When Not Started Every Couple Days???

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My 02 YZ125 is very hard to start if I don’t use it for a few days.

-If I start it every day it starts first kick every time. If I leave it for more than it seems like 2-3 days I have to kick it about a 100 times to get it going. and then it seems to run lean as soon as I turn off the choke and it wants to cut out until it idles for a minute or two.

-Anyone know what the problem might be? Compression is good and it has a completely new engine along with all gaskets and seals.

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Happened on my RM125 (1995) too. I had to use choke and hold my had over the silencer kind of closing it with my hand. The newer the top end was it did not happen. How many hours has the piston?

There's about 1-1.5 hours on the whole engine.

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There's about 1-1.5 hours on the whole engine.

What? Its an 02, unless you just rebuilt it big time then it cant only have 2 hours.

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What? Its an 02, unless you just rebuilt it big time then it cant only have 2 hours.

As mentioned in the last sentence in my first post… It has a completely new engine along with all gaskets and seals.

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My '03 does the same thing when I come back from college, except mine sits for weeks at a time. It takes like 10-15 kicks to get it going the first time and seems to run strange for a few minutes but after that it seems fine. Mine was also entirely rebuilt about 15 hours ago. I'm going to take the carb apart next time I'm home and clean everything and see if that helps.

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Ok but was the jug replated?

Jug didn’t need replacing it was within spec, I just deglazed it.

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Look at your reeds. Pull them out and see if you can see light through them replace them.

That crossed my mind. I had a sled with the same problem a few years ago and it ended up being a damaged reed cages. But that thing was hard to start every time it cooled down.

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Do you guys think it could be a stuck open power valve? One of them seemed a little sticky the last time I cleaned them.

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Do you guys think it could be a stuck open power valve? One of them seemed a little sticky the last time I cleaned them.

If it was stuck powervalves, you would notice it by having no bottom end.

Do you leave your gas on when the bike sits? I have a theory that a leaking inlet needle valve will slowly let gas in while what gas is in the bowl pukes out the pilot. Then when you give it that first kick, it floods.

Try turning off your gas and run the bike around for 15 seconds before you park it. I wouldn't recommend running it enough to drain the entire carb because it will starve the engine of fresh premix.

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I use gump electrical spray and wipe it with a clean rag. Each 3 months. I lost one cdi because the magneto got wet and dirty. Did not think that I had to have a look into it and lost basically the cdi. We ride here in vert dusty aereas.

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