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charles50

08 CRF250R Hard to Start!

28 posts in this topic

I just bought a CRF250R. I rode three days. Day one, I burnt a tank of gas to break in the motor. Then, rode second day and had problems starting it after it was idleing and stalled during warm up. Day 3, the motor ran well and no problems. Then on the 4th day I had alot of problems starting it, after kicking for a while and leaving it sit, I finally got it started. I dont no why it is so hard to start sometimes. I dont think it is a valve problem since it is so new. It's almost like the carb floods easy. I still have stock settings. Any suggestions?

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They do flood very easily, When you kick it over (if you're new to CRF's or 4-strokes in general) put your right hand on the crossbar pad when starting it. I've seen so many people that think theyre not giving it any gas and just the teeniest little roll of the throttle and the bike squirts some and they think their bike is a pile.

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I dont think its an issue with me giving gas when i start since i had a 2007 Ktm250sxf last year and an 04 Crf250R 2 years before that. I have dealt with 4 strokes alot before and these bikes have never been this difficult to start as the 08 CRF

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My son has the exact same problem. I have a crf450, starts first 2-3 kicks, my son had a crf150r always started first 2-3 kicks but this 08 250 just will not start very easily. I've changed the pilot jet to a 45 and it helped a little. My son was way out in front at a race this past weekend and killed it and ended up with a dnf. :p I know that's the way 4 strokes are but we never had a problem with previous 4 strokes. :eek:

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this hard starting thing with the 08' seems to be VERY common....there HAS to be a fix....anyone??

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I just bought a CRF250R. I rode three days. Day one, I burnt a tank of gas to break in the motor. Then, rode second day and had problems starting it after it was idleing and stalled during warm up. Day 3, the motor ran well and no problems. Then on the 4th day I had alot of problems starting it, after kicking for a while and leaving it sit, I finally got it started. I dont no why it is so hard to start sometimes. I dont think it is a valve problem since it is so new. It's almost like the carb floods easy. I still have stock settings. Any suggestions?

i would STILL check the valves, because it new is no escuse, it happens alot to people where the valves can go out of spec in a little but off the floor

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A friend and both purchased 250's at the same time and both bikes are very hard to start. I'll check the valve clearance tonight but I find it hard to believe thw clearance could be off in both bikes with less than 10 hrs on them.

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Check the valves, they do seat in during break in. Set them to .005 intake and .011 exhaust.

As for the bike being hard to start, yes they can be. I have had troubles with mine, but I find now that I have close to 40 hrs of ride time (just about to put in my high compression piston) that I have started to get the right technique.

They do flood easily. If it is not starting, turn off the choke, full throttle and hot start for a few kicks to clear it out, then zero throttle, no choke, and hotstart, keep kicking until it does start. Make sure you are at top dead center, and you give it a good smooth strong kick.

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As for the jetting, use a 45 leak jet, 168 main jet if you are above 1500 feet, and a 172 if you are below 1500 feet. Stock is 188 which is way to rich. And then set your fuel screw properly. Turn it in until the bike idles down, then turn it out until it idles the highest/runs the best. Test by blipping the throttle. And make sure you idle isn't too low.

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I checked the valves, Intake is right on the money .005 exhausts were .009, .010.

I do notice the pipe has black soot like it is running rich I may drop down on the main and see what happens.

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dropping down on the main will have no bearing on how the bike starts up

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The correct size main jet, either the 168 or 172 gives you a 1 HP boost of power. It does affect how the bike runs. Ron Hamp has proved this on his dyno.

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The correct size main jet, either the 168 or 172 gives you a 1 HP boost of power. It does affect how the bike runs. Ron Hamp has proved this on his dyno.

Yes, this is true. But, main jet changes will NOT affect how the bike starts. The pilot circuit (pilot jet, fuel screw, and starter jet [when using choke]) will affect the fuel delivery when kicking it over, with the throttle closed.

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Not meaning to start an argument, I was just stating that the different main jet does affect how the bike runs. I didn't say it affected how it started because the main jet controls 1/2 to full throttle.

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I agree about the main not helping the starting issue, I was going to drop down the main because of the black soot in the exhaust and leave it alone and see if it gets better after we ride a little longer. I may play with the pilot and try going up another size.

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As said before, the pilot circuit is your problem, probably. But also when you wash your bike, water some times enter all wierd places, so drain your float bowl, one single small drop of water can F-up your starting procedure badly. Just the big bolt in the bottom of the bowl, drain it, empty the bolt and so on.

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I too had a problem with starting. I shimmed the valves (they were tight), installed an R&D power pump and adjusted it to a #45 leak jet equivalent.

Gave the throttle 2 full twist, it fired. Before this it was almost impossible to start.

As far a jetting I am running a 172 main, the rest is stock and my pipes are still black at the tips.

Any thoughts, should I lean out the needle?

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You will always get a bit of black carbon on the end of the pipe. I wouldn't worry about it unless it is excessive. The 172 main jet should be fine for you if you are 1500 feet or below in elevation, if you are higher than 1500 feet I would use a 168 main jet. I am using the 168 main at 2100 feet and the sparkplug has a nice color to it. So I am happy with the jetting settings that I posted earlier.

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