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Another hard start 07 crf250r

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So I picked up an 07 this spring know it would not start cold or hot but if you bump started it would run. So I checked the valves and left intake was tight and had the smallest shim. Took the head off sent it to MXTime for 4 s.s. Valves springs and have the seats done. From what it looks like the top and bottom where done 46 hours ago. Put it back together and 3rd kick it fired right up. That weekend went to ride and would not start cold most of the time. I could get it to bump start no problem. So I rechecked the timing and the valve clearance. All good. Wired the the auto decomp open checked compression that was over 150 psi if I remember. I have been riding it as is now just having to bump start it. Once it’s warm sometimes I can get it to run by kicking but last weekend I had to bump start it when hot. You can hear if fire a bit but not enough to run. Where do I go from here? Check and clean the carb? When I time it the dots don’t line up perfectly with the head it’s like it’s a half a tooth off either direction. Once the bike is running it runs awesome plenty of power.

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What are your valve clearance numbers ?

Any chance you are mixing up SAE & Metric readings ?

(specs, feeler gauges etc.)

Edited by mlatour

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I second what Mia said about valve clearance. I have see ss valves settle a little and need adjustment. If not I'd clean the carb.

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If I remember I went right to .006 for intake and .012 for exhaust. I have checked them in for awhile. I’ve put about 5 or more hours on the bike since maybe more. If I have time today I’ll check them. Pretty sure I specd them to metric. Thanks guys!

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If I remember I went right to .006 for intake and .012 for exhaust. I have checked them in for awhile. I’ve put about 5 or more hours on the bike since maybe more. If I have time today I’ll check them. Pretty sure I specd them to metric. Thanks guys!


Screw imperial, dumb measurements.
Intake should me 0.13mm and exhaust should be 0.28mm
Anything different and you will have trouble starting it. Also check your getting a strong spark. The plugs tend to wear out.

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I did check the spark and that was good. Even compared to another bike and 2 known good plugs. I guess today I’ll try to set the valves to .13 and .28 thanks!

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I did check the spark and that was good. Even compared to another bike and 2 known good plugs. I guess today I’ll try to set the valves to .13 and .28 thanks!

 

Above you report .006" and .012". Those number are in inches of course and within specification.

 

.13mm = .0051181"

.28mm= .0110238"

 

Assuming you're reading the feelers correctly in the 1st place, and the valves didn't move, that's not your issue.

 

Screw imperial, dumb measurements.

Intake should me 0.13mm and exhaust should be 0.28mm

Anything different and you will have trouble starting it. Also check your getting a strong spark. The plugs tend to wear out.

Idiot

 

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I put the fuel screw to factory settings still no dice. Didn’t have time to mess with it tonight. I appreciate all the help guys!


The factory setting is only a starting point. Every bike is different and it requires adjustment for changes in atmospheric conditions.

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If I roll it down hill and kick some times it will start some times it doesn’t. Same way if I’m riding and stall it. I’ll use the hot start and 1 or 2 kicks it fires. If it doesn’t start within the 2 kicks it usually has to be bumped

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Verify the valves are all in spec. Don't worry about some magic number, if they are in range it's fine.

I don't know your experience level so I'll throw this out there. Are you using proper starting technique? Cold engine- choke on, no throttle. Warm engine- hot start, no throttle. Sometimes if the weather is cold a quick twist of the throttle to squirt a bit of fuel will help but for every other situation, don't give it any throttle. You will flood it.

Check the carburetor. Make sure the condition of the fuel screw and vacuum release plate o-rings are in good shape. Check to make sure the float level is set to around 9mm. Verify the jetting. Blow all passages out with compressed air. Check out Pro Circuit's jetting recommendation list.https://www.procircuit.com/jetting-specs.htm

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Idiot
 


Relax hectic.. dont act like you know anything idiot. You would probably send your bike to a mechanic to get it re-fuel'ed. pathetic garbage

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Verify the valves are all in spec. Don't worry about some magic number, if they are in range it's fine.

I don't know your experience level so I'll throw this out there. Are you using proper starting technique? Cold engine- choke on, no throttle. Warm engine- hot start, no throttle. Sometimes if the weather is cold a quick twist of the throttle to squirt a bit of fuel will help but for every other situation, don't give it any throttle. You will flood it.

Check the carburetor. Make sure the condition of the fuel screw and vacuum release plate o-rings are in good shape. Check to make sure the float level is set to around 9mm. Verify the jetting. Blow all passages out with compressed air. Check out Pro Circuit's jetting recommendation list.https://www.procircuit.com/jetting-specs.htm



Whats all this trash about starting techniques.. everyone with honda knowledge knows that ive valves are even slightly out of spec the bike will only role start

Re-shim your valves bro and i gaurantee it will stsrt first or second kick

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Relax hectic.. dont act like you know anything idiot. You would probably send your bike to a mechanic to get it re-fuel'ed. pathetic garbage


How old are you, 14? I've read your other posts. Did you figure out the hole in your cam or the rattle in your starter yet?

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Hole in my cam was a factory issue as Honda quoted and a replacement was offered to me which i declined as it does not effect the performance of the bike..
As for the kick starter rattle if you so called "read" my other posts you would know that the issue was the bent back plate and i replaced the part. Unlike you people are smart and have usefull and helpful tips. Instead of "have you checked your fuel screw". You're disabled. And my age doesnt concern you..

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Hole in my cam was a factory issue as Honda quoted and a replacement was offered to me which i declined as it does not effect the performance of the bike..
As for the kick starter rattle if you so called "read" my other posts you would know that the issue was the bent back plate and i replaced the part. Unlike you people are smart and have usefull and helpful tips. Instead of "have you checked your fuel screw". You're disabled. And my age doesnt concern you..

Lol, good for you little Abo. Enjoy your time here. Despite your wealth of knowledge and sunny disposition, I suspect your time here will be short if you keep it up.

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Lol, good for you little Abo. Enjoy your time here. Despite your wealth of knowledge and sunny disposition, I suspect your time here will be short if you keep it up.


Little abo? Hahaha ill take it i guess, you're veering away from what i say because your stupid words where used to destroy you..

Idiot

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