Valve spec way to loose

[surfandskim92]

I bought a 2007 kx250f last week. I took it out for 2 rides so far. Both times the bike starts when cold, but after an hour of riding it, when I go to start it back up I can't get the bike to start back up. So I checked the valves. My intake should be 10-15 and I have 11 on left and 16 on right, although my exhaust should be 17-22 and I have 26 on left and 28 on right. Everything I have come across on the fourms says anything about it being this far off. I have already ordered shims to try and re shim. But After reading about seat cutting I am worried the previous owner may have done something wrong. I just don't know what else to look for or to check. Or why the exhaust clearance is so loose and if this would make the bike hard to start. Thanks in advance.

[Wild Alaskan]

with those measurements the valves are not your problem. Look at carburetor and technique.

[surfandskim92]

Even tho the exhaust is well loose of spec? This is my first time doing a valve adjustment. Thanks

[Wild Alaskan]

loose is uncommon, I would double check the measurements, but it will mostly result in a noisy valve train and these are not far enough off to effect starting. I'm guessing the measurements you are giving is in tenths of millimeters?

[surfandskim92]

My feeler guages say mm, so 26mm and 28mm for the exhaust. I have not found anything anywhere of anyone having that loose of valves. Yet I did the same thing for my intake and those are in spec. I will review everything again tomorrow but I did a lot of research on how to adjust valves so I am pretty sure I did it correctly

[Doc_d]

No offense but if you think the clearance is 26mm/28mm I think you should get someone to help you check the clearances before you make any adjustments just to be sure.  26mm is about 1 inch.  You don't have 1 inch of valve clearance.

 

Valve clearances that are too large don't affect starting.  They'll cause a noisy valve train and wear out your valves faster.  

Edited January 19, 2016 by Doc_d

[ToadalyCrazyCanadian]

I think you mean0.26 and 0.28mm

[JoeRC51]

I think you mean0.26 and 0.28mm

 

multimeter ?  

Edited January 19, 2016 by JoeRC51

[ToadalyCrazyCanadian]

multimeter ?

Millimeter if he is using metric feeler gauges.

[JoeRC51]

Millimeter if he is using metric feeler gauges.

 

I was being sarcastic.

[ToadalyCrazyCanadian]

I was being sarcastic.

Never know. This thread is proof some things need a little extra explaining.

[surfandskim92]

Yes I am sorry. 0.26mm and 0.28mm for the exhaust. And 0.16mm and 0.11mm for the intake. Thanks

[surfandskim92]

So if bigger valves on the exhaust end won't effect starting should I even reshim them into spec ? I guess next thing is to check the carb.

[T-Bone 426]

Spark plug, coil often cause issues once hot . Your valves ain't bad and a bigger gap won't hurt your starting once hot .

[surfandskim92]

I ordered a new spark plug. If I still have issues I will try a new coil

[surfandskim92]

Anyone else have any ideas ?

[surfandskim92]

so I am in the process of shimming my valves and when I removed the buckets I thought the 4 valve circles ( sorry don't know actual name) are suppose to look the same ? The 2 exhaust valves almost seem to have something glued on top of them? Is this normal ? Thanks !

[cptncreme]

Those are the shims

[surfandskim92]

I already removed the shims. I'm talking about the area surrounding the shins. The 2 intake are different then the 2 exhaust

[surfandskim92]