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Discussion Starter · #1 ·
Hello,
try to make valve clearance.
cbr250r 2011 55,000 kilometers.

the intake was in specs.
but the exhaust was to tight.
so when I change the shims the clearance not change,iven without shims it stay in the same clearance as it was with the original shims.
its very strange..
what do you think?
 

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Honda: INNOVA125i(2010); CBR250R(2013)
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Hello,
try to make valve clearance.
cbr250r 2011 55,000 kilometers.

the intake was in specs.
but the exhaust was to tight.
so when I change the shims the clearance not change,iven without shims it stay in the same clearance as it was with the original shims.
its very strange..
what do you think?
yes it's strange.
Hi, we already had a discussion here about valve clearance being smaller, and I claimed that I had never heard of a valve clearance being smaller as a result of wear. The other claim was a claim that in sporty riding at high rpm there is wear in the valve seat which causes the valve to come out and close the gap.

As far as I'm concerned, the strange part of the test you conducted begins with the fact that you found a gap in the exhaust manifold valves that is smaller than spec. And as mentioned above, there is the opposite claim.

Regarding the three identical measurements you performed:
  • with old shims,
  • without shims at all,
  • and with new shims,
and you got the same measurement. This is also strange, the equal measurement between two different shims can be explained if they are both the same thickness.
Do you have a micrometer to check the thickness?
As for the measurement without shims at all, a greater gap should have been obtained, only that no one measures it.

Till now adjusting valves is one of the more complicated jobs I've had to do on my cbr250r. The openings at the top of the engine must be blocked to prevent shims from falling into the engine. And there is the matter of gluing the gasket. And the whole access is very inconvenient (I also disassembled the fuel tank so that I could have an access window from above as well).
You need a lot of patience, and work slowly, to avoid mistakes.
I'll look for you the last link that was here on the topic...just a minute
 

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Honda: INNOVA125i(2010); CBR250R(2013)
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And there is this LINK too:
2012 Honda CBR250RA Valve Adjustment - Road and Trail
 
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Honda: INNOVA125i(2010); CBR250R(2013)
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yes id check the shims.

its look like deadlock,and i dont going to pull out cylinder head right now..
I think to put it back with 1.70 and 1.65 instead 1.84(this is what was when I open it).

what do you think?

thank you very much.
Hi and sorry, I'm saying what I already said before.
Adjusting valves with shims, and especially adjusting valves on a CBR250R 2011-2013, considering that this is a routine schedules job, is one of the most difficult job that I have deal with. In my opinion, the manufacturer did not intend for us to do this job when the engine is inside the frame, because:
  • The access to the valves is very difficult,
  • We have four shims, so it is possible to easily destroy the process if we do not work properly and mix the shims (2 for the intake manifold, 2 for the exhaust manifold).
I recommended to you,
  1. Don't rush to make decisions, cover the open engine well, go to sleep, and when you have time and patience go back to work and try to figure out what's wrong.
  2. Or bring the motorcycle to a qualified mechanic with a TOW truck.

There is no point at that moment to "throw" the shims to his places randomly, close the engine head, and hope that the all job operation will be successful.
 
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