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Old May 20th, 2021, 12:48 AM   #1
thrasherblue
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like that?

hey! 02 250R 21K (11K mine since october) got to be harder and harder to start over the last week then just didnt at all. my shop did a compression test idk what the other cylinders read but one had 25psi and the exhaust valve was stuck closed. after they adjusted the valve it read 40psi. i have read in several forums that i need at least 125psi from each cylinder to start? is this enough info to get some opinions, please? imma total newbie and the joy of riding has saved my life. can i save my bike back or is he a goner? thanks for your time!
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Old May 20th, 2021, 05:25 AM   #2
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There's something wrong with the statement "the exhaust valve was stuck closed". If that were true you'd have one or more broken parts. Did the mechanic say this?

Sorry you're having trouble Lora, but welcome to the board!
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Old May 20th, 2021, 09:12 AM   #3
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Somethings off here. A valve stuck closed would not increase compression if it were adjusted. A valve stuck open would. And like Jim stated, a valve stuck closed indicates other problems.

The bike has been running, just getting harder to start gradually. That doesn't match only 25psi or 40psi on a cylinder.

So, what is the shops verdict? Does it start and run?


Maybe they meant the vales were tight and that was causing compression loss, which would make things harder to start.

Maybe they meant 125 psi instead of 25 psi?
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Old May 25th, 2021, 03:55 AM   #4
thrasherblue
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the shop verified the readings again with me

the cylinder was at 25psi then after adjusting it went up to 40psi. no the bike does not start.
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Old May 25th, 2021, 03:58 AM   #5
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oops

after adjusting the exhaust valve which they said was stuck shut. they said they couldn't even get a feeler guage in at first. they said they adjusted it to .04 and got the 40psi reading.
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Old May 25th, 2021, 04:06 AM   #6
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the shop said i have a dead cylinder

and that my bike is toast. not worth repairing or rebuilding.
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Old May 25th, 2021, 05:35 AM   #7
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Quote:
Originally Posted by thrasherblue View Post
after adjusting the exhaust valve which they said was stuck shut. they said they couldn't even get a feeler guage in at first. they said they adjusted it to .04 and got the 40psi reading.
I think that means that the valve clearance was zero... that the gap had closed. That prevents the valve from closing all the way, and makes the compression very low.

It's possible that if it was run that way long enough the valve and the mating seat surface were eroded by the hot gas leaking, so the compression is now low even with the valve clearance adjusted properly. Fixing that would require removing the cylinder head and doing a "valve job", where the valve is reground and the seat repaired.

Assuming my explanation is correct, the cost of that work may be as much as the cost of a good used replacement engine.
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Old May 25th, 2021, 05:52 AM   #8
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As TJ noted, most likely it has "burned a valve" and the head needs to be removed and the valve replaced.

Some additional work may be required, but it doesn't sound like the engine is junk to me - just needs a "valve job".

Depending on a few things, a replacement engine may run in the range of $250 to $500. We sold a good one a while ago for $200 IIRC. It's not something you want to ship.
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Old May 25th, 2021, 07:14 PM   #9
thrasherblue
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thank you!

that is what the shop told me today, too! to the letter! i am thinking four gear heads cannot all be wrong. thank you so much for taking time to help me! you guys ROCK!
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Old May 26th, 2021, 05:32 AM   #10
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I hope you find a solution without too much trouble Lora. Keep us posted!
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Old May 26th, 2021, 10:21 AM   #11
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@thrasherblue had you ever done a valve clearance check during your ownership? At 21K bike should have had 3 during its lifetime. I'll wager never done, and if so...at least not properly.

As exhaust valves tend to tighten (thus requiring compensating adjustment) the importance of the procedure becomes quite obvious.
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Old May 26th, 2021, 04:21 PM   #12
thrasherblue
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it's barely at 21K

hi! my speedo was down for a little while but i believe i kept pretty good track of my miles. if i have miscalculated, its no more than 100 miles over 21K
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Old May 26th, 2021, 04:25 PM   #13
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i got the bike with 10,484 (what my shop calls rode hard and put away wet) miles. i have not done the valve checks unfortunately i was unaware until you told me.
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Old May 26th, 2021, 04:35 PM   #14
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Checking/adjusting valve clearance a vital obligation, as you've now learned after suffering the consequences.
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Old June 3rd, 2021, 07:05 PM   #15
thrasherblue
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hi! i, very nicely and unaccusingly, asked my shop, "if we had known my bike was supposed to have had compression tests done at 6000 mile intervals, would we have done one?"
"no." "how come?" "because of the age of the bike."
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Old June 3rd, 2021, 07:24 PM   #16
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"compression tests done at 6000 mile intervals"

Huh? I'm guessing you really meant *valve clearance* checks?
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Old June 3rd, 2021, 08:47 PM   #17
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Quote:
Originally Posted by ducatiman View Post
"compression tests done at 6000 mile intervals"

Huh? I'm guessing you really meant *valve clearance* checks?
Right. @thrasherblue, a failed compression test shows the result of valves that are so far out of adjustment they they're not closing. You need to check the valve clearances at regular intervals and adjust them to spec to prevent them getting so far out of adjustement that they don't close. Once they're not closing all the way, damage is starting to happen. When a cylinder fires, if a valve is not quite closed fire squirts past the valve, wasting some of the energy, but also eroding the metal of the valve and the seating surface it should close against.

Checking them involves taking off the valve covers and using feeler gauges to check the clearances between the valves and the cam lobes that are epening them. It's in the manual, and also here: https://faq.ninja250.org/wiki/How_do..._the_valves%3F
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Old June 8th, 2021, 10:08 PM   #18
thrasherblue
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i freaking love intelligent men!!! thank you so much for sharing your knowledge with me!
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