CRF250R 2016 valve help

Owen2020
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Owen2020
Edited Date/Time 9/17/2022 4:13pm
Hello all,

See photos below, are my intake valves worn?

Having issues with hard starting especially when warm. And rough idling.




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willbilly
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willbilly 9/16/2022 12:32pm
9/16/2022 12:32pm
The valve seats look to be cupped to me. I would replace and have the seats cut.
willbilly
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willbilly 9/16/2022 12:35pm
9/16/2022 12:35pm Edited Date/Time 9/16/2022 12:36pm
The valves look to be cupped to me. I would replace and have the seats cut.
Owen2020
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Owen2020 9/16/2022 12:53pm
9/16/2022 12:53pm
willbilly wrote:
The valves look to be cupped to me. I would replace and have the seats cut.
Thanks for the reply, would this cause the valve not to seat properly and have an idle issue?
Factor E
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Factor E 9/16/2022 3:28pm
9/16/2022 3:28pm Edited Date/Time 9/16/2022 3:30pm
Looks as one not sealing
Guessing the intake shims are very thin
Total rebuild of head
Don't bandage it

The Shop

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willbilly
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willbilly 9/17/2022 4:13pm
9/17/2022 4:13pm
Could cause idle problem. Did you check the valve clearance before removing the valves? If they were zero the valves never completely close. What Factor E is suggesting is the wear may be too much to just cut the seats and replace valves. What size shims were installed? If they are the thinnest or close to thinnest you will need the valve seats replaced. If that’s the case a rebuild of the head (Valve seats replaced, valve guides replaced) will run about $450. Plus new valves, springs, keepers/cotters.
Owen2020
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Owen2020 9/17/2022 10:15pm
9/17/2022 10:15pm
willbilly wrote:
Could cause idle problem. Did you check the valve clearance before removing the valves? If they were zero the valves never completely close. What Factor E...
Could cause idle problem. Did you check the valve clearance before removing the valves? If they were zero the valves never completely close. What Factor E is suggesting is the wear may be too much to just cut the seats and replace valves. What size shims were installed? If they are the thinnest or close to thinnest you will need the valve seats replaced. If that’s the case a rebuild of the head (Valve seats replaced, valve guides replaced) will run about $450. Plus new valves, springs, keepers/cotters.
I’ve just ordered new valves, I did the gasoline trick and poured into the intake side and one valve was leaking.

The shims were a 1.60 and 1.65.

Clarence should be 0.12-0.15mm i could fit a 0.18m passed on the leaking valve side. So I put a 1.65 in but then one side was too tight!

I’ve got the hot cam shim kit which goes up and down at 0.5mm.

What I did notice is the valve stems were quite low indicating wear… the seats look absolutely fine with no damage. I’ll see how it goes when the new valves arrive

Paul_Pitzonka
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Paul_Pitzonka 9/18/2022 12:37am
9/18/2022 12:37am
willbilly wrote:
Could cause idle problem. Did you check the valve clearance before removing the valves? If they were zero the valves never completely close. What Factor E...
Could cause idle problem. Did you check the valve clearance before removing the valves? If they were zero the valves never completely close. What Factor E is suggesting is the wear may be too much to just cut the seats and replace valves. What size shims were installed? If they are the thinnest or close to thinnest you will need the valve seats replaced. If that’s the case a rebuild of the head (Valve seats replaced, valve guides replaced) will run about $450. Plus new valves, springs, keepers/cotters.
Owen2020 wrote:
I’ve just ordered new valves, I did the gasoline trick and poured into the intake side and one valve was leaking. The shims were a 1.60...
I’ve just ordered new valves, I did the gasoline trick and poured into the intake side and one valve was leaking.

The shims were a 1.60 and 1.65.

Clarence should be 0.12-0.15mm i could fit a 0.18m passed on the leaking valve side. So I put a 1.65 in but then one side was too tight!

I’ve got the hot cam shim kit which goes up and down at 0.5mm.

What I did notice is the valve stems were quite low indicating wear… the seats look absolutely fine with no damage. I’ll see how it goes when the new valves arrive

With the valve face that worn you can bet the valve seat is that worn as well... and with a 1.60 shim already you’ll more than likely need the seats replaced rather than just recut...
Rickyisms 9/18/2022 8:42am
9/18/2022 8:42am
Like Factor E said don’t bandage it. Do it right or do it twice.

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