Did I bend my valve(s)?

Michigan Sportsman · 03-02-2022, 10:36 PM

I ratcheted the engine around an few revolutions, aligned the “Tl”, and and adjusted the valve lash. I ratcheted the engine around an few revolutions, aligned the “Tl”, and rechecked the valve lash to find them both tight. So I readjusted the valve lash, ratcheted the engine around an few revolutions, aligned the “Tl”, and rechecked the valve lash to find the exhaust perfect and the intake very loose.

I say to myself… self, this can’t be.

With the “Tl” aligned the valve lash should be consistent. So I ratcheted the engine around an few revolutions, this time observed the action of the valves in relation to the “TI” alignment and discovered there were two different valve positions when the “TI” is aligned.

I adjusted/rechecked them on the correct intake cycle and whalla!

Haven’t started engine since being uncrated. I’m in the process of disassembly/upgrade/qc/threadlock/rust prevention.

Megadan · 03-02-2022, 11:14 PM

Nah, your safe. Good job catching your mistake. It's a very common one to make.

Ol,fart · 03-03-2022, 12:30 PM

Really the only thing you could do is adjust them to loose if the cam was not at the bottom of the lobe.

Michigan Sportsman · 03-03-2022, 12:49 PM

Great, I rarely get away without paying for my education.

For your input!

zero_dgz · 03-04-2022, 08:48 AM

Quote:

Originally Posted by Michigan Sportsman

So I ratcheted the engine around an few revolutions, this time observed the action of the valves in relation to the “TI” alignment and discovered there were two different valve positions when the “TI” is aligned.

This is a very important detail that anyone adjusting their valve lash on any bike should know, and I see glossed over a lot in tutorials for some reason: A four stroke engine has two different possible top dead center positions. The piston reciprocates twice for every complete engine cycle. The piston reaches top dead center on the compression stroke and also the exhaust stroke. When checking/adjusting your valves you want it to be at top center on the compression stroke.

When it's at TDC on the compression stroke both the inlet and exhaust valves are closed. When it's at TDC on the exhaust stroke the exhaust valve is open, and if you try to adjust the valve lash in that state you'll wind up with the clearance on the exhaust valve impossibly wide.

You can determine which is the exhaust and which is the compression stroke on engines where you can't see the cams by watching the valve tappets move as you turn the crank. At TDC on the compression stroke both valves will be fully closed (with the tappets fully raised, both of them equally). On the exhaust stroke the tappet over the exhaust valve will be lowered while the one over the intake valve will be raised.

03-02-2022, 10:36 PM	#1
Michigan Sportsman Join Date: Feb 2022 Location: Avoca, Michigan Posts: 32	Did I bend my valve(s)? I ratcheted the engine around an few revolutions, aligned the “Tl”, and and adjusted the valve lash. I ratcheted the engine around an few revolutions, aligned the “Tl”, and rechecked the valve lash to find them both tight. So I readjusted the valve lash, ratcheted the engine around an few revolutions, aligned the “Tl”, and rechecked the valve lash to find the exhaust perfect and the intake very loose. I say to myself… self, this can’t be. With the “Tl” aligned the valve lash should be consistent. So I ratcheted the engine around an few revolutions, this time observed the action of the valves in relation to the “TI” alignment and discovered there were two different valve positions when the “TI” is aligned. I adjusted/rechecked them on the correct intake cycle and whalla! Haven’t started engine since being uncrated. I’m in the process of disassembly/upgrade/qc/threadlock/rust prevention. __________________ 2021 Hawk DLX 250 2015 Super Hornet 150 2008 Honda VTX1300R 1982 Kawasaki KD80 - (Sold)
	1

03-02-2022, 11:14 PM	#2
Megadan Join Date: Apr 2017 Location: Omaha, NE Posts: 8,020	Nah, your safe. Good job catching your mistake. It's a very common one to make. __________________ Hawk Information and Resource guide: http://www.chinariders.net/showthread.php?t=20331 2018 Hawk 250 - Full Mod list here. http://www.chinariders.net/showpost....62&postcount=1 2024 Royal Enfield Shotgun 650 https://chinariders.net/showthread.php?t=34124
	1

03-03-2022, 12:30 PM	#3
Ol,fart Join Date: Jan 2022 Location: Gatesville Texas Posts: 161	Really the only thing you could do is adjust them to loose if the cam was not at the bottom of the lobe. __________________ 2021 RPS Hawk "IKEA" (Came in a box with no instructions) 110 main jet 1washer,2.5 sprockets and the cat fell off( with a little help) 1984 Honda V65 Magna "Daddy's Little Monster" To whoever stole my anti-depressants. I Hope Your Happy !
	1

03-03-2022, 12:49 PM	#4
Michigan Sportsman Join Date: Feb 2022 Location: Avoca, Michigan Posts: 32	Great, I rarely get away without paying for my education. For your input! __________________ 2021 Hawk DLX 250 2015 Super Hornet 150 2008 Honda VTX1300R 1982 Kawasaki KD80 - (Sold)
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