OHC owners beware!

czowner · 10-09-2009, 02:19 PM

I checked my valve clearances today (15k miles), I found they'd closed up to near zero. Last checked and adjusted at 7.5k miles.

Jonathan.

Reveeen · 10-09-2009, 02:43 PM

Hot, or cold?

Hot.....they are supposed to be near 0.

Cold.....I can't imagine it running worth crap hot.

czowner · 10-09-2009, 04:10 PM

Quote:

Originally Posted by Reveeen

Hot, or cold?

Hot.....they are supposed to be near 0.

Cold.....I can't imagine it running worth crap hot.

I checked them cold, left overnight. It was running OK, I think I just caught it in time. The reason I made a point of checking the valves is that a friend had come across a non-running OHC GY, it had closed up valve clearances.

Jonathan.

TheRealWorld · 10-09-2009, 11:39 PM

If you are new to these valve adjustments It is hard to tell if they are tight or not. It is not easy to get that flimsy feeler in there!

czowner · 10-10-2009, 05:02 PM

Quote:

Originally Posted by TheRealWorld

If you are new to these valve adjustments It is hard to tell if they are tight or not. It is not easy to get that flimsy feeler in there!

No offence intended old friend but after 29 years in the motor trade I think I can be trusted to adjust valve clearances. They're not one of the easiest though!

Jonathan.

Q · 10-10-2009, 05:46 PM

On the pushrod engines the valve lash increases as the engine heats up, thus the very tight clearance adjustment. Is it possible that the OHC engines do the same? Would be interesting to compare the hot vs. cold clearances.

Q

TheRealWorld · 10-10-2009, 06:46 PM

No offense taken, But my comments are still accurate and many of us here need all the help we can get. We are glad to have someone who has been at it for 29 years.

czowner · 10-12-2009, 04:43 AM

I might just be imagining things but she seems happier at higher speed, I also changed the DR8EA for a cooler running DR9EA as she has to work hard in my hands!

Jonathan.

forchetto · 10-13-2009, 03:31 PM

I find this a lot on Chinese engines. I've maintained a lot of bikes and the valve clearances have always got bigger, not smaller with time and mileage.

I feel the Chinese alloy casting maybe softer and there's a certain amount of valve seat settlement or "recession". This closes up valve clearances and is the source of lots of trouble on these engines. Just check out other forums...

10-09-2009, 02:19 PM	#1
czowner Join Date: Sep 2006 Location: North East England Posts: 313	OHC owners beware! I checked my valve clearances today (15k miles), I found they'd closed up to near zero. Last checked and adjusted at 7.5k miles. Jonathan.
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10-13-2009, 03:31 PM	#9
forchetto Join Date: Jul 2008 Location: Gijon, Asturias,Northern Spain Posts: 396	I find this a lot on Chinese engines. I've maintained a lot of bikes and the valve clearances have always got bigger, not smaller with time and mileage. I feel the Chinese alloy casting maybe softer and there's a certain amount of valve seat settlement or "recession". This closes up valve clearances and is the source of lots of trouble on these engines. Just check out other forums... __________________ Jincheng Monkey JC50Q-7 (two of them) Skyteam Dax replica ST110-6 (two of them) Zongshen ZS125-43 Qingqi QM200GY-BA Super Motard Yamaha Virago XV1100 Triumph Bonneville SE Qingqi QM110GY PGO Bug rider 250 Buggy
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10-09-2009, 02:43 PM	#2
Reveeen Join Date: Jun 2009 Location: orbital platform Posts: 741	Hot, or cold? Hot.....they are supposed to be near 0. Cold.....I can't imagine it running worth crap hot.
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10-09-2009, 11:39 PM	#4
TheRealWorld Join Date: Jun 2008 Posts: 817	If you are new to these valve adjustments It is hard to tell if they are tight or not. It is not easy to get that flimsy feeler in there!
	0

10-10-2009, 05:46 PM	#6
Q Join Date: Sep 2007 Location: Bend, Oregon Posts: 348	On the pushrod engines the valve lash increases as the engine heats up, thus the very tight clearance adjustment. Is it possible that the OHC engines do the same? Would be interesting to compare the hot vs. cold clearances. Q
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10-10-2009, 06:46 PM	#7
TheRealWorld Join Date: Jun 2008 Posts: 817	No offense taken, But my comments are still accurate and many of us here need all the help we can get. We are glad to have someone who has been at it for 29 years.
	0

10-12-2009, 04:43 AM	#8
czowner Join Date: Sep 2006 Location: North East England Posts: 313	I might just be imagining things but she seems happier at higher speed, I also changed the DR8EA for a cooler running DR9EA as she has to work hard in my hands! Jonathan.
	0