valve adjustment question

AdventureDad · 10-17-2016, 05:32 PM

Valve adjustment question.... I have about 1700 miles on mine. I checked the valves at 500, and around 900 miles. No adjustments needed, either time. Now, I've been riding it pretty hard since then. I noticed when warm, and I kill the engine, on a trail or whatever, it takes longer to start up...have to hit the button 2 or 3 times some times, not all. Everything else is A-OK. Would it be worth it to inspect them again? Cold starts are fine. Power is "normal."

I forgot, and searched, but couldn't find what the hallmarks of tight valves are.

DanKearney · 10-17-2016, 06:50 PM

If the valve tappets are way-tight, the valves can leak. That would cause hard starting and stalling when you roll up to a stop.

Have you got a compression tester? That would be a quicker check than tearing things apart to check the clearances again.

Cheers,

Dan K.

jbfla · 10-17-2016, 06:55 PM

The signs of tight valve clearance are hard starting and a lack of power.

However, the clearance on my exhaust valves went to zero, and the bike demonstrated none of those symptoms.

The zero clearance resulted in damage to the cam lobes, which was considered to be my fault for not checking the clearance, and is not covered by the warranty.

To their credit, CSC replaced the cam as a gesture of "good will".

If you are concerned in the least, I would check them again.

jb

pyoungbl · 10-17-2016, 07:31 PM

I'm not sure how one would check compression on the NC250 engine since they come with an automatic compression release. With that said, I'm taking an incremental approach to the valve checks. I did the first check at 685 (all tight), then at 2384 (intakes OK, exhaust tight @ much less than .004") I set them at .08MM this time. So, at about 1500 miles mine needed adjustment. I'll go 2K next time, figuring that the metal parts are settling in, and I am now running the engine oil hotter so it does not have so much fuel in it. If the next check is OK I'll take it out to 3K. Joe and others seem to do just fine with 5,000 miles without a check. Maybe I'm just anal.

Peter Y.

AdventureDad · 10-17-2016, 09:28 PM

I am the king of anal. (I'm sure it sounds totally unlike how I meant that) But I've yet to adjust my valves, and at 1700 miles, they may be settled in a bit. The bike has normal power, and isn't stalling unless I kill it. Riding trails with my skill set and the stock gearing is a recipe for killing the engine.

I'll double check the valves again. My oil level has risen, so I'm sure it's time to get the gas/oil mix out and replace with some 20-50w.

NoVa Rider · 10-18-2016, 05:35 AM

I find it hard to just "check" the valve lash on the RX3. The feeler gauge is so thin I find it hard to slide into place. I just loosen the adjuster nut/screw, position the gauge, set the lash and tighten the lock nut, making sure I still have just the right amount of drag as I pull the gauge out. I pay attention to the orientation of the slot on the adjuster to see if it's changed. That gives me an indication whether the lash increased or decreased. But when I read a post that says an owner checked the adjustment but did not reset, I wonder "how did you manage to do that?" Just my approach.

But to Adventure Dad's question, if valve lash was correct at 500 and at 900 miles, I personally would assume things were fine until next recommended check.

SpudRider · 10-18-2016, 08:35 PM

Quote:

Originally Posted by AdventureDad

Valve adjustment question.... I have about 1700 miles on mine. I checked the valves at 500, and around 900 miles. No adjustments needed, either time. Now, I've been riding it pretty hard since then. I noticed when warm, and I kill the engine, on a trail or whatever, it takes longer to start up...have to hit the button 2 or 3 times some times, not all. Everything else is A-OK. Would it be worth it to inspect them again? Cold starts are fine. Power is "normal."

I forgot, and searched, but couldn't find what the hallmarks of tight valves are.

Quote:

Originally Posted by jbfla

The signs of tight valve clearance are hard starting and a lack of power.

However, the clearance on my exhaust valves went to zero, and the bike demonstrated none of those symptoms.

The zero clearance resulted in damage to the cam lobes, which was considered to be my fault for not checking the clearance, and is not covered by the warranty.

To their credit, CSC replaced the cam as a gesture of "good will".

If you are concerned in the least, I would check them again.

jb

I agree with JB. Your difficulty starting the engine is most likely caused by tight valves. I have ridden my RX3 over 20,000 miles, and the intake valves have not yet stabilized. I check valve lash every 2,000 miles, when I change the engine oil, and my intake valves always require adjustment. Fortunately, the exhaust valves stabilized after about 15,000 miles.

AdventureDad · 10-18-2016, 10:50 PM

Thanks all. I'll get into it in the next few days. Also, I found it easy to check them without adjusting them. Not a problem. Also, long time, no see, Spud! Welcome back ?!

SpudRider · 10-18-2016, 10:57 PM

Quote:

Originally Posted by AdventureDad

Thanks all. I'll get into it in the next few days. Also, I found it easy to check them without adjusting them. Not a problem. Also, long time, no see, Spud! Welcome back ?!

Thanks for the kind words, Dad. Yes, the colder weather has returned me to the computer. I had a wonderful tire riding all my motorcycles this summer, but it will soon be time to 'hibernate' for the winter, and that means more time at the keyboard.

AdventureDad · 10-18-2016, 11:37 PM

I'm jealous!!! Summer riding in the south sucks. I, for one, missed your presence and guidance. I am pretty sure I speak for others.

SpudRider · 10-19-2016, 01:32 AM

Once again, thanks for the kind words. Members such as yourself make China Riders a nice place to hang out.

Here are several photograph I took while riding the Tour of Idaho 2 (TID2) this summer.

10-17-2016, 05:32 PM	#1
AdventureDad Join Date: Apr 2016 Location: South Mississippi Posts: 253	valve adjustment question Valve adjustment question.... I have about 1700 miles on mine. I checked the valves at 500, and around 900 miles. No adjustments needed, either time. Now, I've been riding it pretty hard since then. I noticed when warm, and I kill the engine, on a trail or whatever, it takes longer to start up...have to hit the button 2 or 3 times some times, not all. Everything else is A-OK. Would it be worth it to inspect them again? Cold starts are fine. Power is "normal." I forgot, and searched, but couldn't find what the hallmarks of tight valves are.
	0

10-17-2016, 06:50 PM	#2
DanKearney Join Date: Jul 2009 Posts: 216	If the valve tappets are way-tight, the valves can leak. That would cause hard starting and stalling when you roll up to a stop. Have you got a compression tester? That would be a quicker check than tearing things apart to check the clearances again. Cheers, Dan K. __________________ Dan Kearney - Black Hawk, Colorado, USA Dan's Motorcycle Blog - "Lost? I'm not lost. I'm just exploring. . ."
	0

10-17-2016, 06:55 PM	#3
jbfla Join Date: Oct 2015 Location: FL, GA, NC Posts: 771	The signs of tight valve clearance are hard starting and a lack of power. However, the clearance on my exhaust valves went to zero, and the bike demonstrated none of those symptoms. The zero clearance resulted in damage to the cam lobes, which was considered to be my fault for not checking the clearance, and is not covered by the warranty. To their credit, CSC replaced the cam as a gesture of "good will". If you are concerned in the least, I would check them again. jb __________________ 2016 Honda CB500F......2017 Triumph Street Twin 2014 XT 250........
	1

10-19-2016, 01:32 AM	#11
SpudRider Join Date: Jul 2008 Location: Idaho Posts: 25,054	Once again, thanks for the kind words. Members such as yourself make China Riders a nice place to hang out. Here are several photograph I took while riding the Tour of Idaho 2 (TID2) this summer. __________________ Spud "Never argue with an idiot. He will drag you down to his level, and beat you with experience." Mark Twain 2015 Zongshen ZS250GY-3 (RX3) 2006 Zongshen ZS200GY-2 (Sierra 200) 2005 Honda XR650L 2004 Honda CRF250X 1998 Kawasaki KDX220 Mods made to my Zongshen ZS200GY-2: http://www.chinariders.net/showthread.php?t=6894
	0

10-17-2016, 07:31 PM	#4
pyoungbl Join Date: Feb 2016 Location: Portsmouth, Virginia, USA Posts: 632	I'm not sure how one would check compression on the NC250 engine since they come with an automatic compression release. With that said, I'm taking an incremental approach to the valve checks. I did the first check at 685 (all tight), then at 2384 (intakes OK, exhaust tight @ much less than .004") I set them at .08MM this time. So, at about 1500 miles mine needed adjustment. I'll go 2K next time, figuring that the metal parts are settling in, and I am now running the engine oil hotter so it does not have so much fuel in it. If the next check is OK I'll take it out to 3K. Joe and others seem to do just fine with 5,000 miles without a check. Maybe I'm just anal. Peter Y.
	1

10-17-2016, 09:28 PM	#5
AdventureDad Join Date: Apr 2016 Location: South Mississippi Posts: 253	I am the king of anal. (I'm sure it sounds totally unlike how I meant that) But I've yet to adjust my valves, and at 1700 miles, they may be settled in a bit. The bike has normal power, and isn't stalling unless I kill it. Riding trails with my skill set and the stock gearing is a recipe for killing the engine. I'll double check the valves again. My oil level has risen, so I'm sure it's time to get the gas/oil mix out and replace with some 20-50w.
	0

10-18-2016, 05:35 AM	#6
NoVa Rider Join Date: Jan 2015 Location: Northern Virginia Posts: 144	I find it hard to just "check" the valve lash on the RX3. The feeler gauge is so thin I find it hard to slide into place. I just loosen the adjuster nut/screw, position the gauge, set the lash and tighten the lock nut, making sure I still have just the right amount of drag as I pull the gauge out. I pay attention to the orientation of the slot on the adjuster to see if it's changed. That gives me an indication whether the lash increased or decreased. But when I read a post that says an owner checked the adjustment but did not reset, I wonder "how did you manage to do that?" Just my approach. But to Adventure Dad's question, if valve lash was correct at 500 and at 900 miles, I personally would assume things were fine until next recommended check.
	0

10-18-2016, 10:50 PM	#8
AdventureDad Join Date: Apr 2016 Location: South Mississippi Posts: 253	Thanks all. I'll get into it in the next few days. Also, I found it easy to check them without adjusting them. Not a problem. Also, long time, no see, Spud! Welcome back ?!
	0

10-18-2016, 11:37 PM	#10
AdventureDad Join Date: Apr 2016 Location: South Mississippi Posts: 253	I'm jealous!!! Summer riding in the south sucks. I, for one, missed your presence and guidance. I am pretty sure I speak for others.
	0