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Valve Adjustment bolt out of travel

gregflyn
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Joined: Sat Aug 20, 2022 12:07 pm

Valve Adjustment bolt out of travel

Post by gregflyn »

Hi. New here.

I’m sorry if this has been addressed elsewhere, I looked but couldn’t find anything.

Short story long 😳. I’ve owned my R60/5 for 7-8 years now and it has been a trooper. Just starts and runs on down the road. It has always had a slight valve tap when hard acceleration. Sounded like the exhaust on the left side. I chatted to a couple guys from Airheads Club and they mentioned that /5 have noisy valves, and not to worry toooo much. I don’t run the bike hard just putter around town.

I recently had the bike in a local shop to work on my clutch, and when I got it back I decided to check the valve adjustment. All 4 adjusters were past the usable travel on the thread, so the lock nuts don’t get enough thread to lock and the threads on the end had all been stretched. I bought and replaced the adjuster bolts, but again they were past there usable travel. So I stretched the threads a bit. I bought a couple new pushrods, to check if my pushrods were the correct length. My pushrods are fine, see photo. On the left side I have now flipped the lock nut to the inside of the rocker arm and can now set the clearance, but I doubt this is recommended. See other photos.

Any suggestions on the cause of this? As mentioned it is all 4 valve adjustment, so not a single failed part. And the bike runs fine.
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cwf
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Re: Valve Adjustment bolt out of travel

Post by cwf »

You might have a bit of this :

The valve seat can also wear, meaning the valve comes further out, reducing the gap until, I suppose, there's no adjustment left. Lead in petrol used to lubricate the valve/valve seat join.

Valve noise can also come from end play on the rockers. I used to clamp them gently while doing up the head bolts.

Charlie.
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schrader7032
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Re: Valve Adjustment bolt out of travel

Post by schrader7032 »

Charlie -

I initially thought that too, but then it didn't make sense. If the valve seat/face is wearing, the valve is coming further and further out of the head. That pushes up on the rocker arm which then pushes down on the other side. Wouldn't more and more threads be showing if the valves were wearing out? I guess I must be missing something... :?:
Kurt in S.A.
'78 R100/7 '69 R69S '52 R25/2
Fast. Neat. Average. Friendly. Good. Good.

gregflyn
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Re: Valve Adjustment bolt out of travel

Post by gregflyn »

As mentioned I initially thought it was the rockers beating the pushrods shorter. The theory of valve wear has merit because it would wear evenly. But as Schrader mentions, it would be going the wrong way. The bike has 22k miles on it. I also thought the cam followers could be wearing. But we are talking 4-6mm!3/16-1/4” to exceed the travel. So it isn’t the cam shaft. Thought some smart dude added 2 head gaskets for safety.

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cbclemmens
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Re: Valve Adjustment bolt out of travel

Post by cbclemmens »

Greg:

One possible cause is the rocker arm assemble is not tight on the head, or the rocker arms are worn. Take the push rods out and see if there is slack in the rockers or shafts.

Another possible cause is wear on the cam and lifters. That would be unusual at only 22K miles unless the previous owner was running too thin an oil. (Wear on the valve seats would reduce the gap.) Unfortunately, fixing the cam lifters would require tearing the engine down, and as long as it is running good I wouldn't do that yet. If it really bothers you, consider grinding the valves and seats, and/or shaving a couple of thousands off the heads. Both of those will give you a little bit less clearance. Another solution would be to find some longer push rods, but I don't know where you would look - maybe a cam shaft manufacturer. But check those rocker arms first.



Good luck

Craig

gregflyn
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Re: Valve Adjustment bolt out of travel

Post by gregflyn »

Thank you Craig.

Lots of food for thought. I have a new set of valve adjuster screws on the way. I will be installing them when they arrive. I’ll look then.

I’m mostly concerned that I’m doing more damage than anything. With the locknuts flipped to the bottom of the rocker arms on the left side I can get and lock in the correct clearance and engine is running better than ever.

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cbclemmens
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Re: Valve Adjustment bolt out of travel

Post by cbclemmens »

Greg;

Looking at your photos again I think I may see your problem. I think your rocker arm shaft may be on upside down. Look in the photo. (I tried to copy it here) The square metal boss that holds the shaft has the thick side close to the head and the thin side away from the head. I'm thinking that if you reversed that and put the thin side close to the head you would get all your adjustment space back. Check the other side and see if it's the same.

Craig
R60-5.jpg

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schrader7032
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Re: Valve Adjustment bolt out of travel

Post by schrader7032 »

Craig -

Not sure I understand your observation. But here's a similar picture of my /7 rocker arms when I did a top end a while back. My picture and the original pictures seem to be the same.
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Kurt in S.A.
'78 R100/7 '69 R69S '52 R25/2
Fast. Neat. Average. Friendly. Good. Good.

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srankin
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Re: Valve Adjustment bolt out of travel

Post by srankin »

Thought some smart dude added 2 head gaskets for safety

I take it you are not the original owner? If you are not, welcome to the world of Previous Owner's Disease. Sadly unless you know the previous owner very well, you won't know what they mucked up on the bike before selling it to you.

Did someone at one time add a thicker base gasket in order to lower compression and reduce pinging?

I am looking at the pictures and don't see anything out of place. The valves look good. If the seats were bad, I would expect to see damage to the valves as well. Kurt's picture of his head is correct and the orientation of the bike in question's valve assembly looks correct.

I find it hard to believe cam or lifter wear would be the cause at 22K miles. Even oil without ZDP in it for solid lifters would not have that much wear in so short a time. Improper oil, I would think, would also fry bearings in the crank.

Adding a thicker base gasket moves everything outward, is my theory. A lot of things were done to bikes back in the day to combat pinging. If you are not the only owner, perhaps the previous owner thought one base gasket of such and such a thickness is good, I will be safe and install a thicker gasket. LOL, like installing two head gaskets?

Where are you located, if close to Rochester NY I could lend a hand or put you into contact with a airhead shop. St.
Owner of a 84, R80RT and 78, R100RS

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cbclemmens
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Re: Valve Adjustment bolt out of travel

Post by cbclemmens »

Thanks Kurt;
Your photo also shows the thick side adjacent to the head - eliminating the possibility that I suggested. I was about to pull the valve cover on my R75/5 to check it. You saved me that effort.

Another possibility is that the rocker arm is worn down where it contacts the valve stem or the valve stem itself is worn down. There again at 22K miles not likely.

Still check that assembly and make sure it's all tight.

Craig

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