1970 R60/5, ticking that comes and goes

[wendell]

Hi,
Just got a 1970 R60/5. It's my first BMW, so before I open it up it seems prudent to ask for a little direction. The left cylinder is making a ticking sound that reminds me of a sticky lifter on a car engine. It is most pronounced at 25% to 50% throttle, but disappears at full throttle. The PO said he adjusted the valves, but I can't vouch for his abilities. I am comfortable working on engines, and I have an official service manual and the Clymer. Any help much appreciated!

 

[20774]

Welcome to the forum! I'd certainly recheck the valve clearances, and specifically see how much the rocker arm moves up and down when setting the valves on each side. The only movement you should see is slight and the oil film may move back and forth. The rocker blocks can be squeezed together to eliminate that.

If that's not it, might want to try a mechanics stethoscope when the noise is present at idle and see if you can pinpoint where it's coming from. If the heads were ever off and head gasket changed, the gasket might have been put on wrong and the pushrod is rubbing on the edge of the gasket.

 

[wendell]

Thanks! I'm taking the wheels off today to take to the shop for new tires -- current Metzelers are 16 years old. Putting new brake shoes on too. I'll be back on the cylinder in a couple days and will report back.

 

[gator]

I had this exact thing on my 73 750/5. Turned out to be a valve lifter had cracked. When it finally broke it took out the whole bottom end. My advice check your lifters. New crank and all new bearings and oil pump is expensive!
Gator

 

[wendell]

I had this exact thing on my 73 750/5. Turned out to be a valve lifter had cracked. When it finally broke it took out the whole bottom end. My advice check your lifters. New crank and all new bearings and oil pump is expensive!
Gator

Thanks! I'm spending today researching lifters. It looks like if I catch this early it might not be a huge problem.

 

[wendell]

Welcome to the forum! I'd certainly recheck the valve clearances, and specifically see how much the rocker arm moves up and down when setting the valves on each side. The only movement you should see is slight and the oil film may move back and forth. The rocker blocks can be squeezed together to eliminate that.

If that's not it, might want to try a mechanics stethoscope when the noise is present at idle and see if you can pinpoint where it's coming from. If the heads were ever off and head gasket changed, the gasket might have been put on wrong and the pushrod is rubbing on the edge of the gasket.

Thanks much. Took off the wheels yesterday (new tires & brake shoes) and discovered that the rear axle pinch bolt was only hand tight. I noticed a drop of fluid on the driveshaft fluid drain bolt and discovered it was hand tight as well. So now that I have ample reason to doubt the PO's wrenching skills, I'll definitely be going over all his work, which includes the valve settings.

 

[20774]

Trust but verify!

 

[69ZEFF65]

While the wheels are off for tires pop the valve covers off and check the PO's recent valve adjustment work. A couple loose lock down nuts and drain plugs might be a sign he missed some things. The original post seems to indicate a valve adjuster lock nut may have been missed and it could be an easy fix before the wheels are back on.

 

[wendell]

While the wheels are off for tires pop the valve covers off and check the PO's recent valve adjustment work. A couple loose lock down nuts and drain plugs might be a sign he missed some things. The original post seems to indicate a valve adjuster lock nut may have been missed and it could be an easy fix before the wheels are back on.

Thanks, in fact it was the opposite. All the valves were so tight it was obvious that he never adjusted them, or did it after drinking a quart of ATF. I went ahead and corrected the right-hand side, but didn't bother with the left (the ticky side) because I'm probably going to take the rocker blocks/cylinder head off and look at the lifters. Was going to do it tonight but I don't have a tool that will deal with the exhaust header. I did order one though. I also ordered new pushrod seals as they looked slightly weepy, but can I reuse the cyl head gasket if it looks good? That's a no-no with most other bikes but this is my first Airhead project.
Oh, and I just noticed, no hose clamps where the (new) fuel lines meet the carbs. Sheesh!

 

[69ZEFF65]

You can't reuse the head gasket! The fuel lines are not under pressure, so long as there is a very snug fit you don't need hose clamps. If feel better use clamps by all means get some and stick them on.

 

[20774]

Be careful taking the large nut off the end of the header. The threads tend to gall (gaul??) if they haven't been serviced correctly. When initially put on, a copious amount of anti-seize should have been used, and then typically once every year or two the anti-seize needs to be renewed. If this hasn't been done, be careful. Try taking the nut off. If it moves easily at first and then becomes harder to move, stop and damage is about to happen. At that point, mostly all you can do is cut the nut off. Possibly thorough soaking with Kroil will help the situation...try that ahead of time and let it sit.

 

[swall]

Just cut those exhaust header nuts off.

 

[wendell]

Be careful taking the large nut off the end of the header. The threads tend to gall (gaul??) if they haven't been serviced correctly. When initially put on, a copious amount of anti-seize should have been used, and then typically once every year or two the anti-seize needs to be renewed. If this hasn't been done, be careful. Try taking the nut off. If it moves easily at first and then becomes harder to move, stop and damage is about to happen. At that point, mostly all you can do is cut the nut off. Possibly thorough soaking with Kroil will help the situation...try that ahead of time and let it sit.

Thanks, I probably would have tried to muscle it off. I did a quick search and guess I'll try the ATF/acetone mixture as I have both of those already. If that doesn't work I'll cut.

 

[wendell]

You can't reuse the head gasket! The fuel lines are not under pressure, so long as there is a very snug fit you don't need hose clamps. If feel better use clamps by all means get some and stick them on.

Thanks. Def feel better with the clamps. I have some braided steel line from another bike project but it's only 5mm ID and apparently I need 7mm. Too bad, braided steel would have looked nice.

 

[stevenrankin]

I have been off line for a bit, so late on answering. The head gasket can't be reused.

As far as the exhaust header nuts, they can appear to be welded on due to lack of torque needed to start turning them sometimes. It is awkward to apply a lot of torque to the tool. Nine times out of ten, they just need a tap on the tool handle with a soft hammer to get them started. At that point, care is needed to be sure they are coming off smoothly. Soaking them will not hurt at all, but before cutting try tapping. Yep, put on a lot of never seize when reinstalling them.
As for the noise, LOL, as written verify. Previous owners are known to infect new owners with their bad habits and sloppy work. I think you will find that after you have done a good valve adjustment, things will be fine, not saying don't inspect. things while you have them apart but broken lifters are pretty rare.

Anyway, good luck and good hunting. St.

 

[wendell]

I have been off line for a bit, so late on answering. The head gasket can't be reused.

As far as the exhaust header nuts, they can appear to be welded on due to lack of torque needed to start turning them sometimes. It is awkward to apply a lot of torque to the tool. Nine times out of ten, they just need a tap on the tool handle with a soft hammer to get them started. At that point, care is needed to be sure they are coming off smoothly. Soaking them will not hurt at all, but before cutting try tapping. Yep, put on a lot of never seize when reinstalling them.
As for the noise, LOL, as written verify. Previous owners are known to infect new owners with their bad habits and sloppy work. I think you will find that after you have done a good valve adjustment, things will be fine, not saying don't inspect. things while you have them apart but broken lifters are pretty rare.

Anyway, good luck and good hunting. St.

Yeah, I was ready to start that disassembly, especially because I figured too-tight valves were an unlikely source of all that noise. But after reading your post I decided to do the valves on that remaining cylinder, button everything up and see how it sounds. I did the exhaust valve first. Then I put a socket on the intake valve lock nut, and it was not tight at all. I set the clearance, locked it down, got everything back together and hit the starter. So far, no ticking! Just the normal metallic whirring of valves doing their jobs. That loose lock nut must have been the problem. At least I hope it was. I could only run it in the garage because both wheels are off for new tires and brakes.

As for the rarity of broken lifters, you're probably right. Reading forum posts, It's easy to become convinced that things like that are a bigger problem than they really are -- after all, no one posts about how great their valve lifters are doing.

Thanks for posting, you saved me a bunch of work. Now all I have to do is get the wheels and brakes back on and I'll be ready for autumn!

 

[stevenrankin]

LOL, I love the comment about forums, but in a way you are correct, people mostly write when there is a problem.
As far as I go, I am lucky to have a dedicated small airhead shop to hang out at weekly. So I get the added benefit of not only solving my own issues but I get to see some wild issues that happen to other people.
So far, I find the biggest issue with airheads is what I have coined the phrase "Previous Owner's Disease". LOL, stuff comes into the shop and I have worked on a few new to me airheads where the previous owner was to a degree lazy or downright stupid. The PO unload the sweet looking bike full of a lot of hidden issues.
A good example is a bike I helped the new owner sort where the PO had installed turn signals on the fork legs and when doing so used the wrong diameter bolts because the crap LED signals mounting bracket holes were too small for the proper bolts. It amazed me that someone would be so stupid as to compromise the front suspension for good looks. LOL.

Rambling done, better to ride in the riding season than to work on it. Have fun, St.

 

[rick16]

While you have the wheels off, you could re-grease the wheel bearings (confirming correct preload) and lube the rear drive splines....

 

[wendell]

While you have the wheels off, you could re-grease the wheel bearings (confirming correct preload) and lube the rear drive splines....

Definitely. The bearings looked good and greasy but the splines less so.

 

[stevenrankin]

Wheel spline lube and transmission input shaft spline lube are sometimes the two most neglected things on airheads. I always clean and lube my wheel splines after a tire change. Every 40K I do the splines on the trans.

LOL, I bought a jar of lube from EME that has lasted me quite awhile now. St.