• Welcome, Guest! We hope you enjoy the excellent technical knowledge, event information and discussions that the BMW MOA forum provides. Some forum content will be hidden from you if you remain logged out. If you want to view all content, please click the 'Log in' button above and enter your BMW MOA username and password.

    If you are not an MOA member, why not take the time to join the club, so you can enjoy posting on the forum, the BMW Owners News magazine, and all of the discounts and benefits the BMW MOA offers?

  • Beginning April 1st, and running through April 30th, there is a new 2024 BMW MOA Election discussion area within The Club section of the forum. Within this forum area is also a sticky post that provides the ground rules for participating in the Election forum area. Also, the candidates statements are provided. Please read before joining the conversation, because the rules are very specific to maintain civility.

    The Election forum is here: Election Forum

After valve adj engine wont turn over

andrewdell19

New member
Got a /5 about 2 months ago and it was running a little rough, mainly it would stall out when stopping if I wasnt rolling on the throttle a little. SO I decided to perform a valve and timing adj at the suggestion of my mechanic.

1. I unplugged the neg lead from the battery.
2. Then I took off the valve covers
3. Torqed the 6 nuts to 29 ft/lb- I think that it was it said in the Clymer manual- whatever that said...
4. Ready to do valve adj so I took off engine cover.
5. Insterted 6mm allen wrench to rotate the engine, found the OT in the window or TDC.
6. Inserted feeler gage and adjusted exh to 0.008" and the intake to 0.004". (There are also two other sources that said to adj to the intake to .006, and the other said that both intake and exh are supposed to be .004"
7. Did adj on the other side and reversed to put everything back together.

Started the bike and it started coughed and stalled; I tried it again and this is when I started to here more noise in the valve heads and the engine wouldnt turn over. The starter was going (I have /6 trans) but the engine wasnt turning over.

So I did the valve adj all over again making sure everything was in the correct places, rocker arms ok (very small vertical movement like suggested), but when I went to turn over the engine by hand with the allen wrench I noticed that it wasnt turning the engine over... the nut was loose :scratch so I tightened it and then I was able to turn the engine over to find OT. I thought that was weird.

Tried to start the bike again wouldnt turn over with the elec starter on the /6 tranny. In case it is the battery I will place it on a trickle charger once I get done posting.

SO I am looking at the bike not turning over but the starter def doings it thing; and the one instance of the nut being loose when going to rotate the engine by hand. Does the problem lie within that loose nut?

Thanks for your help! Sorry if I went on in detail but I am frustrated and wanted to make sure I got everything down. :bottle
 
I read through your post a couple of times and I'm confused. When you found the "OT" mark on the flywheel, did you verify the cylinder you were adjusting was on the compression stroke? Only one side is on the compression stroke at a time, the other side will be 360 degrees off (or one revolution of the flywheel). What 6mm bolt were you turning on the front of the engine? When you say the starter was doing it's thing but the engine wasn't turning over, do you mean the starter wasn't engaging the flywheel? Try to give a better description of what you did and what's going on and I and others will chime in and help you get this sorted out. If you adjusted the valves on BOTH sides while only finding the "OT" once, you have one side so far out of adjustment all it's likely to do is spit and sputter. Not to worry, help is here. Start all over and describe exactly what you did.

Ride Safe
Rideoften
 
Last edited:
Oops

Posible valve open when you ajusted the wrong side?:banghead
 
Last edited:
Others have mentioned that you probably didn't set one side while on the compression stroke. I have a few other suggestions, mostly which counter the Clymers. Some suggest using the Clymers to light a fire so you can see what you're doing when you repair your bike!!

29 ft-lbs is probably a bit much for the cylinder studs. That's putting additional pressure on the threads in the engine case and there's a danger, over time, of pulling them out. Next time, I suggest going to only 25 or so.

Turning the engine using the allen wrench in the alternator bolt is probably OK if you remove the spark plugs. Turning against the compression with this small bolt will eventually lead to rounding out the allen bolt. I've been putting the tranny in 4th or 5th gear and then turn the rear wheel while watching the valve action on the left cylinder. When I see the intake valve open and then close, I know that cylinder is on the compression stroke. I then reposition myself on the left side of the bike and then bump the rear wheel with my hand, watching for the F mark, the S mark, and finally sneak up on the OT mark. Set the valves. Rotate the engine 360 degrees or so that OT mark reappears the next time. Set the valves on the right side. Rotate the engine two more 360 degree rotations and check your work.

HTH...
 
I will also add to the suggestion that one side was adjusted while not on the compression stroke... unless you left that part out of what you did. You should get the bike to "OT", find the side with the "loose" (you can spin them by hand) pushrods, adjust the valves, then rotate the engine to "OT" again and adjust the other side - verify the pushrods are loose in case you went too far.

As for the bolt you're using to crank the engine over, I've had one come loose, as well. I was adjusting valves for a friend and it came loose. Really scared the heck out of me. It's not a huge deal as long as you tighten in back up. I know there is a risk of rounding it out if you're not careful, but I never had much luck rotating the engine with the rear wheel; I always went past "OT". Possibly a combination of the two would be good; rotate with the rear wheel until you're close to "OT", then zero in with the alternator bolt.
 
Did you remove the spark plugs? Well, you need to. I found that putting the bike in 5th gear in my case is much easier than messing around with the front cover. When you get up this morning and after you had your morning cup of coffee, I would go do it again, this time with rear wheel. I also do my valves a tight 9 exhaust and a tight 7 intake. Check your plugs to see what they look like to see what your carbs are doing... the head nuts should be tightened to 11lbs, 18lbs, and 25lbs; but when you loosen them, not more than 1/4 rotation, otherwise you break the seal...hope that all makes sense...:dunno Good luck. :dance
 
...but I never had much luck rotating the engine with the rear wheel; I always went past "OT".

Yes, that can happen. I straddle the rear wheel and pull the tire through while watching the valves. Once the intake valve closes, I then sit down by the timing hole and use my hand to "pop" the wheel around, nudging the engine rotation a little bit at a time. When I begin to see the F mark, my "pops" get softer, and softer still when I see the S mark. I find it quite easy to nail the OT mark using this method.
 
careful

Boxerkuh Is right, you may have a bad neadle & seat posible fuel loaded up and caused hydrstatic lock. If so cafully empty the cyl with no ignition sources. I have had this done to me and it ain't pritty when the starter is pushed. whooosh and fuel everywhere..:banghead :scratch:sick :gerg :bikes :ca :ca
 
Did you remove the spark plugs? Well, you need to. I found that putting the bike in 5th gear in my case is much easier than messing around with the front cover. When you get up this morning and after you had your morning cup of coffee, I would go do it again, this time with rear wheel. I also do my valves a tight 9 exhaust and a tight 7 intake. Check your plugs to see what they look like to see what your carbs are doing... the head nuts should be tightened to 11lbs, 18lbs, and 25lbs; but when you loosen them, not more than 1/4 rotation, otherwise you break the seal...hope that all makes sense...:dunno Good luck. :dance


Hey Guys... so I slept on it.

Yes I did do both sides by finding the OT mark twice... I knew which side to do because I could turn the pushrods. I also did take out the spark plugs- I hear it makes it a heck of a lot easier to turn the engine that way!! :thumb

So the 6 head nuts should each be tightened to 11 lbs then 18 lbs then 25 lbs after losening the one nut at a time 1/4 turn?

What am I to check the carbs for? They were fine (as far as I could tell) before doing the valve adj- but what can I check on them? (After doing the valve adj I was going to tighten each carb until it lightly sets and then gradually ease it out until the engine sounds right and then do it for the other carb- but I am not there yet)

If the flywheel is not engaging- can I check that by leaving the front engine cover off while hitting the starter? Is that safe? I know I have to disconnect battery before that first.

Spark plugs are a bit blackened (meaning oil is fouling them :banghead ) at the very tips but gaps still ok... I should replace those I guess for sure.

The rocker arms- they are supposed to have slight veritcal play right?

When at TDC- how are the pushrods centered in the hole? My other source says that the pushrods should be slightly above center in the hole. (http://w6rec.com/duane/bmw/valve/index.htm) There are some pics of the person doing the valve adj.
When you have the spacing between the valve and arm- are you supposed to push the pushrod in to ensure it is in place and there will be no movement in and out of the pushrod when that side is at TDC. Refer to 12, 13 and 14 of the link.

I appreciate all the help but I am at a loss right now and in the mercy of your hands and wisedom! Once this gets running I will dedicate the first ride to the beemerheads who helped me out!!!:bow
 
How much did you have to back the adjusters out to get them to clearance spec? I suspect you adjusted the wrong sides at the wrong time.

Whether you can turn the pushrods isn't the test, whether there's any slop in the valvetrain is. To test for the right side to adjust, you should be able to move the rocker arm back and forth a slight amount. The other side will be completely tight and you won't have any slop in it.

Now, you've got a bit of a problem in that you'll need to figure out which side is which. I would rotate the engine until one side is tight and adjust that side, then go to the other and do that one.

Your carbs aren't your problem, your ignition system isn't your problem. To quote one of Eilenberger's Laws - go to where you last touched it. That's where your problem is.
 
When I adjust valves, I remove only one valve cover at a time - that way I won't forget which cylinder I'm doing if the job is interrupted. I then turn over the engine using the rear wheel until I see the intake valve coming up - this absolutely means I'm approaching TDC for that cylinder. Using small bumps of the rear wheel it's very easy to get OT without overshooting. If I overshoot, I go back enough to compensate for slack in a worn timing chain, and repeat the small bumps to TDC. You don't have to remove the spark plugs if you're patient and wait for the compression to dissipate between each bump of the rear wheel. A hint to prevent nuts and washers from falling into the drip pan: remove the 10mm nuts and wavy washers first, then put the drip pan under the cylinder and remove the center nut. It should stay in the socket when you remove it. Remove the rocker cover, holding a finger over the end of the center stud to prevent the washer from falling into the drip pan.
 
How much did you have to back the adjusters out to get them to clearance spec? I suspect you adjusted the wrong sides at the wrong time.

Whether you can turn the pushrods isn't the test, whether there's any slop in the valvetrain is. To test for the right side to adjust, you should be able to move the rocker arm back and forth a slight amount. The other side will be completely tight and you won't have any slop in it.

Now, you've got a bit of a problem in that you'll need to figure out which side is which. I would rotate the engine until one side is tight and adjust that side, then go to the other and do that one.

Your carbs aren't your problem, your ignition system isn't your problem. To quote one of Eilenberger's Laws - go to where you last touched it. That's where your problem is.

Thanks KB! I didnt want to touch the carbs frankly because they were working before I did the adj- so the problem must be in the adj.

The way that I did the valve adj was I located the OT at TDC- then I rocked the crankshaft back and forth via the 6mm allen wrench. I noticed that on one side the rocker arms were moving slightly when I rocked teh crankshaft- the side that the rocker arms dont move is the side that I did first. Then rotated the engine found the other OT and rocked it back and forth to make sure the rocker arms were satationary and that is the side that I wanted to do next.

Now my mechanic said that the rocker arms should have some vertical play as does the clymer manual but this other source says there should be NO vertical play not even the slightest bit.

Refer to paragraph 9 for discussion on rocker arms... Should there be any vertical play? 2 sources say yes one says no
 
Now my mechanic said that the rocker arms should have some vertical play as does the clymer manual but this other source says there should be NO vertical play not even the slightest bit.

Refer to paragraph 9 for discussion on rocker arms... Should there be any vertical play? 2 sources say yes one says no

There is very little freeplay...you should see the oil film moving back and forth as you attempt to move the rocker up and down. Some people try to measure it but you just want to see the oil film moving in and out. If I had to guess, I'd say it was 0.002" or maybe even less...

As R60US and I said, you really don't need to rock the engine back and forth and worry if the pushrods spin or the rockers move, etc... As you turn the engine and the intake valve first opens and then closes, you're approaching TDC on the compression stroke for that cylinder. Then just slowly continue rotation until you find the OT mark. You'll be where you need to be. If you're not sure, try removing both spark plugs and put your thumb over the hole. When you feel backpressue on your thumb, you're on the compression stroke. Continue rotation until you see the OT mark.
 
I still think you made a mistake on at least one side. If you want to send me a PM with your phone number, I'll try and help you work through this. The fouled plugs aren't helping either, but if it ran before your adjustments it should be running now unless you made a mistake. You're getting the advice you need here, but a real conversation may get you back on track.

Ride Safe
Rideoften
 
FROM YOUR INITIAL POST:
Started the bike and it started coughed and stalled; I tried it again and this is when I started to here more noise in the valve heads and the engine wouldnt turn over. The starter was going (I have /6 trans) but the engine wasnt turning over.

Tried to start the bike again wouldnt turn over with the elec starter on the /6 tranny. In case it is the battery I will place it on a trickle charger once I get done posting.

Can you explain this a little more? "Wouldn't turn over" to me means that the motor is not cranking over (rotating with the starter) at all. If this is what you mean then we are trying to fix the wrong problem. If, on the other hand, you mean that the motor is turning over but will not start then we are (maybe) on the right track. Have you checked for spark?

John
 
How much did you have to back the adjusters out to get them to clearance spec? I suspect you adjusted the wrong sides at the wrong time.

Whether you can turn the pushrods isn't the test, whether there's any slop in the valvetrain is. To test for the right side to adjust, you should be able to move the rocker arm back and forth a slight amount. The other side will be completely tight and you won't have any slop in it.

Now, you've got a bit of a problem in that you'll need to figure out which side is which.
I would rotate the engine until one side is tight and adjust that side, then go to the other and do that one.

Your carbs aren't your problem, your ignition system isn't your problem. To quote one of Eilenberger's Laws - go to where you last touched it. That's where your problem is.

as stated earlier the trick is to watch the intake valve (the one toward the rear of the bike) as below in bold, when you see that one has just closed AND there is some play in rocker arms, you're on the compression stroke.

When I see the intake valve open and then close, I know that cylinder is on the compression stroke.

RM
 
...when you see that one has just closed AND there is some play in rocker arms, you're on the compression stroke.

You shouldn't assume there will be some play in the rocker arms. If the valves had closed up, then there wouldn't be any play. Unlikely that both would close up at the same time. But it could be from a previous misadjustment that there's no play...

But as you said, watch the action of the intake valve and use that as your cue.
 
You shouldn't assume there will be some play in the rocker arms. If the valves had closed up, then there wouldn't be any play. Unlikely that both would close up at the same time. But it could be from a previous misadjustment that there's no play...

But as you said, watch the action of the intake valve and use that as your cue.

yeah it is possible that they are so tight that there is no play when it cold but I would think the bike wouldn't run too well prior to the work esp. once it get hot and things start to expand, since it probably would not be letting the valves seat all the way, though it could be tight to the feel and still be closing completely but....

If one side was not done wrong then there may be something else going on unrealated to the valve job, I can happen as unlikely as it might seem. a bad adjustment of the valves would have to way way off to cause it not to run at all.

Has the location of the noise been determined?

RM

RM
 
Hey Guys!

Thanks for all the good reading! Sorry it took me so long to reply but work sent me out of town on a days notice.

So when I got home last night I put the battery on a trickle charger; I could immediately see the battery needed to be charged. It ended up taking 5 hours to bring the batter back to full charge.

I hit the starter and the bike started right up and it seemed to idle better than before. :thumb So I took it out for a ride and the first stop I came to I stalled out. But the bike started right up when I applied the choke again and I continued to ride around the block a few times.

But I noticed once as I came to a stop the RPMs stayed at about 2500 for a few seconds and then came back down.

Is a carb adjustment needed? or should I go back to the valves? I will have the whole day tomorrow to tinker and am looking forward to it!!

Thanks for the suggestions!
 
Back
Top