Interesting, My BMW official workshop manual seems to indicate measuring end float at the bottom....
Ah - but did you receive all the updates?
Adjusting rocker end float, and valve clearances
- Thread starter Steptoe
- Start date
Ah - but did you receive all the updates?
Uh Oh. That's thrown a spanner in the worksInteresting, My BMW official workshop manual seems to indicate measuring end float at the bottom....
Sent from my SM-G975F using Tapatalk
The photos are back! Good stuff.
Ok then 
There will always be a different measurement reading top and bottom but also when turning the feeler gauge through 90 degrees, the two rocker shaft supports are never parallel to each other so the only reading which gives true end float will be with a dial gauge on the rocker
There will always be a different measurement reading top and bottom but also when turning the feeler gauge through 90 degrees, the two rocker shaft supports are never parallel to each other so the only reading which gives true end float will be with a dial gauge on the rocker
I think that the problem here was the written word, does not portray the true intention of what you mean.
I can now see that you do have the experience in working on the machines, and that is quite evident from some of your comments, but it may just be me, but when I have dealings with a given service provider, that forms my opinion.
I wish you well in the future, and should I ever make it back up to port sunlight I'll buy you a pint.
Neil
Ill take you up on that
It is REALLY easy to make assumptions from the written word. Especially on forums. So I have taken no insult whatsoever as I'm guilty of it more than most. Take care buddy
Interesting, My BMW official workshop manual seems to indicate measuring end float at the bottom....
See. That's exactly what I'm talking about with BMW changing their methodology. That's obviously from a very old manual. I've probably got that DVD knocking around somewhere. But if you look at the very latest ones, it shows it from the top.
I was working on an old 1100RT yesterday. I could easily slide a 0.15 thickness gauge into the top. But I couldn't even get a 0.05 gauge into the bottom. However, there is float in there. I could 'Just' make it move. Which I personally think is good.
If you think about it, the top is static. That bearing cap cannot move. The lower one however can. So it's possible for it to be slightly quiff. Which could throw out your readings. Maybe that's why they changed the methodology. Or maybe the guys who write the manuals don't know either and just use whatever stock images they can find on the day. Who knows !!! I've met a few of the technical guys over the years. They aren't the grey haired Wizards with Vernier callipers in their top pockets that we all like to imagine. Some are just white collar IT geeks with no mechanical experience at all.
And if you took your bike to a main dealer, they won't even measure it at all. Most won't even know what end-float is.
To summarise: You need SOME end float. If you can get a 0.05 in the top or the bottom, then you're going to be okay. You can safely run the engine with up to 0.40. Which is actually quite a lot and you can really wobble them up and down when they measure like that.
It's REALLY hard to get the gap to close to 0.05 on the top anyway. After you've knocked it smaller with your rubber mallet and hold it in position, once you torque it all down again, the gap is usually 0.10-0.15.
Does anyone else think that we're over thinking this ????
Now don't you start becoming all sensible and using common sense and all that sort of thing
I always did the float at the top as it made sense as the leverage wants to push the rocker arm upwards and I guess at the end of the day you get a feel for it if for example there's a lot of play and warrants further checking and/or adjustment
keep yourself sane and keep fettling those motorbikes
sJust done this joband found this thread useful. First time I used the 4 job specific feeler gauges bought for about £12 on eBay. With all 4 loosely nipped in place very interesting to see how the adjustment of one valve immediately affects the clearance of not only it’s partner but also the valves on the other side. If you’re in any doubt 4 feelers seems the way to go.
Agree with post above that it is really difficult to set the end float to the min clearance. I tried this last time an on measuring again found the top gap larger from inlet to exhaust and also around the measurement half circle as if the cross piece was on a slant. Finally got them equal at about .07 but when tightening up it increased to .10. Pretty sure at this level of end float the allowed lateral movement should not affect the consistency of valve opening clearance and affect performance.
Agree with post above that it is really difficult to set the end float to the min clearance. I tried this last time an on measuring again found the top gap larger from inlet to exhaust and also around the measurement half circle as if the cross piece was on a slant. Finally got them equal at about .07 but when tightening up it increased to .10. Pretty sure at this level of end float the allowed lateral movement should not affect the consistency of valve opening clearance and affect performance.
cheers Steptoe , knowledge is always relevant .
i guess i owe you another box of chocs.
i guess i owe you another box of chocs.
Johny w
Registered user
That's excellent, thankyouChecking valve clearances and rocker end float ;
When removing the valve cover, the inner gasket has a habit of staying in the head. Gently remove it and fit it to the cover, if left in place you’ll most likely “pinch” it when replacing the cover, and find you’ve an oil leak.
If you remove the cover, and it looks like this - the inner gasket is still stuck in the head
There it is inside, gently pry it out , and fit it to the cover
How you want it to look
All the following work must be done with the engine COLD
The engine must be at TDC on the side your checking, before any clearances can be measured. I always start on the L/H side, then do the right. It requires less turning over of the engine.
Set the engine to TDC (top dead center), put it in gear, remove both spark plugs, and turn the engine over by rotating the rear wheel by hand. On the cylinder your looking at, You want the inlet valve to be closing as the piston comes up to TDC, if you don’t know what I’m talking about, you shouldn’t be attempting this job ; ) insert a small screwdriver or straw into the spark plug hole, and as yourotate the wheel the screwdriver/straw will be pushed out of the spark plug hole, when it reaches the max coming out point, stop. That’s the TDC.
Before you check the valve clearances, you also want to make sure the rocker endfloat is within tolerance - The clearance allowed is between = min 0.05 & max 0.40 . ( the same for inlet & exhaust)
Where to check the endfloat
It’s better to keep it at the minimum gap, it helps surging problems , and runs much better.
Here’s where the benefit of doing it yourself comes in. Most workshops will leave it if it’s inside the spec, less unnecessary work for them . But you’ll never have the sweet running bike that you could have.
To adjust the endfloat, you’ll need a T45 socket, and a 15mm hex socket. And a torque wrench to do it all back up.
Here’s the 3 torq bolts .
And the one 15mm hex bolt.
Undo them all, then just nip them up finger tight.
You then tap the lower rocker support bar until the gap is correct . This can be a pain in the arse, and seem a bitof a bodge, but it’s how it’s done. Just take your time.
The support bar
Now torque up the bolts - the torq bolts are 9nm .
The hex bolt is a cylinder head bolt, so needs to be tightened to 20nm, and then turned another 180 degrees.
When you’ve done that to your satisfaction, you now measure the valve clearances.
Inlet 0.15
Exhaust 0.30
Measuring the valve clearances
To adjust the gaps, you’l need a 10mm spanner ,and a 3mm allen key. The 10mm nut is a lock nut, you adjust the gapwith the allen key.
Adjusting the gaps
When your happy with all that, you then repeat it on the other side.
Remembering to get the engine at TDC on that side before measuring any clearances.
The end result of both the valve clearences, and more importantly the rocker end float ( plus the throttle sync afterwards) will give you a bike smoother and quieter, and more responsive.
Taken me longer to type this than to do the whole job from start to finish.
Just one thing on this subject.
I tend to do the valve clearances as part of a service, and part of that list of things is checking the Alternator belt tension. If you take off the alt-belt cover you can then turn the engine using a 16mm spanner or socket instead of turning the rear wheel with the bike in gear. It's a bit easier then to watch the piston movement, or your indicator device. once you're done with the valves, and the alt-belt is fine, the cover is easy to get back on (use coppaslip).
Remember - ONLY turn the 16mm nut clockwise (usual tightening direction). (you don't want to undo that nut).
I seem to remember reading something a few years back where certain owners (probably americans) used to cut a hole in the alternator belt cover and install a cap, so they could access that nut on the end of the crankshaft without taking off the whole cover, but that seems a little bit like overkill to me......
I tend to do the valve clearances as part of a service, and part of that list of things is checking the Alternator belt tension. If you take off the alt-belt cover you can then turn the engine using a 16mm spanner or socket instead of turning the rear wheel with the bike in gear. It's a bit easier then to watch the piston movement, or your indicator device.
once you're done with the valves, and the alt-belt is fine, the cover is easy to get back on (use coppaslip).Remember - ONLY turn the 16mm nut clockwise (usual tightening direction). (you don't want to undo that nut).
I seem to remember reading something a few years back where certain owners (probably americans) used to cut a hole in the alternator belt cover and install a cap, so they could access that nut on the end of the crankshaft without taking off the whole cover, but that seems a little bit like overkill to me......
Johny w
Registered user
Thanks, it makes sense, and i can check the belt at the same time but I wouldnt knowhow to test the tension!! can you do a twist test? ..... the hole in the guard seems a canny idea to me.Just one thing on this subject.
I tend to do the valve clearances as part of a service, and part of that list of things is checking the Alternator belt tension. If you take off the alt-belt cover you can then turn the engine using a 16mm spanner or socket instead of turning the rear wheel with the bike in gear. It's a bit easier then to watch the piston movement, or your indicator device.
Remember - ONLY turn the 16mm nut clockwise (usual tightening direction). (you don't want to undo that nut).
I seem to remember reading something a few years back where certain owners (probably americans) used to cut a hole in the alternator belt cover and install a cap, so they could access that nut on the end of the crankshaft without taking off the whole cover, but that seems a little bit like overkill to me......
Two types of belts depending on the year of bike. One needs adjusting, one is elasticated and doesn’t,
Whats the years for those belts Steptoe; and are they interchangeable; mines a 95 R 1100.
Later 1150 models with servo brakes use the elasticated belt. If they need replacing I fit them with the non elastic belt. Especially the adv models with the link fuel pipe. The elasticated belt alternator is very low and can sometime stop the fuel line from being pulled under when removing the adv tank. Using the normal belt means the alternator sits highly
Cheers Steptoe;
Does the bridging fuel line pass directly under the alternator on the GSA? (I've never worked on one) Interesting, useful to know.
The pipe joins both lower lobes so you can use the fuel ftom the lower left lobe.
The Q/D can get stuck if the alternator is too low. Especially if someone has fitted a non standard all metal Q/D
Yeah - I understand what the pipe is for: I just didn't think it would be passing directly beneath the alternator. I would have imagined the pipe would be a bit further to the rear of the bike (ie, behind the alternator rather than in line with it). Every day is a learning day.
Yeah - I understand what the pipe is for: I just didn't think it would be passing directly beneath the alternator. I would have imagined the pipe would be a bit further to the rear of the bike (ie, behind the alternator rather than in line with it). Every day is a learning day.
It’s why some people have a Q/D on both sides and leave the link pipe in place when removing the tank.
