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Discussion in 'GS Boxers' started by jackhammer50, Nov 20, 2012.
No need to drain the oil, but by the fact you asked it, I assume you have never done your valves ?
No, I have done my valves twice now, but I always make a big service day out of it, engine oil, tranny, FD, throttle body sync, etc. etc. if I time it right new tires....
I really like the feeling of taking off with all fresh & new everything...
So I had my friend (with lots more mechanical knowledge than I) help me set the valves on my 08 GS for the 24K service. Bike had been running fine.
All valves were about halfway where they should have been, .075mm and .15mm more or less for intake and exhaust.
All other service was done at Lonestar BMW in Austin, this is my first time taking over.
Do dealers set them tight to keep the noise level down?
Does the spec I state above (.075mm/.15mm) so tight that damage might have occurred?
Notwithstanding the single value .15mm and .30mm spec, I assume there is actually a range. What is that range?
SOME deallers use a go-no go-guage. So sometimes they will be a tiny bit tight. I know of no dealer that would intentionally set them tight. Tight is bad. There really is no "range" like on the Camhead. They are either right, or they are not.
Jim, your continued assistance to the inmates is invaluable and cannot be overemphasized. Thank you.
It seems to me that the engine does not magically stop if the valves are a bit more tight or loose than spec so I was curious about the acceptable range even if BMW does not publish a range.
Also, what's with the use of one feeler gauge for both valves? I'm having a hard time wrapping my mind around what that gets you vs. doing one valve at a time.
1- No. don't drain your engine oil to adjust valve lash but do put a small container under the cover to catch the 2-3 teaspoons of oil that will come out of the loosened OHV cover.
2- Correct valve lash means two things. Each valve in the pair should be as close to it's mate as you can get it. This seems to improve engine smoothness. So, adjust the intake valves on one side of the motor so that they are equal. Same for the exhaust. As for actual valve lash, not as important as equal. I used to visit with an experienced BMW tech where I bought my GS. He said he had some customers who preferred the valve lash to be a bit tight for added high RPM performance. If requested, he adjusted oilheads to one half the BMW lash spec for both intake and exhaust without consequences and this was in Houston TX summer heat. So, unless your exhaust valves are have no clearance or you are experiencing intake backfiring, I would not be concerned about discovering tight valve lash.
3- Me? I run my valves loose deliberately in order to improve starting and provide smooth engine operation at the lower-mid RPM range. I rarely explore red line on my '01 boxer. There just isn't any reason to go there unless you like high speed combustion and a slight loss of power. Last time I was at red line, I had forgotten to shift from 4th to 5th when I was racing a cage. I actually saw just over 7000RPM on the tacho...never done that before. I was not impressed as I felt the power fall off. :eek1
4- All valve lash adjustments should be made with the engine stone cold.
Using a single feeler between the two valves allows you to feel if one is tighter than the other. If you pull from the middle the tighter valve will drag more and you will know they are not the same.
Read this, it might help: http://www.jimvonbaden.com/R1200_24K.html
Is there a particular source for such a gauge that will reach both sides?
I bought the beemerboneyard gauges and they don't reach although I was thinking that they might if I remove the plastic off the handle end.
I got mine from Autozone. I use the exhaust one full size, and the intake I cut half an inch off. This is the set that you can remove individual pieces and cost about $7.
Thanks. Will run down to Autozone and readjust the valves, as there seems to be consensus as to the approach and it makes sense to me now.
Any body else see a problem with this?
I've got the worry beads out.
I'm actually just a glorified gopher for my friend who is "helping" i.e. doing this and what he told me is what I posted.
"we" could not get the .15mm and .30mm gauges in and by fiddling around with various gauges my friend determined that they were all at about half where they should have been.
I try not to get into it, but running that tight risks burning a valve because the valve doesn't spend enough time seated.
On a positive note at least there was some clearance. Adjust them properly and ride it, throw the worry beads away.
Exactly, nothing gained from worrying.
However, I am going to go through them again as suggested by the Oilhead Valve Adjustment for Dummies (OVAD) to get them fine-tuned.
The lateral play was on the edge of spec according to my friend so I think I'm going to go ahead and adjust that too while I'm at it.
Another thing I learned from the OVAD was the tightening of the nut on the valve adjustment. It's clear to me (:huh) that I over did it but hopefully did not cause permanent damage. 8 Nm is not a lot of torque. The nut is clearly easy to replace, how about that 3mm allen bolt? I could not make heads or tails of the Max BMW fiche.
Anybody willing to help me id the PN for that allen bolt? The bike is an 08 non adventure GS.
Thanks to everybody that has been helping with this. At some point, once I get my knowledge built up a bit, I can hopefully pay it forward by helping someone else.