The New And Improved Unofficial R65 Forum V2
Technical Discussion => BMW Technical Q&A, Primarily R65 => Topic started by: guyom on June 19, 2017, 01:48:28 PM
-
Hi guys, i read a bit on valve clearance.. and to be honest i am good for electricity or external stuffs.. but i do not good in term of engine... so just standard question (got a 1981 R65) :
1- except the mixture check, oil and oil filter... carb adjustment, do you do some maintenance in the cylinder...? valve ?
2- it sounds that my bike, on the left side, "clic clic clic" more in term of sound that the right part. What can it be ?
Some screws to check ??
Thanks for time
Guillaume
-
also do you all have a torque wrench in your tool box as an essential tool to have ? i checked a tutorial on valve clearance and never do anything on my bike since 3 years... well roughly 3000 kms...
-
You need to perform a valve clearance check on a cool , warm to the touch engine, an engine that has not just been run .
It would be good idea to check the torque of the cylinder head nuts, before you start the clearance check seeing as you are not the original owner and who knows what was done to the bike before you got it .
So you are going to need a torque wrench .
Here's a youtube video on how to adjust valves on an R100 .
Warning, the language is ' colorful ' at times !!!!!!!!!!!!! ;D
https://www.youtube.com/watch?v=VExx_2kIc9c
I have an '81 R65, original owner, the '81 model year airheads were the worst for valve recession .
I had the heads rebuilt at 45,000 miles, around 73,000 km .
The exhaust valves were close to failing, they were worn razor thin at the contact area with the valve seat .
-
Hello !
As you are new to engine tune-up, here is the procedure I follow at every oil change which is 5000 km because I mostly do commuting in a mildly hot climate with a lot of in town traffic.
First of all start with a cold engine which has not been run for at least 8 hours and below 30 °C (which could be difficult to achieve in some place)...
Check and set valve clearance (and note the value found when checking in order to see if there are valve recession).
Check ignition timing (and dwell if using points) and eventually change the plugs.
Go for a ride to warm the engine.
When back in the shop balance the carbs and adjust idle mixture.
And do the oil change with the oil warm.
The main thing to remember is that you MUST adjust the carburetors on a sound engine (valves properly set, proper ignition, ... ) otherwise you will be doing crap work...
For me it is a routine and I could do this eyes closed, almost. ;-)
-
Georges method is a good one and will get the job done. Having a routine makes for a slick operation.
My service routine has one difference. I now do the valve clearance on a warm engine. For safety not hot enough to cause burns but only cooled for 30 mins from the engine having been hot to drain the oil. There is no need to do valve clearances on a stone cold engine as the gaps will not change to any degree that you can measure. If any one doubts that try setting them warm and check again when the engine is stone cold.
I'm only a relatively recent convert to this method and spent 40 years religiously doing them stone cold. Not That I ever used dealer servicing but do you think they ever did them stone cold.
-
Barry - are you saying that there's some benefit to doing the adjustment slightly warm? Or just that it's not necessary to wait for a complete cool down?
-
hey guys ! thanks a lot... so as mentioned, i have a 1981 R65.. so the worse for clearance ;-) and not the origin owner.. so yea clear.. i will buy a torque wrench and to a check up... ! Thanks for time and advices !!!
Guillaume
-
just a short question on torque wrench : i easily found 2 models :
1- torque range = 50-250 foot-pounds (70-340 Nm)
2- torque range = 50-250 inch-pounds (6-30 Nm)
but if i am right, torque of the cylinder head nuts are 25Foot-pounds x 1.356 = 34Nm
I am not in the range of both... so considering the price of a torque wrench... which one you choose to buy ?
Thanks for time.
-
Whoever wrote "50-250 foot-pounds (70-340 Nm)" wants you to pull head stud threads!
I torque to 20 lb/ft which I think is about 5 lb/ft shy of max. I always err on the light side as I have no desire to do a block thread repair! :o
-
Neither of the two torque wrenches are really suitable for airhead use, you want one in between the two. A typical 3/8" drive wrench would be something like 10 - 80 ftlbs and that would cover most needs. Anything with a bigger range wouldn't be accurate enough for the head nuts.
-
I have a nice 3/8" drive "antique" SK beam type which is perfect for these light jobs...
-
Ideally you want to use most torque wrenches somewhere around in the middle of its range, say, 25% - 80% for best accuracy. So, keep a lookout for something like an 80 foot pound or no more than 100 foot pound wrench for most uses
-
Hello !
I'll compound all what was said above :
You need two wrenches. One in the 5~40 Nm range for the heads and stuff like that and another one in the 50 ~ 200 Nm range, the high figure being used for the output flange nut on the tranny.
Buy good quality torque wrenches because the cost of repairing a failed stud due to incorrect torquing is wayyyy more that the cost of a good quality tool...
-
Hi guys, thanks for advises. Just a last question : consensus for valve clearance for a R65:
0.004" inlet and 0.008" exhaust so 0,1mm and 0,2mm
Correct for all you?
-
It's really not that important give or take one or two thou and BMW even changed the guidance 2 or 3 times but .004" and .008" is what they finished up recommending. It's what most people use.
What is important is consistency of technique so that you get both cylinders as close to the same as possible.
-
Hi Barry thanks. You mean that the values (example 0,004" and 0,008") should be the same for the left and right cylinder. Correct ? Thanks for time !
-
Yes, make the left and right as close as your reasonably can so that when you go to synch the carbs afterwards, you'll *know* that the (2) cylinders are sucking in air/fuel at the same rate, so any imbalance will be in the carb adjustments.
0.004" intake and 0.008" exhaust work fine - I think I run mine at about .005"-.006" intake and 0.008 exhaust. You don't really want to go more than this or the valves do get a bit extra "clackety-clackety". Though, as we say in Airhead land - "Happy valves are tappy valves!". When you cannot hear any valvetrain noise, that is when you have to start to worry and get in there
-
Valves are like kids. When there not making any noise, trouble is not far... But too noisy is not good either. Just like kids ;-)
-
Hi Barry thanks. You mean that the values (example 0,004" and 0,008") should be the same for the left and right cylinder. Correct ? Thanks for time
Yes, use the same clearances both sides but what I was trying to stress was the the setting isn't that critical so for example if you set the inlets at .005" it really doesn't matter as long as both sides are at .005" and more over you use a consistent technique to make sure both sides are as close to exactly the same as you can get them.
-
Hey Thanks all for reply ! (like the comparaison between kids and valves ;-) got three boys so understand very well this concept ;-))
again a question : when i remove the covers, the right one, low amont of oil inside, but the left one... at least 10-20cc... it is normal or there is something unscrew... i checked the video on valve clearance setup and at some point the guy uses clamps to screw "something do not know the name" and the result was to reduce some movement of the small arms (valve rocker i think)... i do not see any screws at the bottom and top of my R65... how i can check that. i looks like on arm moves up and down a bit more where there is more oil on the cover...
no sure i am super clear...
Thanks for time
-
He is trying to tighten up the side play in the rocker arms by using a "C" clamp to squeeze the shaft supports together
You want it to be zero play but not tight
It has nothing to do with valve lash but can cause noise
The later rocker assembly's came shimmed from the factory
I just bought some standard stainless steel shims with the proper 16mm ID .05 mm thick and used them on mine to take up the end play of the rockers on the rocker shaft
BMW sells the complete update kit but it isn't necessary
-
HI Guys thanks for feedbacks..
So i checked the clearance and then adjusted the carb. A bit noisy on right side but i will check in 200-300 kms. Just for my information : why valves clearance and rocker adjustment impact on carburation ? if i will understand the order is : Valve clearance --> Carb synchro --> Carb mixture (that's what i did).
thanks
Guillaume
-
Barry - are you saying that there's some benefit to doing the adjustment slightly warm? Or just that it's not necessary to wait for a complete cool down?
Sorry I'm more than late responding to this.
There is no benefit other than the convenience of fitting it in to a service. It's just not necessary to wait.
HI Guys thanks for feedbacks..
why valves clearance and rocker adjustment impact on carburation ?
It's because when you change valve clearances you also make small changes to valve timing. For example if you reduce the clearances the valves are open a little longer and there is more overlap (inlet and exhaust open at the same time). This will require a slightly richer idle mixture than a wider clearance because you reduced the efficiency of the engine at low speeds.
Conversley if you set the idle mixture properly i.e. only as rich as it needs to be, then increase clearances by a couple of thou, it will raise the idle speed and require a slightly weaker mixture.
-
There are shims available from BMW, to put on the the rocker arm shaft between the arm and support blocks at each end .
http://www.realoem.com/bmw/enUS/showparts?id=0364-USA-09-1980-248-BMW-R65&diagId=11_1698
Item # 17, available in various thickness .
I've got about 77,000 miles, 125,000 km on the shims and they are just showing signs that they need replacement .