tappet clearances at 12000 miles

Having Problems with your BMW R1200RT/R1250RT? or have some Maintenance and Service questions?
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audibob2
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tappet clearances at 12000 miles

Post by audibob2 »

I have just started the 12000 mile service on my 2015 R1200rt .

The right cylinder valve clearances have yet to be checked.

Both left cylinder intake clearances were in the mid range at 0.013mm, but the left front exhaust was 0.035mm and the rear exhaust was 0.030 mm

I am surprised at the exhaust clearances, is this normal for such a low mileage? Did not expect that.

The left cylinder cams are in perfect alignment. Hope the right are too..

The shim calculator on Jim von Badens web site looks very useful, it gives you the shims required to get them back to the mid point,

just input your gap and current shim size. Gives a list of BMW shim sizes and part numbers too.

I Will post the right cylinder clearances next week.

Bob
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sakm
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Re: tappet clearances at 12000 miles

Post by sakm »

Bob I think you have the decimal place in the wrong place ;)

I have just checked mine and all was within spec at 22k with no record of any been replaced in the past

I'm guessing you have all the cam alignment tools to check the timing too?
audibob2
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Re: tappet clearances at 12000 miles

Post by audibob2 »

spot the obvious mistake...doh..

The nearside cams were in line, although not using the factory tools. She always starts on the first press, so good enough. Will see what the

offside cams are like.

I can use the 1.98mm shim from my rear exhaust in the front , which will set it at 0.37mm. and the new 1.90 shim in the rear to set it to 0.38mm .

Both inlets are in the middle with 2.20mm shims in place.

gear timing via paint dabs, main sprocket cable tied, and tensioner slackened .

Fortunately it is only a fifteen minute drive the my local dealer . That R18 looks an absolute beast..

Bob
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sakm
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Re: tappet clearances at 12000 miles

Post by sakm »

@audibob2 you can't check the timing like that you have to have the correct tools

You have to tension the cam chains to a specific amount and then check the alignment with the jig and it can be a fraction out for it not to fit

If it is out it would probably only be a fraction anyway
audibob2
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Re: tappet clearances at 12000 miles

Post by audibob2 »

Hi sakm,

I am aware of the correct way, but as it was only a quick visual check, and my bike starts hot/cold instantly, then it will do until I have my local dealer

check them later in the year, it will be cheaper than buying the tools just to use once.

The rest of the service schedule I can do myself, as I have the gs911 scan tool .

Bob
audibob2
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Re: tappet clearances at 12000 miles

Post by audibob2 »

My offside clearances are all in spec, although there is one suspicious white dob of paint on the inlet cam gear, but nowhere else. Odd

My offside cams are aligned, although not using the proper tensioner tool....
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sakm
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Re: tappet clearances at 12000 miles

Post by sakm »

audibob2 wrote: Tue Mar 07, 2023 10:20 am Hi sakm,

I am aware of the correct way, but as it was only a quick visual check, and my bike starts hot/cold instantly, then it will do until I have my local dealer

check them later in the year, it will be cheaper than buying the tools just to use once.

The rest of the service schedule I can do myself, as I have the gs911 scan tool .

Bob
It will more than likely be fine until the 24k service or until it stops starting :lol:

I'm one of these that like things perfect and would check it every year and adjust if need be the first use of the tools will probably pay for itself and as such I bought them
audibob2
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Re: tappet clearances at 12000 miles

Post by audibob2 »

The need to use the BMW tensioner to set the cam timing is a bit odd to me. Cam chain tension has a big impact on keeping the cams in perfect

timing , but to use the special tool , which I presume sets the chain tension different to the normal tensioner, otherwise why use it, means that the

cam timing would alter slightly once the normal tensioner is reinstalled.

Why not set the timing via the normal tensioner , as long as it is good condition.

Perhaps the BMW tool is required to set the chain tension exactly as a new tensioner would, with a new chain, ie from a new engine, then if the

cam timing is out at a higher mileage, then it would point to a worn tensioner or chain. Does that make sense?

Bob
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Re: tappet clearances at 12000 miles

Post by sakm »

The tensioners are hydraulic which are pressurised by the oil pressure once the bike is running

Once the oil pressure has dropped as does the pressure from the tensioner so you need to tension it to the correct tension to get everything lined up correctly.

As the bike gains mileage the chains will start to wear and stretch hence the need to bring them in to time.

Mine was slightly out at 22k but not sure if it was done at the 12k service
audibob2
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Re: tappet clearances at 12000 miles

Post by audibob2 »

Thanks sakm, that now makes sense.

As this is my first modern boxer, I presumed the tensioner was sprung only. When my bike is around the 20k mark, I will buy the tools and check the

cam timing.

Thanks
Bob
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