R1250GS Valve Clearance Check

[@CLLUK]

Update: 24/01/2024. Since resetting the Exhaust Valves, the starting is still not completely normal. Sometimes it starts okay, sometimes not. So, I decided to open up again and look at the Auto Decompressions Mechanisms which are positioned next to the Exhaust Valve (Front) on both cylinders. (I should of done this the first time!) The Auto Decompression Mechanism only operates on the Front Exhaust Valve. Comparing both sides, it was clear that the RHS was OK and the LHS defective. This just flops around and doesn't return to the 'Start' position (ie, with the rounded profile protruding slightly above the cam lobe surface. So, this is indeed Good News and makes sense why sometimes starting is OK and others not so. I now need to look into a change out. I will upload a video on what I found later today or tomorrow.

[@CoffeyPowell]

Well just reading the first 40 seconds of writing on the screen tells me I need to have a pro at the dealer check and replace shims on my 2019 RT

[@MrCruiser666]

Great instructions for the clearance check, thank You! But the adjustment needed : 1: Timing Chain Tensioner Assembly - BMW part # 83300444292; (tension for chain like in working mode) 2: Cam Alignment Jig - BMW part # 83302467268 (OK, you marked the gears, but the shaft alignment is also adjustable - right side 65 Nm ) I wonder how can you fix the decompressor! btw. I have the same starting issues. 2021-1250GS 27000km for a few months My bike has warranty, but I read everywhere dealers can't solve this problem.

[@CLLUK]

Thanks. Waiting for the replacement cam shaft and specialist tools. Will need to redo valve clearances checks of course and also cam alignment. I hope to start when everything is here ( ~ 2 weeks ) Will upload another video with all the information. Looks like you've been doing your own research too! 👍 I would love to know why it failed in the first place?

[@CLLUK]

Forgot to mention. The auto decompressor is integral to the exhaust cam shaft :( It comes as one part ( auto decompressor and cam shaft.) Minus the Gear Wheel and reluctor which I have to remove from the defective cam shaft and fit onto the new one. Yes, you're spot on 65Nm for the 16mm hex bots at the end and 8Nm for the Reluctor ( That's what BMW call it - the plastic composition component at the end and is part of the positional feedback system to the ECU. )

[@marcelodc8801]

Very good. It help me a lot. Thanks.

[@wacksalad3110]

How did it go then ? This is a big issue. I think it would be great to hear how you got on. Very much appreciated.

[@CLLUK]

Hi, yes, I think you're absolutely right. I was really sure that the Auto Decompression Mechanism was defective on the LHS. Now, after comparing in more detail with the RHS and others I don't think it is. I still need to complete a few further checks. What I see, though, is that the cam alignment looks out. So I shall be very soon carrying out a Cam Alignment. I've got the specialist tools for this apart from the "Cam Chain Alignment Tool" which after days of searching seems impossible to obtain. ( I did find a German retailer and ordered it, but the next day they informed me it was discontinued and refunded me :( But, good news is that I will hopefully have one on loan soon from the BMW Motor Club UK ( Southern Section ) So I will then do the Cam Alignment and put everything back together again and fingers crossed, test and ride. So, regardless what happens, I will upload a video on this bmw auto decompressor as it's different from what I am used to on other non bmw bikes. The 2nd video will be on the CAM Alignment procedure. I'm just hoping after all this, it resolved this starting issue. If it does, then it will be two things I've done. (1) Adjust valve clearances. (2) Adjust Cam Alignment. If it doesn't, then back to the drawing board.

[@yetiiti7631]

Thank you for the movie, the procedure was nicely and succinctly presented. I don't entirely understand the purpose of this tool "Cam Alignment Jig" - is it used to set the cams before checking valve clearances, or is it for setting during basket assembly? Or other purpose? Thanks in advance for clarifying.

[@CLLUK]

Thanks. The purpose of the Jig as I understand it is to lock the inlet and exhaust cams in their correct position at TDC whilst tightening up the end bolts to their correct torque. You raised a good point. I think it makes sense to do the cam alignment (that's if it need doing) prior to doing the valve checks/adjustment.

[@stevendettman]

Where can I find true metric feeler gauge set?

[@CLLUK]

I just searched on Amazon and Ebay. Seems to be available. I purchased mine so many years ago.

[@stevendettman]

@ it seems like set I see on Amazon, for example, are imperial with an equivalent metric measurement. I’m wondering about true metric feelers.

[@rumien1383]

I bought a jump starter after this problem occurred. I never travel without it.

[@CoffeyPowell]

I have found that if I have it in neutral and then still pull in on the clutch lever the starter does fine.

[@CoffeyPowell]

I'm thinking why were only the exhaust valves out of spec.? Duh. ..... The exhaust valves experience carbon buildup. I'm thinking every 1250 CC motor needs to have valve clearance checked whenever the engine starter motor is struggling to turn the engine over. I have 37,000 on my 2019 R1250Rt and was experiencing that problem at 15,000. I'm hopeing once I have it done the bike should be ok for another 50 -60 thousand miles. I know the book recommends checking every 12k but at $650 per check that is just not rational. Remember these dealers are there to make money. I want to support them so they will be there when I need them but that's highway robbery. Thanks for a great video.

[@CLLUK]

Thanks for watching and your support. Glad it was of help.

[@alexstan5358]

Decompressor stuck! Do BG hot oil flush and use only 5w40 Jaso Ma oil like Motorex/Motul/liqui moly ester full synth with oil filter that has non return regulating valve. ALWAYS RUN ALL VALVES AS LOOSE AS YOU CAN!!! If tolerances are at minimum , when hot cams are going to wipe oil film , causing cam lobes to wear out!!! These engines when valves are adjusted 0.25mm intake and 0.40mm exhaust they go for 300.000-400.000km easy

[@CLLUK]

@alexstan5358 Thanks for your comment, Alex. Interesting what you have stated regarding running with loose (larger rather than smaller tolerance.) Tolerances. Not heard this before.