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It has come to the time where the valve clearance on my 2005 1050 needs adjustment and I might have messed it up.
I set the TDC point on the crank with the arrows on the cams facing each other as per the manual.
Its not easy to see the arrows through the frame and cables but I thought it was set correctly.
Then when I lifted the cams out I noticed they also have triangles on the opposite side of the cam.
I now have this horrible feeling I might have set the arrows together thinking they were the arrows.
So my question is :
Is there any way I can check the crank is in the correct position before reassembly ?
I know the first piston is at TDC but not sure which stroke ?
I hope there is some way of putting my mind at rest.
Thanks, Phil.
 

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Usually... at TDC, piston 1 valves should both be closed / followers free to move, wheras the next TDC position will be between exhaust / intake so valves just open(ing), there shouldn't be any slack on the rockers (should be the case for all four stroke engines!)
 

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Thanks for that. It makes perfect sense. But not sure that helps me know which TDC the crank is on at the moment without the cams fitted ? Is there anyway of telling if its on TDC power stroke or exhaust stroke ? Sorry if I am asking something that is obvious.
 

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There is only one TDC for each piston if you have the cams out so it doesn't matter. All you need is to have # 1 piston at TDC. As for the triangles on the cam sprockets you aren't the first to have possibly confused them with the arrows. The timing marks are most definitely arrows like this → ← and the triangles are definitely like this ∆.
Picture attached of one of mine with the arrows in alignment.
timing_chain_and_timing_marks.jpg
 

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Out if interest, how many valves needed adjustment and what's your mileage? I've done 3 checks on mine and so far haven't had to adjust anything
 

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Out if interest, how many valves needed adjustment and what's your mileage? I've done 3 checks on mine and so far haven't had to adjust anything
Nearly all valves were on top limit and four were over. Mainly on piston 3. So I decided to do them all to centre limit and had to order 6 shims. She has done about 45,000 miles.
 

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Discussion Starter #7
There is only one TDC for each piston if you have the cams out so it doesn't matter. All you need is to have # 1 piston at TDC. As for the triangles on the cam sprockets you aren't the first to have possibly confused them with the arrows. The timing marks are most definitely arrows like this → ← and the triangles are definitely like this ∆.
Picture attached of one of mine with the arrows in alignment. View attachment 721367
Thanks Terry. That photo looks very nice without the frame and cables in the way. You say there is only 1 TDC on the crank without the cams fitted ? But surely the ignition is timed to fire on every other TDC ? I am worried that the ignition will be firing at TDC on the exhaust stroke or does it fire every stroke ?
 

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I'd assume the ignition and injection timing is based on the cam position.

I'd you think about it, when starting the engine, the ECU can't know which TDC the engine is at solely from the crank position so it has to also use the cam position sensor to determine what to do
 

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it's the depression measured by the MAP (manifold absolute pressure) in the throttle body that gives the stroke information.
BTW there is no cam position sensor on those engines.
 

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Thanks for that. It makes perfect sense. But not sure that helps me know which TDC the crank is on at the moment without the cams fitted ? Is there anyway of telling if its on TDC power stroke or exhaust stroke ? Sorry if I am asking something that is obvious.
Sorry I'm a donut, misread your initial post. As Terry says, only one TDC for a piston. Its the camshaft defines the stroke (as Macduff says). Think back to the old days when distributor was driven by worm gear off camshaft. Nowadays some engines use camshaft sensor, and here as fred says its via pressure differential (caused by valves opening and closing). A crankshaft position sensor can still be used to help moderate/determine timing, just that on its own it won't know what stroke its at (it just knows where the piston is!). So just set by the marks and all will be well ;)
 

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it's the depression measured by the MAP (manifold absolute pressure) in the throttle body that gives the stroke information.
BTW there is no cam position sensor on those engines.
Never knew that
Where does the ECU get it's information from to time the ignition and fuel injection?

Edit- sorry I misread that as crank position sensor which obviously it does have and gets its timing information from. :rolleyes:
 

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The CPS is a dial that provides pulses corresponding to teeth. A larger tooth corresponds to the TDC. It produces a larger pulse.
At the same time the ECU is reading the pulses, it monitors the MAP pressure. If the intake valve is opened after the TDC, then the pressure will be lower than the ambient pressure (the second pressure sensor).
 
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