Setting Yanmar 1GM10 to TDC

[Jonny A]

Hi everyone. I want to check the valve clearance on my Yanmar 1GM10. The procedure looks simple enough (I have a copy of the service manual), but I’m not sure how to get the engine to TDC. I know what mark to look out for, but how do I physically turn the engine over to get it to the correct position? I don’t have a starting handle, how else can I turn it over once I’ve set the decompression lever?
Thanks in advance.

 

[LadyInBed]

I don’t have a starting handle

Sacrifice a 1/2 or 3/8 drive socket. Cut a slot in it so it fits in place of the starting handle.
It doesn't have to be angled for it to self disconnect if you only use it for this job and use a ratchet handle to turn it.

 

[andsarkit]

27mm / 1 1/16" socket or cranked ring spanner on the crankshaft nut holding the alternator belt pulley on.

 

[VicS]

Hi everyone. I want to check the valve clearance on my Yanmar 1GM10. The procedure looks simple enough (I have a copy of the service manual), but I’m not sure how to get the engine to TDC. I know what mark to look out for, but how do I physically turn the engine over to get it to the correct position? I don’t have a starting handle, how else can I turn it over once I’ve set the decompression lever?
Thanks in advance.

According to the the manual I am reading, by turning the crankshaft with a wrench on the crankshaft pulley retaining nut

.

 

[VicS]

If you cannot easily see the marks to set tdc turn the engine until the exhaust valve is just closing and the inlet valve is just opening . Then turn 1 full turn . That will be tdc again but with both valves closed.