YM 186 Timing Mark location?

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hrtull
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YM 186 Timing Mark location?

Postby hrtull » Wed Mar 31, 2021 6:03 pm

I am wanting to check the injector timing on my YM 186. I have read all I can about the procedure and understand the steps. In all of the reading and googling I cannot seem to locate the timing marks. Some information says it is on flywheel so I took a small oval inspection plate off on right side just above the fuel filter. After rotating , it appeared to me there were no marks there. Others indicate it is on the front crankshaft v pulley on front of tractor behind radiator. That seems the most logical but I cannot see a stationary marker/indexing tab . I was unable to find marks on that pulley but wanted to know if this is where they are before I start steel wooling/cleaning pulley to locate and possible radiator removal for access. Any help greatly appreciated, Thanks HRtull

winston
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Re: YM 186 Timing Mark location?

Postby winston » Thu Apr 01, 2021 4:30 am

I doubt you can tell much from my picture and it is out of the 169 manual. Only guessing your marks would be very similar.
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hrtull
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Re: YM 186 Timing Mark location?

Postby hrtull » Thu Apr 01, 2021 12:31 pm

Winston, I zip tied a piece of scotch brite to a paint stick and cleaned off crank v pulley with engine running. Pictures show what I found. Two marks per cylinder with each set spaced at probably 120 degrees apart. I assume one mark is TDC and other a numerical degree BTDC indicating correct timing. I cannot locate any type of stationary pointer/marker for the reference marks on pulley. Was hoping to find this engine same as the the attachment you sent me but it is different. Dont know if there is a line etched somewhere on block near the pulley. Every youtube and google search never shows this type of pulley markings. Thanks for your reply. I am hoping someone else may have a similar set up, Have a great day, HRtull

hrtull
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Re: YM 186 Timing Mark location?

Postby hrtull » Thu Apr 01, 2021 12:33 pm

Pics for previous post
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winston
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Re: YM 186 Timing Mark location?

Postby winston » Fri Apr 02, 2021 5:43 am

A little rambling. Try taking your #1 injector line loose at the pump, rotate engine following your timing directions. When you see the fuel start to move you can know you are close to the correct position with the pulley. At that point look closely for a line or indicator of any kind that is close to lining up with the BTDC line on the pulley. Hope that makes some sense.

hrtull
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Re: YM 186 Timing Mark location?

Postby hrtull » Fri Apr 02, 2021 8:08 am

That makes perfect sense . Thanks for the suggestion. Now that you have mentioned that I need to adjust valves after a few hours of run time after engine work. I assume I could place #1 TDC/compression stroke, while doing valve adjustment then start cleaning/searching near the pulley #1 marker line . If I find it then I can do the #1 injector line test. I will let you know what I find. I was looking for clues of a broken marker but nothing found. Thanks for turning the light bulb on. HRtull

hrtull
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Re: YM 186 Timing Mark location?

Postby hrtull » Fri Apr 02, 2021 2:54 pm

Winston, I kept reading and reading. I found what I was looking for in an old post with picture of yours that I have attached. Buried behind the oil sending unit per your picture is that arrow. I took a closer look with some brake cleaner and a brush and there it was. I had no idea that the mark would be so far away from the pulley markings, seems a little too far.. I do understand what you did to get a more accurate reading and will do something similar . Anyway, I appreciate all your postings. Would not have found it without your help, past and present. Have a good day, HRtull
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winston
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Re: YM 186 Timing Mark location?

Postby winston » Fri Apr 02, 2021 5:10 pm

Well good, I think I clamped that stick in there to help me get things lined up better.


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