The B engine timing for this dummie
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Topic: The B engine timing for this dummie
Posted By: 2011dandd
Subject: The B engine timing for this dummie
Date Posted: 29 Mar 2019 at 5:50pm
Hey guys
I have the manuals so I can refer to those as and when I need to. Honestly though I learn and understand more by the way you guys put stuff.
So with that said. After giving the b a good service I would like to go through the timing and make sure or check it’s all good and adjust as need be.
Wondered if those of you out there that know far more than me about these things could steer me in the right direction?
Cheers folks
Dan
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Replies:
Posted By: Dick L
Date Posted: 30 Mar 2019 at 9:36am
It is really easy with the valve cover off while adjusting the valves. If your magneto is hot and throws a spark, with both rocker arms up the instant the impulse snaps the TDC or some CENTER line is in the center of the inspection hole it is in time. If it is not in the center of the inspection hole the magneto can be rotated to place the line in the hole.
There is several other ways people get it in time but this is the fastest way.
All four cycle engines static time at top dead center. When the timing mark is in the center of the inspection hole one of the pistons is at top dead center. When both rocker arms are up on a cylinder it tells you which cylinder is at top dead center and ready to fire that cylinder. You will want this to happen on number one normally. How ever if it is sending spark to the cylinder that is on top dead center with both rocker arms up it would still be in time. That either confuses some or makes the process easier to understand.
When your engine has the TDC line in the center of the inspection hole two pistons are at TDC. One is on the compression stroke and the other is on the exhaust stroke. One more revolution to TDC sends the other two pistons to TDC with the same conditions. The next revolution sends the first two pistons to TDC with the opposite piston on the compression stroke with the other rocker arms up.
When the TDC is in the center of the inspection hole that will also be where you want to set the valve clearance on the cylinder that both rocker arms are up.
This is also not the only to set valve clearance but doing it this way while learning will etch how the camshaft operates the rockers to open the vales in time.
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Posted By: 2011dandd
Date Posted: 30 Mar 2019 at 2:12pm
Thanks Dick
Very informative, appreciate the time you have taken to explain all of that.
Wish I had more time to spend on projects and getting really familiar with engines. When the kids go to school next year I’ll have lots more time on my hands.
Thanks
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