47 BN, timing help needed

spf150

Member
Hi,

I'm trying to get a 47 BN timed. I have a rebuilt magneto from EBay.

I went thru the timing process, lined the marks, pushed the magneto at the engine, cranked the engine over by hand to TDC again. I went to pull the magneto away from the engine and went thru full range of travel but there was no click from the magneto. I rotated the engine a bit more and it popped but the marks are definitely off.

Could this be a governor issue, a flywheel not lined up or am I doing this wrong?
 
Pull the mag and check if the rotor is lined up with the tower on the cap when it fires you can make a mark on the body where the tower is but the rotor has to be there when it
fires
 
The impulse will snap when its installed whether or not correct. But to have the mag installed correct is have #1 piston at the top you can see with a lite if its at the top. Then the rotor should be pointing to #1 tower on the cap. Cap is marked such. Impulse can be at all four cycls one at a time. But for sake of being in time best way to install is having #1 piston at the top on compression . Make sure you are on compression. The mag will be in time if done correct or it will be 180 out as there is a slot for the mag to enguage so you are either in registratiion or 180 out. My self when i pull a mag i turn engine till #1 has snaped then make sure the rotor is same position when i put back in. If carb and plugs are OK thos engines will fire and run easy on the first rev.
 
In regards to the timing process...

As I understand it the tractor is timed when
the marks are at TDC and the magneto is
pulled away from the block until it pops. If
I don't get that pop will it run? Or just
run poorly?

I've read that the notches on the governor
need to be at 8:00&2:00(which they are) when
the timing marks indicate TDC.

Thank you guys for helping out the newbie.
 
One last question.

Is it possible that the timing mark on the
flywheel is wrong? IE:Somebody in the past
didn't install the flywheel in the correct
orientation.
 
Cant install it wrong you need #1 on coompression mite need to remove valve cover to make sure both valves are closed.
 
Thank you.

Definitely at TDC, verified with the timing
marks, dowel on the piston as well as both
valves on #1 closed.

My question for now:

Is it a deal breaker if the impulse doesn't
snap on the mag? While rotating the mag by
hand(while loosely bolted to the tractor) at
#1 TDC?
 

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