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Buzzacot Farm Pumper Rebuild

Scotty 2

Registered
Hello Mr Muzz
By winding the rod up making the exhaust open early, you also let the valve close later which means lower compression doesn't it?
It could be a weak spark. Can you check to see if the spark jumps about 5 or 6mm?
On our engine with the Wico, we had spark but I noticed the magneto was not 'snapping' as our other EK Wico's do. It sounded lazy.
By loosening the 2 bolts that holds the magneto on and tilting and moving the magneto slightly it got to a spot where I heard the familiar 'snap'.
I had a listen to the video of our engine I posted a few pages back. Sadly the governor sound drowns the magneto sound out.
There's a good paint free contact from the back of the magneto to the mounting plate and from the mounting plate to the engine? If you have a multimeter just check the resistance from the magneto frame to the head where the plug screws in.

I'll get some mixture needles out later to take some pictures. It sounds as though your needle is not tapered over enough length. It should not have ridges either.

Flames out the exhaust....gunna have to try that one. :O

Cheers Scott
PS: Been up to the shed. All of our mixture needles have the taper running over a length of 6-8mm up the shaft. The slighter the taper, the better the adjustment control but you have to be careful that it still screws down enough to close. They're not that long those needles.
 
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muzzery

Registered
Hello all.
I’ve already posted this in another spot, but I wanted to attach here to kind of complete this story. I guess that way anyone that googles and gets to this will find the finish. I’m very grateful to those who helped me with tech advice , it was paramount to my finishing.
Also a big thanks to a few of you who sold me hard to find parts.👍👍👍
Now what to do next? Perhaps a yb southern cross I’ve been paying off, and matched to my big southern cross piston pump..
Here’s the video
https://youtu.be/JzyPvOOt6RM
Thanks
Murray
 

Wozza

Registered
That's pretty tidy Cobbadog. I like the glitz. I notice you have a top muffler fitted. How quiet is it? Does it tone down the pop you can hear mine making in the video? I was thinking of fitting one to mine as with the angled down pipe (stock?) exhaust I find a lot of exhaust soot on the bull wheel that takes a bit of getting off after a days running. I suppose I could just point it up to run......
 

cobbadog

Registered
Hi Wozza, with the top muffler in place it still barked like a dog. Since that photo was taken I changed it over to a B&S mower muffler and that shut it up. Just one of the small round ones.
 

Scotty 2

Registered
Hello all
Those pumpers shouldn't be having any popping out the top pipe. Isn't it only there to breath to keep the engine cool when in miss mode? Any restriction of the top pipe would hinder cooling wouldn't it?
If it pops and farts out the top pipe I'd be checking compression and timing.

I should give this one a run. I don't think it's been started for about 4 years.

Cheers Scott

 

cobbadog

Registered
Hi Scotty, it should not be barking but this barker has always been the same and shoving the extra muffler on has shut it up. Compression is good and spark is timed to the SPARK mark on the flywheel and it starts very easily. What do you suggest?
 

Wozza

Registered
I can't find anything on the theory of the auxiliary exhaust port engine design but I'm thinking it would increase the 'miss' time significantly as the still expanding gas on the power stroke would dissipate most of its residual energy via that bottom port thus reducing the energy required to push the exhaust gas out via the exhaust valve. On subsequent 'miss' cycles the piston is pushing up against closed valves so the air should act like a spring and help push the piston back down once it goes over TDC. Does anyone have anything on farm pumper type engine design? There is probably a dusty file on it in the US Patent Office from about 120 years ago.
 

cobbadog

Registered
Best theory I've heard is that it aids in cooling the air cooled engine. When it is breathing through the top on the miss strokes you can feel how the air gets slightly cooler each time. It certainly is different.
 

Scotty 2

Registered
Hi Scotty, it should not be barking but this barker has always been the same and shoving the extra muffler on has shut it up. Compression is good and spark is timed to the SPARK mark on the flywheel and it starts very easily. What do you suggest?
Valve timing?
Also worth checking is the inlet spring tension or inlet valve and seat. If I remember there's a spark on each revolution of those particular pumpers. Maybe some fuel been sucked in for some reason when in miss mode and the partially obstructed 'breather' port (creating slight vacuum and compression) or exhaust port is enough to allow a pop? I dunno. I'm only a broken down sparky dude.
I suppose even a weak spark could cause another fire when the piston is up the top on the exhaust stroke. Unburnt fuel?
Oh crap. I'm going to have to go and have a stinky beak at the pulled apart Southern Cross out at the farm now that curiosity has me. It's been a long while since looking inside a farm pumper.
Oi Cobba. You made your muffler didn't you? Maybe not enough clearance between the 2 plates making it too restrictive?

Is the pop only on the first revolution of the miss cycles or do they pop on each revolution of the miss cycles?
 
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cobbadog

Registered
Hi Scotty, mine only barks on the hit stroke and no other time. The muffler I mad eto shut it up is on my horizontal 2hp Buzacott and it is quiet as a mouse now.
After the McDonald I will have to look at Flo to try and sort it out. Valve timing should be ok as it starts so easily, Not sure how light the spring tension is on the inlet but an easy one to test and adjust, compression appears to alright though never measured and as for timing the magneto, that might be out of my ability to find the flux and set the cam lobe. Then the drive gear for the magneto on Flo is not fixed on a keyway and I feel that maybe the wrong gear or not I.m just not sure.
 

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