WD45 Engine Diagnosis Needed - UPDATE Nov 3

I don't hear much of a problem but you may want to do a compression test to see how close all the cylinders are to each other.

Thanks......I'll do both! Won't get to it until next week due to travel schedule.

I hope the copper wires help - honestly hadn't thought of that as a cause but it surely could be. Will report back!

mine runs loud too. i wear ear muffs when i use it. not talking about the exhaust either. even the gears are loud. i think thats just how they are!

My WD sounds exactly the same at idle or low load.
I was checking compression ,ignition,carb rebuilt,new intake manifold ect. but never really found a problem.
   When it gets under a load and the governor opens up all that goes away and it pulls strong so I quit worrying about it.
   

Is it distributor or magneto? Distributor should have a working centrifugal advance so the ignition timing is retarded for idle speed and advanced for full load speed. If its stuck advanced which seems to be typical for an old engine because of springs rusted off or lack of lubrication (a few drops of oil into the felt in the hollow shaft under the distributor rotor every few months) it will knock at idle but run good at full speed. If its stuck retarded, it will run smooth at all speeds but not have anywhere near rated power at full speed and the exhaust will run hot at full speed. That can burn the exhaust valves.

Check with the distributor cap off. Turn the rotor in the direction it turns with the engine running and it should allow some motion and snap back when released. If not its time for more work deep in the distributor.

Oil on spark plug threads could be from oil in the cylinder from worn piston rings or intake valve guide but it should be showing blue smoke in the exhaust from burning oil, or it could come from a leaking rocker cover gasket dripping oil down the side of the head at the plug. Leaky rocker cover gaskets come with overhead valve engines, sometimes even new ones.

Gerald J.

... and if you are using Champion spark plugs, replace them!

I would also say start with basics. Fresh plugs with correct gap set, and I have had the issue with wires too. Like others said make sure they are the copper solid core and not suppression core as the suppression core just adds resistance for the modern electronics you don't have to worry about on old tractors. They need all the current the ignition system has. I also agree with checking the cap and and rotor for wear or corrosion. 

Thanks for all the advice. I'll dig into this when I get back to Massachusetts.

They way it sounds to me, I would do a regular tune up, make sure it has fresh gas and add a half can of Sea Foam, put a 53 SC plow behind it and work the pi$$ out of it for a day .  You might need 10 or 15 acres for that 

You have received a lot of good suggestions.

Have you checked the inlet or screen of your sediment bowl, to make sure it isn't partially plugged?

Put a pertronix electric ignition in, your problems will b solved.

Thanks to all of you.......pretty sure I've got strong fuel flow to the carb and had thoroughly cleaned the air cleaner. Replaced the missing tube from the air cleaner to the carb with no change in the way the engine runs. But both worth checking. Will add the Seafoam treatment to the list!

Edited by Dave(inMA) - 27 Oct 2016 at 2:47pm

I't take the dist off, and take it to a good electric rebuilder shop.  They have the tools, and equip, to do it right, and access to the parts.  If the shaft wobbles enough to close the points, its overdue...