C/CA backfire and surging

-plug should be changed... looks dont count..

1,2,4,3 is how they are hooked up, I checked both ends of all plug wires, and grounded all 4 plugs then rolled engine over, all showed good spark.

I think I'm gonna check that manifold gasket tonight, it's time to pull the hood off anyway to get a better look at things. Valves probably need set anyway. I will try to get some better pictures of it as well.

Many thanks for the advice.

Edited by Jgranat - 12 Jul 2021 at 8:17am

It looked like it came out of the carb Fred but I don't know for sure. Could have been both, I will look closer tonight. It was random as far as I could tell, not like it was every revolution.

Edited by Jgranat - 12 Jul 2021 at 12:33pm

As Steve mentioned, put a set of plugs in it first. And not Champions!  You'll give yourself more problems!  LOL!  NGK's or Autolites will do just fine. A crappy set of plugs will do all the things that it's doin'.......

Sound advice from one and all. Thank you very much! I sprayed starter fluid around the manifold tonight while it was running and the engine smooths right out. Off with hood and some quick impact wrench work had the manifold off, the studs securing the manifold to the head at rear of engine were rusted badly enough they could no longer secure the manifolds properly. The two stud holes in the head are in good shape, some new studs and a manifold gasket should get us back in shape. I will report back when I have this fixed. New plugs and a carb kit are coming as well. Governor rod hole line up well when checked too.

Best part is my boys helped me diagnose it and break it down, it's tarped for now.

I hope this solves it. I bought this tractor for the kids. I told the oldest boy we were going to work on it after supper and the youngest boy went and told the middle one, all three of them were in on it.

timing mark is on the side of the flywheel housing , a 1 inch hole to look thru... With plugs out, roll motor over until it starts to come up on compression #1 cylinder ( finger over the plug hole.. as your roll up slowly, you will hear the mag  "SNAP"... look in the timing hole and you should be at TDC.... it will advance to FIRE after startup.

Found a bent push rod on #2 exhaust. I appreciate all the suggestions but my gut was right. It sits a good inch below the end of the adjuster, time to dig in and figure out why. It is almost like there is no lifter under it, it sits that low.

YEA... tap on the top of each valve stem and see that they all POP up and down without any lag........ If you straighten the rod, does it "FIT" then ?  Lifter should not come out of the hole with cam installed... Sticky valve is a more believable cause .... hate to see you open the block/ cam for a valve problem.

I have worked over a couple of bent push rods and reused them... have to lay on a straight flat steel plate and check it for true... Work slowly with a hammer and it can be done... didnt have replacements available at that time and needed it done now.

You could "assume" everything was OK and one valve stuck from setting. If that valve now POPS up and down easy......... i would just startup and see how it runs !

Edited by steve(ill) - 18 Jul 2021 at 8:53am

how to time an FM mag.

RUNNING!!

Straightened the push rod, set the valve lash, properly assembled and timed the mag and off she went. Still have a few bugs, but i'd top up the fluids and mow with it, it needs to work.

Thanks again one and all for the help, my 3 sons thank you too. They were all involved in lending a hand.

Edited by Jgranat - 20 Jul 2021 at 8:05pm

@Dale (Stonelick); Ingenious! Any idea what those brackets were for originally? Thanks.

loooks like the little metal peices you get to hang christmas lights