Spark plug gets gas fouled every cold start

[steves snapper]

Keep an old piece of 3/8 to 1/2 glass around to sand on. If you don't have any, have a glass shop near you cut one from a scrap piece. Will make an excellent inexpensive flat plate. You can also roll pushrods on it to make sure they are not bent.

good tip on the glass how much larger than head should the glass be? thanks sgkent

 

[sgkent]

I keep a piece of old flat tempered glass around that is maybe 12" x 18". I can't afford, nor do I have space for a machinists flat table. Works good when gluing flat things together too. Put some clear packing tape on it and set the item to be epoxied on it. Just fixed something last night that way. Perfectly flat. You want a piece of glass that you can make left - right, forward - back, figure eights on while rotating the head. Easier to do that horizontally than on a window like someone else suggested. Also if the glass is sitting on a reasonably flat surface, it will flex less than a window might.

 

[steves snapper]

I think this could be the torque sequence

first pass 6LBs 2nd 12LBs 3rd 18LB then after first mow torque again to 18LBs.

 

[sgkent]

torque us usually a crisscross pattern from the inside out, done in two or three stages. It helps to balance the clamping.

 

[slomo]

Retorque after a couple mows as well.

 

[steves snapper]

torque us usually a crisscross pattern from the inside out, done in two or three stages. It helps to balance the clamping.

your absolutley correct about starting in middle working way outward some of the ytubers are giving alot of missinformation like one Guy sanded old gasket w/ a stainless steel wire wheel then torqured in a circle.
most ytubers give good advice. thanks sgkent

 

[steves snapper]

Retorque after a couple mows as well.

OK I will retorque then 18LBs even after a few mows. you know that mite be why the gasket blew. remember I reused from my orginal engines head an gasket, all I did was snug w/ regular racket (of course from middle to outside kindof) then tighten on 2nd pass.
next attempt I'm more educated thanks to you nice ppl sharing the knowledge.
additionaly now I know what the valve stem cap is it's exactly a cap that sits ontop of the locked valve stem. this image

I will double check to see if these caps are there. I do know I have then on the replaced head so I have spares. thanks again slow mow. I get the new carb maybe Sunday. plan to definity changing the fueled oil. will all the oil drain out w/ snapper flat or will I have to elevate the front some?
Please refresh my memory on valve lash setting IIRC I set both intake an exhaust to .004? also recommended spark plug gap?

 

[slomo]

OK I will retorque then 18LBs even after a few mows.

18 ft lbs sounds kinda' high?? Some of the others hopefully will verify proper torque value on the head bolts. 15 ft lbs rings a bell for some reason?? I know Briggs upped this value. Think it was for the Inteks which are known head gasket tossers.

you know that mite be why the gasket blew. remember I reused from my orginal engines head an gasket, all I did was snug w/ regular racket (of course from middle to outside kindof) then tighten on 2nd pass.

Yes. Probably no lapping the first go around and old gaskets. Makes sense to me.

next attempt I'm more educated thanks to you nice ppl sharing the knowledge.

That is what we are here for. You are welcome.

additionaly now I know what the valve stem cap is it's exactly a cap that sits ontop of the locked valve stem

Yes again. Don't lose the caps or the lash will be waaaaaaay off. Well not the lash but valvetrain geometry to be precise.

I get the new carb maybe Sunday. plan to definity changing the fueled oil.

Fix the carb FIRST. Make sure she is fixed then dump the oil.

will all the oil drain out w/ snapper flat or will I have to elevate the front some?

I put a 4x4 block on the fronts and one on the right rear. This angles the mower and raises the front a bit. You can do it flat. SAE 30W is your friend. Stay away from multi-grade oils for air cooled engines like these.

Please refresh my memory on valve lash setting IIRC I set both intake an exhaust to .004?

WITHOUT looking yours up, "typically" they are 0.004" INTAKE and 0.006" EXHAUST. Download your engine manual for the proper specs. There are a few great people on here that hoard tons of mower documentation. Hoarding meant in a good way.

also recommended spark plug gap?

Again typically they are 0.030". Some are 0.020". Your engine manual will tell you.

 

[slomo]

How I replace a head gasket.

1.CLEAN the engine like a new one PRIOR to opening her up. This limits "most" the grit from falling inside. Think hospital clean as Bert's Mobile used to say. De-carbon the engine as your manual states.
2.Lap head and block area where gasket sits. 220 if it is really warped, 400 then 800 wet/dry paper on my garage door window. While lapping, use an OPEN finger grip to lower the pressure on the head. Do figure 8's letting the PAPER do all the work. Not your fingers pressing on the head. When the paper gets quiet, not removing material, progress up in grit number.
3.Clean and lap the valves in while you are there. Behind the valves too. Little valve grinding compound will seal the valves.
4.Spray Hi-Tack sealant on the gasket, both sides.
5.Reassemble as normal. Retorque two mows later.

5

 

[steves snapper]

update: way to cold to be outside fixing the snapper, I recieved new carb. there was an extra small black plastic piece not sure what it is? carb appears decent. hope it works.