Bobbing oil dip stick?

[TobyU]

Not a good test at all. Most do that and lots of blown head gaskets do no
no worst. Never had one blow the strick out hard.

Many will start to smoke if you open dipstick.
Best test I have found (because comp tester etc should be left in toolbox for autos lol) is to get it warm and then go in three tight circles to the right, then three to the left, then three to the right again...
If you don't fall off..... Look for your house through the thick blue/white smoke!
If no smoke....gasket isn't that bad bad.....yet.

 

[Forest#2]

Thank you for that. I'm going to save that Sawsilla website. Looks like they've got good prices.

I just recently stumbled across that sawzilla site.
I ordered some Nikki Briggs stuff recently from them and shipping was only like $3.50 and tracking # provided and a fast shipper to me.

Tip about replacing the itty bitty jet o rings.
install the jet on a wire such as a straightened out paper clip and then take a needle nose plier (so you do not stab yourself with the sharp o ring pick) use a o ring pick and break the old o ring off then lube the replacement ring and use back of finger nail to get one side caught in the groove and then just roll it on around using back of finger nail.

I bought some Nikki Briggs jet o rings from this guy before and they work great, seem tougher than the ones in the kit and fit the jet grooves good). Some of the kit jet o-rings are too fat for the jet groove and emulsion tube.

https://www.erbay.com/itm/163674198748

When installing the jets I also use the paper clip wire to guide the jet onto the tube then I use a small nut driver that is little smaller in diameter than the jet and hand press into place. (nut driver is hollow inside so the guide wire goes up inside as a alignment guide for the little jet)

 

[PTmowerMech]

I just recently stumbled across that sawzilla site.
I ordered some Nikki Briggs stuff recently from them and shipping was only like $3.50 and tracking # provided and a fast shipper to me.

Tip about replacing the itty bitty jet o rings.
install the jet on a wire such as a straightened out paper clip and then take a needle nose plier (so you do not stab yourself with the sharp o ring pick) use a o ring pick and break the old o ring off then lube the replacement ring and use back of finger nail to get one side caught in the groove and then just roll it on around using back of finger nail.

I bought some Nikki Briggs jet o rings from this guy before and they work great, seem tougher than the ones in the kit and fit the jet grooves good). Some of the kit jet o-rings are too fat for the jet groove and emulsion tube.

https://www.erbay.com/itm/163674198748

When installing the jets I also use the paper clip wire to guide the jet onto the tube then I use a small nut driver that is little smaller in diameter than the jet and hand press into place. (nut driver is hollow inside so the guide wire goes up inside as a alignment guide for the little jet)

The old o-rings disintegrated. The nut driver is a good idea. I have used an extra 2 cycle carb adjusting tool, lubed with

BTW, "erbay?" You mean ebay, right?

 

[TobyU]

I just recently stumbled across that sawzilla site.
I ordered some Nikki Briggs stuff recently from them and shipping was only like $3.50 and tracking # provided and a fast shipper to me.

Tip about replacing the itty bitty jet o rings.
install the jet on a wire such as a straightened out paper clip and then take a needle nose plier (so you do not stab yourself with the sharp o ring pick) use a o ring pick and break the old o ring off then lube the replacement ring and use back of finger nail to get one side caught in the groove and then just roll it on around using back of finger nail.

I bought some Nikki Briggs jet o rings from this guy before and they work great, seem tougher than the ones in the kit and fit the jet grooves good). Some of the kit jet o-rings are too fat for the jet groove and emulsion tube.

https://www.erbay.com/itm/163674198748

When installing the jets I also use the paper clip wire to guide the jet onto the tube then I use a small nut driver that is little smaller in diameter than the jet and hand press into place. (nut driver is hollow inside so the guide wire goes up inside as a alignment guide for the little jet)

Sounds like you're installing the Jets the same way I do which is kind of hard to describe but if you're holding the carburetor and it's normal orientation you would be dropping them down the middle too. You just have to make sure that they go in properly and you seat them in the hole..
A lot of times I find this is put in from the bottom and not from the top..
Apparently this happens from the factory because I have had multiple ones where people swear it's never been worked on or serviced but yet it's stuck in the bottom which can fall out and be sitting in the bowl so that's why I feel it's a bad way to install the jet. But it will work either way.

 

[awkerper]

Where does the extra pressure come from, since the only way from the combustion chamber to the sump is either through the valve guides or passed the rings.

Piston rings don't make a perfect seal, so there's always a certain amount of "blow by" gas that sneaks past the rings. This is why the engine has some kind of ventilation system - on automotive engines, it's called the PCV valve (positive crankcase ventilation). If this vent is obstructed, the pressure can be enough to lift the dipstick out of the tube.

 

[PTmowerMech]

Piston rings don't make a perfect seal, so there's always a certain amount of "blow by" gas that sneaks past the rings. This is why the engine has some kind of ventilation system - on automotive engines, it's called the PCV valve (positive crankcase ventilation). If this vent is obstructed, the pressure can be enough to lift the dipstick out of the tube.

Right. I get all that. Located under the flywheels. But that's only to relieve the pressure in the crankcase. Pressure in the head gets pushed down into the crankcase when the headgasket between the valves and the push rod valley, upon explosion in the combustion chamber.
This is more than the PCV can exhaust.
So with a bad headgasket it'll come out the PCV, the vented fuel filter and anywhere else it can find. As Bert noted, if the oil cap isn't secured, that's the least amount of resistance, so it's going to go there.
The video I posted, I'm almost positive is normal. To make sure, I did the same thing on an engine I knew had good head gaskets.
My confusing was just how much bobbling the oil cap would do with or without a blown head gasket. Bert says it would jump a lot more than what mine is doing if the headgasket was bad. Which makes sense, since the explosion is contained inside the head, and the only bobbing the oil cap is doing is just the normal pressure of the pistons up and down stroke.

 

[PTmowerMech]

Sounds like you're installing the Jets the same way I do which is kind of hard to describe but if you're holding the carburetor and it's normal orientation you would be dropping them down the middle too. You just have to make sure that they go in properly and you seat them in the hole..
A lot of times I find this is put in from the bottom and not from the top..
Apparently this happens from the factory because I have had multiple ones where people swear it's never been worked on or serviced but yet it's stuck in the bottom which can fall out and be sitting in the bowl so that's why I feel it's a bad way to install the jet. But it will work either way.

I knew something was up when I removed the bowl and the jets went laying in the bottom of it. They're supposed to snap in. Give a little click when inserted properly.
The guy who showed me this first, said to install them before putting the tube onto the carb, as to not smash the rubber gasket below it.
That rubber gasket was almost none existent when I removed the tube.

I think the problems this engine had were no less than 2. Water that had collected in the fuel pump. (probably from pressure washing after each mowing, because it's stored inside the garage at all times) And the bad internal gaskets. Which may have also been caused by the water.
But the bowl, even though it had a little water in it, didn't have the white corrosion that most do that's been water contaminated.

 

[PTmowerMech]

I posted this on the wrong thread. So here it is on the right thread.

Just incase things don't work out with the rebuild, I got a new carb from Briggs. I probably should've went with the Stens and just swapped out the jets, if need be. It was about $80 cheaper. But the owner of this is a multi millionaire. And has kept my brother in work for over a decade now. Plus this mowers home is about 2hrs away. It's gotta be right the very first time. And stay that way.

Briggs has an online store now. I may start getting a few things from them also, just to try them out.

Briggs online store.

 

[Forest#2]

Sounds like you're installing the Jets the same way I do which is kind of hard to describe but if you're holding the carburetor and it's normal orientation you would be dropping them down the middle too. You just have to make sure that they go in properly and you seat them in the hole..
A lot of times I find this is put in from the bottom and not from the top..
Apparently this happens from the factory because I have had multiple ones where people swear it's never been worked on or serviced but yet it's stuck in the bottom which can fall out and be sitting in the bowl so that's why I feel it's a bad way to install the jet. But it will work either way.

I have the plastic emulsion tube in my hand or on the workbench, not on the carb when installing the jets. Using the little hollow tube nut driver and the wire allows for straightening a crooked press if watched or looked at afterwards closely. Some will want to seat slightly cocked sometimes.
Yes I've seen some that go in from the opposite direction. the emulsion tube has to be off the carb for them.
If they are laying in the bowl or gone (sticking to tyhe bottom of your shoes) they went in from the bottom. (and you did not see them fall on the floor)

 

[Forest#2]

You asked me???
BTW, "erbay?" You mean ebay, right?

Not sure of your question, I do not see the typo
sometimes referred to as flea bay or FLEECE bay.