What oil is best? and what ratio?

[RedGas]

SPOIL SPORT!

 

[mdavlee]

So....I picked up 2 Craftsman 2.0 / 10" saws made by Poulan. Both run great but one has a bit more compression. Anyway I'm cleaning them both up and putting all the best parts on the best power plant for my keeper. I was going to sell the other but I decided with only $12 into each saw, I can sacrifice the lesser of the 2 to my little experiment. Ill be able to run lean ratios of the Saber with a load. It will have to wait till after the spine doc cuts me loose fully. Probably in March. Until then I'll pull the jug, check out its guts to make sure its worth testing. No bearing or scored part surprises ect. Ill take pics of the piston and cylinder for you peeps to scrutinize b4 I proceed with testing. Anyway, a question for those in the know on 2 strokes. If I pull the jug and end up trashing the base gasket, will doing a base gasket elimination using high temp rtv cause issue with a reed valve engine in a negative way? I know it often helps power on a piston port but no idea on the reed set up. I can also make a base gasket if need be.

You just need to make sure you have sufficient squish so you don’t kiss the cylinder head with the piston. High tempt rtv works if it’s perfectly clean of gas and oil. I used it for years. I use loctite 518 or the permatex equivalent. Motoseal from oreillys or another auto parts store works fine too.

 

[TreeLife]

How many thousandths are we talking on squish.? Minimum? Use solder as a "plastigauge" then measure thickness.

Yes. Most like to see between .015 and .025 it seems depending on what one is shooting for?

 

[mdavlee]

How many thousandths are we talking on squish.? Minimum? Use solder as a "plastigauge" then measure thickness.

Yellow plastigauge works great. Just make sure there’s a little oil or something to break the bond on the piston. Or small solder works fine. .020” or more is good.

 

[mdavlee]

I may have thinner solder. Came in a butane powered mini torch kit.

You want the .032” at the most. Roll the engine over several times to make sure it compressed it completely.

 

[andyshine77]

Ok fellas. Round 2. Went right to 200:1. Saber and 90 rec fuel. Going for another gallon at wot no load. Tiller warming up right now.

Seen engines run quite awhile without any oil under no load. What rpm is she spinning? Most are limited to pretty low rpm.

Neat experiment BTW[emoji106]

 

[andyshine77]

Ill do this with a saw eventually in use.

[emoji106]

 

[Terry Syd]

Without the load you aren't pushing heat into the piston, plus you don't have a lot of side loading on the piston. Just a bit of oil will provide the lubricity you need to keep from sticking the engine. I expect if you are running high revs that you will burn out the rod bearing before you seize it.

 

[Leerod83]

Without the load you aren't pushing heat into the piston, plus you don't have a lot of side loading on the piston. Just a bit of oil will provide the lubricity you need to keep from sticking the engine. I expect if you are running high revs that you will burn out the rod bearing before you seize it.

I agree. See what she does buried in the dirt. I don't see it lasting long under a good load. I do enjoy the testing though so keep it going. I also want to see a rod hanging out of it lol.

 

[smokey7]

I think I have three of those home lights if you need parts and I'm in Michigan also

 

[smokey7]

I'm in Madison Heights michigan 48071. I'm just running it still. I did pull the muffler on the blower and the 3314 saw. I just retune and run them.

 

[smokey7]

Yea I think it will take far too long with no load at 100:1 to kill it. Honestly I think bearings will go first. Tuned properly is key

 

[N8TE]

100% smeared right on the boot

 

[N8TE]

Is that to be used as mix oil or am I to smear it on for wind protection? I've heard of the vasoline on the skin deal for cold. Not sure how much truth there is to it though.

Skin still gets cold...helps with wind burn though

 

[porsche965]

I've really enjoyed this thread.

 

[Terry Syd]

The coating is worn off the land between the transfers, feels sand blasted.

Probably a manufacturing defect, I don't see any related damage to the piston. The damage to the top of the piston is not something I've ever seen before. Perhaps the engine had been stored with some water/moisture in the cylinder that corroded the top of the piston.

Weird intake, I wonder why they just didn't take the 'bridge' all the way down to the bottom of the port, then flatten out the intake port. The bridge would prevent the skirt from hanging up and they could have speeded up the opening.

 

[Terry Syd]

How about running it on ATF? That would be an interesting test.

 

[Terry Syd]

The reason I mentioned ATF is this is an 'oil thread'. If ATF at 50-1 will keep an engine running (and I expect it will) then a lot of this 'which oil is best' may come down to issues other than lubrication.

 

[RI Chevy]

I'd like to see Motul 800

 

[Terry Syd]

Just try the old ATF that has been lying around. The stuff is hydroscopic and has probably picked up some moisture. If it lives on that, then it would live on the brand new stuff.

I should mention, there was a fellow on a dirt bike forum that admitted he didn't know what lubrication to use, so he used ATF in his Hodaka for over a year before he discovered two-stroke oil.