Wood chip fuel.

[oil pan 4]

I was going to use my honda gx390 or get another predator 459cc.

[oil pan 4]

If I break this I give up.

The engine is getting replaced by a 1.25 inch bearing bridge.

[oil pan 4]

It lives, again.
The gx390 had a 104 main jet in it when I got it, which is way too big. Tried a 100 and ran that in the stump grinder. This time when going g over the carb I took it from a .45mm air bead to a .38 and tried it with a #100 main jet and that was too rich, the next size smaller that seemed appropriate I have on hand was a #95. The 95 was better but still a bit rich.
I think some soft skull mechanic got ahold of it, one of those people who thinks if it's not running right it always needs more fuel.

[Piotrsko]

Or he could have been a couple thousand foot lower in elevation.

[oil pan 4]

Have to go over 100 miles straight east to see a significant elevation drop.
There's 2 out door toy shops that do it to ATVs and such here locally. The "it's not running right it needs more fuel" belief appears to be wide spread.
White smoke, need more fuel.
Blue smoke needs more fuel.
Black smoke, needs more fuel.
It won't start because the engine floods, needs more fuel...

I want the engine to run lean enough it will die when I first start it unless I give it some choke for the first 10 to 30 seconds.

Next smallest size I have is an 85 I think that's too small. So I bought an eBay set with 85 through 100 jets, specifically 85, 87.5, 90, 92.5 a redundant 95, plus a 97.5 and 100 that I shouldn't need. I'm thinking it needs about a 90.

[Piotrsko]

Hmm mechanics trained in mechanical diesel fuel injection systems. Or You tube. Or not at all.

[cRiPpLe_rOoStEr]

Originally Posted by Piotrsko

Hmm mechanics trained in mechanical diesel fuel injection systems. Or You tube. Or not at all.

Farm boys who did some makeshift fix to their fathers' trucks and agricultural machinery once in a while, and think the same basic principles would apply to anything else?

[Piotrsko]

Something like that. Worked a couple of times, can't remember the causes of the fails where it didn't, results in add more fuel.

[oil pan 4]

My gx390 was missing an o-ring on the air bleed orifice insert. It was allowing a ton of extra air into the emulsion tube, which was pulling more fuel into the engine under light load.

[cRiPpLe_rOoStEr]

Originally Posted by Piotrsko

Worked a couple of times, can't remember the causes of the fails where it didn't, results in add more fuel.

Back in my school days, once a teacher inquired the class about how to raise the temperature of an engine by either leaning or enriching the AFR on a spark-ignited engine, and the only one who said leaning was me, and I was right.