Keno

The gender fluid fluid of choice is tranny oil. I use Rotella T6 5w-40. Cheap enough and works well for a play bike.

Yes, perfectly normal for the oil seals to make it a little harder to rotate.

The pink thing is a labyrinth seal. The orings keep it and the bearings from moving and chattering. You can just CA glue the oring back together, or buy a new one. You can also just smear motoseal around it.

Time sert m8 x 1.25 https://rover.ebay.com/rover/0/0/0?mpre=https%3A%2F%2Fwww.ebay.com%2Fulk%2Fitm%2F282289364765

Time sert M8 x 1.25 https://rover.ebay.com/rover/0/0/0?mpre=https%3A%2F%2Fwww.ebay.com%2Fulk%2Fitm%2F282289364765

Get a head with orings.

Gonna need a picture of what you are talking about.

https://www.jetsrus.com/carburetor/carb_mikuni_VM26-606_carb_exploded_view_parts.html Part #1

Anywhere that sells Yamaha OEM parts. RMATV, Partzilla, ect https://www.partzilla.com/catalog/yamaha/atv/2004/banshee-yfz350s/cylinder https://www.rockymountainatvmc.com/oem-schematic/ You'll be better off buying a used set and having them bored and ported or just buying a setup from Driveline.

Where are you getting the pwk 42?

Interesting choice of words. https://www.urbandictionary.com/define.php?term=smash

I honestly don't know. Try it and adjust as needed. That was just a general range, not a rule. Starting high is usually easier to tune. If it is 4 stroking at the top and midrange go down and repeat until cleared up. If it sounds tinny and down on power, jet up immediately. Ect. Every combination Jets a little differently and differently depending on elevation and temperature.

Verify that the carb slides are opening the same. Adjust with the adjusters on top of the caps.

Read these. https://www.duncanracing.com/s/KeihinCarbJetting-2015.pdf https://www.bansheehq.com/forums/index.php?/topic/99361-what-jets-are-you-using-fill-out-this-form/

You can cut a little off the springs to lighten them, dont cut too much or else you'll have a run away. Or buy softer ones from FAST. You'll need to adjust the jetting. Most run jjh or n68a needles. And like a 45 to 52 pilot and 150 to 165 main. Read the jetting guide from Duncan racing for pwk carbs.

Yep it defaults to curve 4 or "stock" if the selector switch is removed. Curve 3 +5* means curve 3 selected and 5* of static timing. This is the reason the OPs motor detonated and broke. Without the selector, you just flash whatever curve you want to curve 4 and it will be the one running.

Well considering Keihin doesn't make 30mm carbs. Stick with the 28s.

If you want you can clean them. But and 1/8 of an inch difference is the problem.

Yes, the nut goes on the other side per the instructions.

You may just need to sync your carbs. Do you still have tors or do you have a tors delete?

Edit: New chart since it sounds like you are running curve 3. I guess my point is to get the programming cable so you can keep timing down low and pull back up top.

Is there bottom ball joint screwed in? Are the arms installed with the correct sides facing forward? https://teamalbaracing.com/files/recreational-a-arm-standard-travel.pdf

Sound does not equal power. Look at dyno room PC>T5 typically

Honestly, I wouldn't bother replacing the head shell. Just get new domes from your builder as that head shell accepts normal domes.

That's a projected tip spark plug. The electrode hangs an extra couple milimeter into the combustion chamber. Don't know if it's benefits anything. I'm with Sully though, a 6 heat range is probably too hot. Go with an br8es.