The Kayfun 3.1 is the same as the Russian, not to be confused with the Russian 91%.
The 3.1 and Russian are a bit larger....or should I say, taller. This is because it has an extra part below the deck.
It has an overflow juice well, in case you get a little flooding, the juice will travel down the airhole and drop into the juice well.
It also has an adjustable 510 center pin, which the kayfun lite does not.
Side fill port, which is a pain in the ... to use sometimes.
Now onto the Kayfun Lite and the R91%.
The KFL and R91% do not have that extra juice well, so they are a little shorter.
If these leak down the airhole, juice has nowhere to go besides coming out the air intake hole at the bottom of the atty.
Personally, this is not of concern to me, because when these are built properly, they shouldn't leak at all. Unless under extreme weather and or altitude/pressure changes .
The KFL does not have an adjustable center pin or adjustable airflow controls.
This is where the 91% beats the original KFL, as it has both adjustable center pin AND airflow control.
The clones of these can be hit or miss.
Most of them work well, but some of them have crappy threads and screws that can easily strip.
If you're hamfisted and or not mechanically inclined, you may have issues with some of these clones.
Some may require extra patience and a little fiddling.
Good example is the fill screw and chimney on the tobeco clones.
The fill screw is dumb, and can be easily stripped out.
The threads on the chimney are rough and can be a PITA to work with.
All the clones will show up dirty, with excess machine oil in them.
They will require an extensive breakdown and cleaning.
EVERY atty, whether clone or not, should be cleaned before it's first use. My 91% had light machine oil in it and required cleaning.
But, my clones (I have 10 of them from different makers) require you take cleaning to the next level.
One of my tobeco clones had huge chunks of metal shavings ( swarf) in it. The center pin/airflow tube was completely filled with heavy oil and chunks of swarf.
Here is what I had to do to clean my clones.
Completely disassemble, I mean everything. Anything that can be unscrewed needs to come apart.
Every oring needs to come off.
The center pin insulator on the top of the deck needs to come out. (easy to do)
I did not attempt to remove the insulator at the bottom of the 510 connector though.
All orings got dropped into a coffee cup with hot water and dish soap to soak while I did the rest of the cleaning. I put the clear plastic tank into the water/soap with the orings.
Took a small coffee cup and put all the parts into it.
Filled it with 99% iso alcohol. Would have preferred pure grain alcohol, but we can't have that in california.
All the screws and small parts went into a shot glass and filled with 99% alcohol.
There everything sat for about a hour.
I agitated the cups every 10 minutes or so.
I then took an old tooth brush and scrubbed the parts while they were wet with the alcohol.
Be very careful when cleaning/rinsing the small parts. You don't wanna drop one of those down the drain.
I usually plug my sink, and put a large bowl over the drain to catch anything I may drop.
Back into the alcohol they went.
About 10 minutes.
Then they come out and get rinsed in hot tap water.
Some people go the extra mile at this point and boil them. I don't feel the need to though.
NOW, everything gets laid out onto a paper towel.
I take my tooth brush and squeeze some dish soap onto it and scrub 1 part at a time.
Rinse the part in hot water, then onto a fresh paper towel to dry.
Repeat this for every part!
I rinse the tooth brush and reapply soap for each part.
You need to clean down the airholes as well.
I used a piece of twisted up kanthal and got inside of there. Blow through the airhole and repeat.
Once you've done this to every part, you are ready to wrap and build.
Hope this helps. I feel like I left something out. Probably did, but maybe not. = )
