On a coffee overdose, Rich yelled this to Louie about OS Max 45 F:
Hi Rich.
 LG> Problem is, it won't idle worth a spit.  It's got the original OS 4BK
 LG> carb, ya know, the big-bore carb like the more modern SF and FX series.
 RL> The big bore kit definitely isn't helping.  I have an ASP.61 with a
 RL> similar problem.  It's a tradeoff... a big bore will allow very high
 RL> RPM, but kills the bottom end, same as with automobiles or bikes.
Yeah.. at least with cars you can swap flywheels...  the APC props
helped a little, as they are heavier than wood or Master Airscrew, but
not enough.
 LG> I've tried setting the low-speed needle, but still won't really idle as
 LG> reliably as I need it to be...
 RL> I'd replace the entire needle assembly (if you can find it).
Already done... both needles.  No change.  Well, it *did* idle a little
better.
 LG> but it won't idle!  I've been told ringed engines don't make compression
 LG> till they're running -- sounds fishy, I used to have a Honda 80cc four
 LG> stroker dirtbike, and it had PLENTY compression =-)
 RL> I agree... my OS 1.08 and YS.61 have a LOT of compression.  If you
 RL> have ring or sleeve wear, it will kill compression at idle while
 RL> allowing the engine to really open up at the top end due to the reduced
 RL> friction.
Hmm... maybe Tower or some of their cronies have a sleeve and piston for
this thing.
 LG> SO...  what can I do?  Try 15% nitro?  I usually run 5%.
 RL> Definitely.  Even on good engines, I never had good luck with 5% and
 RL> 10% fuels. Expect some drop in top end RPM though, as the 15% will
 RL> cause the engine to run hotter, causing it to expand more and run a bit
 RL> tighter.
Worth a shot.  I'll try this.
 LG> New carb?  I
 LG> can't find it listed.  The SF uses a 4D, I wonder if it'll fit.
 RL> You should be able to use any carb with the same base diameter and
 RL> mounting method.  Pull the old one off and take it with you to check.
The SF series looks identical.  I'll give it a shot.
Email to: sysop@phosphor.datasync.com or gonzol@gfherald.infi.net
http://www.gfherald.infi.net/~gonzol/index.htm
... I am calling from the Bermuda Tria{{{d~~{{{J~  NO CARRIER
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