CrazyHerb...

How to measure thrust at the low-low...various engines on your planes of choice, with max pitch props...have your buddy stand with his ankles holding on to front of horizontal stab...start and throttle up... ...at full throttle for three mins...if he has 1/4 inch horizontal dents in his achilles, that's' about 12 tp 15 lbs.thrust with an 18 cc...if the dude turns ashy white and starts crying and his Reeboks are quickly filling with blood... then thats' a twenny five pounder or so...with mebbe a Ryobi or Homelite 32cc..

I'm no expert by a long shot, but I do so enjoy messin' with the little engines...I don't even fly yet...I'm too busy building airplanes that would go with my latest conversion...If your interested I'll let you know how to use a common house cat as an automatic orientation guage, or tachometer....Me bride thinks I'm nuts...as you all know that would be interpreted as my having a very high IQ...

Let me get a little serious here now...I am retired... 63 years old, and a seven year Parkinson's patient...I build and convert for therapy...some of my better medications I feel, are working in my shop...Again I am a novice at this...all I can offer are my experiences...

Ist engine...Weedeater 18cc...which is actually a shop trophy...ends up when cutting and grinding off extra shroud metal, I smooth cut away my magneto bracket...no s___! at this rate I'll be flying when Star Wars is real...Next was a Homelite 28cc...conversion stuff from Carr Presciion... plane is ME-109, 13 1/2 lbs; plan a llltle difficult to read as I got them off a Russian web site...wheeling a 16/8 prop at 1/3 throttle the lillle plane flys like a champ...can't wait till I feel confident enough to go it alone...

My choice of engines would either be a 28 cc Weedeateer off a Featherlite gas trimmer...or a Homeliete 32cc for bigger planes bigger engines?... I just haven't had any expeerience...yet...maybe next week...I thought the Ryobi 31cc was a convertor's dream machine with the carb working off that reed valve in the crankcase, and the muffler sittin' above it all in a line, would make for an easy mount to cover with narrow cowls...the problem I have with Ryobi is the garldarned crank and connecting rod are stamped metal talk about getting by on the cheap...I had one in a Spitfire I just finished but was knocking when I tried to start it...removed the back crankcase plate and saw the stamped stuff...the crank was made of strips of steel held together with what appears to be wrist pins.. bottom line ie when the crank shaft rotated it would hit the pins...thus the knock...wherin now sits a Homelite 32cc...

Some maybe helpful hints...

Use a drill press to drill series of inline holes to remove aluminum... seems to go faster than just cutting and rinding...

Save everything attached to engine... parts may come in handy some day...

Tighten propeller very securely... a back fire whenstarting can shear the magneto fly-wheel pin, which is cast aluminum...

Those zama carbs aren't Walbro... use a velocetiy stack to increase rpm...they'll work just fine...

If you pull the piston from head...be careful getting it back in you can easily pop the ring...

Reconditioned Ryobi grass trimmers at Harbor Freight for 49.00 plus shipping

Reconditoned Weedeater Featherlite trimmer from E-Bay 44.00 plus 14.00 or so shipping

When the traveling tool shows come to town, go early...good source for Weedeaters under 50.00

Lost the web site but McCullough sells engines outright rebuilds for 20.00 or so...some outfit in kansas City

Wacker Engines for converesion kits his prices arr lowest I've found and he could use the business Peter Faith owner...


Gotta little windy here so I'll sign off...


Thanks for everybodys help and hail to rc universe...


Remember "We're all here because we're not all there"'


Sethlakai


I used to have all the questions...and I still do...they're just different questions.