thanks guys - i appreciate the responses. let's see - in reverse chronological order:

will rob - no - this engine doesn't have the disc - i guess it's not that "old"

maelstrom - thanks - i reference that site quite a bit and was attempting to follow his directions. the problem is that he assumes you can get to a low idle (2,500 or less) after setting the high end and that is exactly my problem heh.

myway - i hadn't heard about the "high compression" .80's but it's funny, because i was struck initially at how hard it was to turn over by hand and assuming it meant pretty good compression. i've got some 10% nitro kicking around from my trainer days - i can give that a whirl. i'm a little suspicious about the cool plug syndrome as i've tried OS F plugs and the McKoy 4 stroke plugs that came with my .91 as well as leaving the glow plug on while attempting an idle to no avail. i will try using the 10% nitro and let you know how i fare.

hobbsy - i haven't really noticed any difference in the smoke when it dies. i get a pretty healthy amount of white smoke while it's running and then it just starts to shake a little bit and quits. in general i'd say it doesn't run nearly as smoothly as my .91. i've started with the low end screw as rich as even with the barrel and it does seem to come down as i lean it out but i just can't it slow enough. i will get to the point (about 3 or so turns in) where leaning it more actually makes it run worse so i'm really at a loss. a couple of times when adjusting the high end it seemed to bog down the more i opened the throttle but then that went away and i couldn't really replicate it. to be honest i haven't gone back every time i adjust the low end and re-test the high end. i got the high end to about 10,600 or so with a 13x6 prop then backed it off 300-400 or so. i've always thought (erroneously perhaps) that you could run 4 strokes a little on the rich side without too much of an impact on the low end.

w8ye - i've used an F plug as well as a couple others and 15% nitro. we adjusted the valves to be on the wide side of the recommended range (.1 mm). they were kind of a pain to set as the threads on the valve screws seemed real coarse/ not exact - not sure if my .91 is like that as i haven't had to mess with those.


Does anyone have any feedback on part 2 of my question if i decide to bail/send this engine in to horizon? will the saito .72 fit the footprint of this engine (i.e mounting holes and throttle hook-up)? what about other engine brands (OS, Magnum etc.)?

Thanks in advance for all the help - the season here in VT is waaay too short to spend this amount of time messing with an engine!

Boneman