Originally Posted by
cdrc1
Use Sullivan filters on all my planes and on field box fuel bottle. Have replaced the glow plug at least once and using a 4-stroke plug as recommended by Saito. The prop is a 14x7. Perry pump is a VP-30 regulating pump. Will try leaning the low side some more but have tried that once and it did pop and threw the spinner/prop.
cdrc1,
with the 14X7 you are running your Saito 100 in a bit higher RPM range, well there are 3 things to say about that,
A) being a 4St your engine loves to be loaded more than a 2St would, and
B) Saito's are Camed to be loaded more than other brand 4St,
C) a correctly loaded engine is easier to tune, so you may wish to try a 14X8 prop to get your RPM down a bit,
I have seen engines that ran very badly because they were simply loaded incorrectly for the Plug and Fuel that was used in them, and a simple prop change to a larger prop fixed the problem in an instant.
1) engine 1 was a 160 4St with a 13X4 prop on it, the engine would stall as the pilot would come off the throttle to land or as accelerating to lift off, I sold the guy a 15X8 and his problem went away instantly, yet he could have gone to a 16X6 or 8 but no one had one,,
2) this engine was a .61 2St, it had a super light wood 9X4 prop on it, the tow guys worked 3 hours on it and it would stall every time (every time) when the wheels left the ground, I told the guy to put a APC 12X6 on it and he did, problem gone instantly,,
both of these^ engines could have been fixed in a different way, but it was not acceptable to their flying styles, and that was if, if they added a much colder plug and ran fuel with maybe 40% Nitro or higher.
Jim