ORIGINAL: the mother of invention
I have a 34cc Briggs & Stratton Fource 4 cylcle motor converted for aircraft. I made a spacer for the carb and cut the spring tension back on the throttle. It will run at idle or with the choke almost closed. I thought it may be sucking air. Checked the gaskets and they are not leaking. I think when I trimmed the spring for less tension that without the tension it leaks in air around the barrel. Any thoughts on changing the carb or fixing this problem.
I don't want that spring tension on the servo all the time so would like to find a more RC friendly carb with less tension and easy movement.
Thanks,
Eric
I have yet to convert my engine but I intend to try a different carb. While the one provided will get you to around 5500rpm (tested on a friends 'stock' conversion) I think some more rpm is required and probably more tunability. My intention is to try a Walbro taken off a Ryobi 31cc (I have several from conversions), if that carb can flow enough for a 31cc 2 stroke at 7000rpm it should flow plenty for a 34cc 4stroke at approx 6000-6500rpm. The nice thing with the Ryobi Walbros (at least the ones I have) is they have both a high and low needle and are not compromised by being an EPA model.