pulcastro

Guys - My SV (SPE) 26cc Gas engine seems to idle fine, run great, but, everytime I take it up into a hammer head and pull back the throttle to idle, it goes dead stick. Idles great on the ground and during normal level flight. Any ideas on what is causing this issue? Thanks in advance to any help provided.

karolh

Sound like it could be just a bit too lean, so try richning the high needle just a tad and see if that helps. You could also bump up the idle trim a couple clicks for flying and see what happens.

Karol

pulcastro

Thanks - I'll try setting the high needle a little richer, but, the idle is already too high - spec is ~2,000 to 2,500 rpm and I think I'm set at ~ 3,200.

soarrich

My Feedback: (98)

If you engine idles at 3200 rpm you probably have an air leak. Check that the carb is tight, that the carb mounting block isn't broken, if it has a pulse-pressure tube to the carb make sure it's tight and doesn't have any hole in it. Also look at the carb block, on cheap Chinese engines which a SV surely is, look that the brass threads aren't standing proud of the block. If they are put some 200 grit paper on a board or better yet glass, then sand them flush with the plastic. Also check that the gaskets between the crankcase halves is still good, also between the jug and the crankcase.

ec121

My Feedback: (2)

I have an SV26 with the same problem. Idles fine and runs fine. I had the idle too low, but couldn't catch it before it quit after a hammerhead. I knew it was going to do it and forgot to trim the throttle up after takeoff. Had to deadstick the Decathlon and broke the gear block out(cheesy chinese plywood and a two piece landing gear!!). Its probably a tuning problem, but I have just changed oil ratios from break-in to run mixture and will have retune anyway. Someone on one of these forums said he fixed his by removing the carb trumpet. Not sure about that, but I did it anyway. Just haven't had time retune after the repairs and test it out. Maybe this weekend.

pulcastro

Thanks - Keep me posted on the details.

mrbigg

My Feedback: (21)

tighten all the bolts up, including the crankcase. Mine were very loose.