JLMG1971

Hi
I am having trouble with my bigmig 0.061, it runs not too bad, but far from perfect at full throttle and it just dies with low idle. But the worst is that to keep it running on those conditions the needle valve has to be leaned to only 1/8 to max 1/4 out from closed.
The low plug is ok, the prop is either a tornado 6x4 or 6x3, fuel Omega 5% same I use with my other Norvel which runs pretty good.
Any ideas on how to get a good idle and why it runs so lean?

XJet

The idle on my 061 is a little lean -- if I leave the model (a taildragger) sitting on the strip while idling it will stop after about 20 seconds -- but in the air it seems to keep going just fine. If I hold the model with the nose slightly down then it'll idle forever at what I would guess to be about 3,000 - 3250rpms.

You don't say how much running your engine has had or what "far from perfect" means.

These little engines seem to keep getting better and better during the first hour and a half or two hours of running. If you've only got a few minutes on yours then don't worry too much about the idle -- it'll improve.

I've also found that they idle *much* better if you're using a castor/synth oil blend rather than all castor, and if you're running 20% nitro or better.

rrragmanliam

My Feedback: (1)

JLMG

1. Your using poor fuel for this engine. Go with at least 20% nitro ,20% oil. Get yourself some 20% nitro fuel and then add pure castor oil to bring the oil % up to 20%. I run my Norvels on 30 % nitro and break them in on 20%.
2. Be sure the glow head is tight.
3. Be sure you have a good seal at the carb neck to case.
4. 6x4 is a little steep. 5-3 to 6x3 are good ranges to work with.
5. Are the cylinder to case nuts tight?
6. Is the case back plate on tight.
7. Fuel tank,lines clean and in perfact condition.
8. You may want to dissassemble, completly clean and inspect the engine especially the needle valve assembly. You wuold be amased at how much junk comes out of a new or freshly broken in engine.
9 . It should run best at 1-2 turns. 1/8 to 1/4 is waaayyyy too lean.

Hope this helps.

Darren

Lynn S

I would say your fuel it the problem. Norvel recommends 15% nitro to break in, then you can go easily to 25%. I'm using 25% nitro Bryrons 1/2A fuel and my .074 and .049 does fine with it. Be sure to use 100% castor oil fuel.