rsieminski

225g/8oz. Rpm with the .21 after 3 tanks, with 2.5% nitro, 18%(50/50) oil:
MAS 8x3 17.7K
MAS 9x4 14.2K
Right now, it's only about 5% better rpm over the bushed LA .15. At this point: idle is good, midrange is a little rich, and peak is good. It still needs more break in time, because the needle is still REAL touchy.

EDIT:
2 more tanks through.
I go a new MAS 10x4 and got 11.6K-11.8K
I removed one of the head shims and got another 200rpm.
so:
MAS 10x4 G/F 3 Series 12K just under peak.

Maybe too much prop fr the little .21? ...and still not broken in yet. There is such a difference between straight and level, and nose up. A few more tanks maybe. I'm going to try to fly it tomorrow, and do loop after loop to aid the break in.

sarpet

MA 8x6 14700rpm 10%nitro 18%oil

buzzard bait

Really good numbers for such a small engine, and even on larger props. Does it seem OK on the 10x4, not overheating?

I was very tempted by this on the Hobbyking website, but when I went to buy and saw 30 to 40 bucks shipping I folded. Maybe sometime when I have more to order from them.

Thanks for posting,

Jim

buzzard bait

I realized afterward that the super high shipping cost was due a few extra items that ran up the weight, so I scaled back my order and paid $15 shipping. Well worth it since the engine was only $40, and I still got a few micro servos within the weight limit for the shipping price. Looking forward to trying out this engine when the weather warms up!

Jim

rsieminski

Good luck with it. It's a nice little engine. Post up some RPM figures when you get it broken in. I don't think it's a screamer, I think this one like larger props.

buzzard bait

It will be awhile...it's snowing and in the 20s right now. But I'll be happy to post figures once I can get out in decent weather and put it on the test stand. Glad to hear it likes larger props; that's how I like my engines.

Jim

buzzard bait

Ran it up for a few minutes today: 10% nitro, 22% oil (1/2 castor), OS A3 plug: 13,800 on old style MA 9x4, sometimes just going over 14; 15,000 on Bolly 8.5x4; won't try larger props till it's had a little more run time.

Contrary to first post, I did not find needle unusually sensitive; actually I thought it was perfect. Throttling was quite good even after very short run time: reliable idle below 3000, hesitated but didn't die when I snapped throttle wide open; adjusted low speed needle several times to improve transition and it became very good. It would not snap from idle to full instantly, but was just slightly slow...not what I would call a hesitation at all, but just as if you advanced the throttle quickly but didn't snap it. This may get even better as the engine is run in, but it's very good right now for anything except 3D (not that I do 3D anyway).

Muffler is very small...just an 1/8 inch longer cone than the muffler that came with the .12. Exhaust outlet is larger than on the .12. Otherwise they look identical.

Starting is instantaneous with a choked flip or two first. Great hand-starting; no starter needed. But I had to heat the head with my heat gun at first because the pinch at TDC was quite tight.

I love it!

Jim

jeffie8696

That hesitation is common in engines with a very large bore carb. I think too many manufacturers are trying to get that last hundred rpm on the top so they can brag about how their engine is so much more powerful than the other guys.
Iwould rather see a great throttling engine than one that just makes top end. Sounds like you got a winner though.

buzzard bait

It isn't a hesitation as in a pause, it's just a very slightly slow response compared to the best of my engines (it's not as good as my ST S25). And it's only run a few minutes. I like the power, and I think the carb is very good, and it may get better.

Jim