ffdq

My Feedback: (4)

hey guys,I have a zenoah g-26.It has about 5 gals through it,getting about 8100rpms with a 18/6 runs great but very little vert.Is it time to lean out the high end.What should I be looking for in rpms?
thanks Fred

buck1856

My Feedback: (49)

Put in G26 rpms or G26-props in the search bar in the lower right hand corner of the first page you came to and look at all the posts.Most guys where using an 18x6 mentzik,and if i remember right where getting at your rpms or a little more.But it depends on elevation.How much does your plane weigh.

mikenlapaz

Check the color of your spark plug tip. You are looking for a coffee with cream, lite brown. Darker may be rich. Lighter probably too lean.

hanko

I have five G-26's. The best prop Ive found for all around performance is a wood 16-8. I think your over proped. Im looking 9000 on that prop, right in the power band.

karolh

You were a bit sketchy with your information. It would have been good to know what model is the engine in and how much does it weigh, plus what brand prop are you using. However if you are using the stock muffler which is very restrictive then your rpm on that size prop is fairly reasonable, but switching to a 17x6 or 16x8 would be much better. Using an aftermarket muffler will give a significant improvement in performance of at least 600+ rpm, and ideally you should prop the engine to run in the 9,000 rpm region.

Karol

arobatx

Carbon Mezjlik 18x6, 9000rpm on any decent aftermarket in cowl muffler like Abell, B&B, Slimline (slightly less rpm)...etc. If you are running the OEM muffler, you'll want to replace it, this is the single source for most of your power loss, aside from improper tuning. APC 17x6 or Zoar 17x7 are decent, less expensive props.

arobatx

LOL...when that happens Karol, it just cracks me up.

karolh

Times two Chad.

Karol

ffdq

My Feedback: (4)

Hi guys,the plane is a great planes super sterman and the wg.is about 14.5lbs and the prop is an apc 18/6.It flys great good power,but the vert is weak.The muffler is an aftermarket in cowl looks like a b&b.
thanks Fred

arobatx

The APC 18x6 is heavy, I'm not surprised at your RPMs. If you want to use APC, put a 16x8 or 17x6 on it, and you'll see an immediate difference. You'll need to retune however.

blkbird68

My Feedback: (19)

The vertical is never going to be what I would call great at 14.5lbs on a G26. I would definitly follow arobatx's suggestion and ditch the APC prop. A good light wood prop would be be my preference.

karolh

The fact that the model not only weights 14+ lbs but is also a bipe, which by design generates a lot of drag makes the possibility for a good vertical with your combo rather dim. However as Blkbird suggested using a reasonable priced but good performing wood prop like a Xoar 16x8 or 17x6 should give a much improved vertical performance.

Karol

Blade-breaker

My Feedback: (4)

Mine was turning the exact RPM with the 18-6 APC. Here is a link to a previous post on it.

http://www.rcuniverse.com/forum/m_77...tm.htm#7742612

blkbird68

My Feedback: (19)

BTW, I still haven't run across that Bisson muffler.

Blade-breaker

My Feedback: (4)

No problem. Thanks for remembering [sm=regular_smile.gif]