30cc = 1.8cid.

I think the big ST has more torque, which is what allows it to swing the larger 20" props. My ST3000 is connected to a MAS 20x6 nylon prop and swings it without a problem, but I think the Moki would have a tough time with the same prop.

hmmmm.... anyone measure the static thrust of the two engines??? using the same prop and fuel

I think you're right about the torque. I bet my ST wouldn't turn more than 8500 with a 12" prop, it just doesn't spin high RPM's.

I think everbody is saying the Moki s a better engine. I REALLY like mine. To get a big Tigre to run somewhat close to the Moki you need to buy it an OS or ASP carburetor and treat it to good fuel. The MOKI is a fantastic engine experience right out of the box .

My 1.8 is on a 300XS. Wow it flies it well.

-Cheech

I think its fair to say that most people who voted on this issue do not or have not owned and run both engines. Nothing like uninformed opinions!

Actually, the person who started this thread did, in fact, own the ST-3000 and currently has a Moki 180 on the same plane. Though my vote is still not verified, I'm expecting considerably more from the Moki than I got from the ST-3000.

My experience with the ST-3000 is somewhat limited. I purchased an old (new-in-box) ST-3000 and broke it in using Wild Cat 15% for 48ozs. I then cut the Wild Cat with straight methonal and ran another 16ozs on the bench. My first and only flight was another 16oz of Wild Cat/Methonal mix. The engine ran great, good idle and excellent transition. I was impressed.

The problem was it ran out of fuel, my mistake, and I ended up deadsticking the 1/4-scale Hanger 9 Cap into a tree. Rather than repair I traded both airplane and engine.

Engine performance with a Zinger 18x8 was good but on that airplane not awe inspiring. She took off 1/2-throttle with no difficulty and could easily do basic aerobatics. It did not, however, have enough to hover that 15lb airplane.

My expectations for the Moki is much more. Initially I'm going to run with a Zinger Pro 18x10 and eventually move up to a 20x6-10 if it makes sense to do so.

Regardless of what everyone is saying here, you are correct. We really don't know until we done a torgue test on the engine using the same prop. Someone also said that to be fair we should use the same fuel. I don't subscribe to that. The big Super Tigers excell with very little oil, the Moki needs a much higher oil content.

I don't even subscribe to the idea of using the same prop, as the engines are designed differently and may produce their best performance with different props. For example, you were using an 18x8 on your ST, but I'm willing to bet it could have swung a 20x8, while I doubt the Moki's ability to swing a 20" prop with the same authority. It seems to be very happy with 18" props.

We will see. As soon as the weather behaves and gives me a chance to finish break in the Moki I'll be able to tell if it will like the 20x6-10 vs the 18x10. My intent is 3D with this airplane and if I can get the 20" prop to swing well it should be a better match for 3D than the 18.

BTW, so far my break in process points at some very respectable numbers for the 18x10 Zinger Pro. I currently have it adjusted for 5+ turns out and have to adjust the throttle to keep it below 7,000 rpm. I'm sure the Cline Regulator has something to do with this -- there is no doubt in my mind that when it comes to the time to lean her out she is goiing to top 9000 with the 18x10 prop.

I don't know the numbers but I'm hoping for between 8000 - 8500 with the 20x6-10 prop. What does that mean in thrust for this 14lb bird?

Don't know about thrust, but if you're five turns out and have to adjust the throttle to go lower than 7000 then you aren't getting it rich enough. With a Perry pump mine is 1-1/2 turns out for flight, and turned a Top Flite 18x8 at 8800 RPM. Since then I installed a Zinger 18x6-10 which performs better. You should be able to get the thing to die by turning it out 5 turns. 9000 might be possible on certain props.

I have owned Supertigers and Moki's. I feel the Moki does provide better and smoother power...no question.

A better survey may be what percentage of ST owners come in DEAD STICK, or have gotten sick of 'em and replaces the carb with an OS.

I had to sell my ST before I beat it to death with a 5lb hammer.

Once I got the needles set on my ST it has not failed me.

My Moki has died a couple times because the low end cap adjusted itself in flight.

My Moki deadsticked today and my new Midwest Cap needs some repairs. Only turned 6600 on the 20x8. Which one am I supposed to like better?
To be fair, I think I had the low end a bit rich. Still 500 Rp's slower than my ST. Should I pump the Moki? Running a Bisson pitts.

20x8 is a lot of prop for that engine. You'd be happier with an 18x6-10.

Gotta repair the Midwest! Would like to hear how it flies. I've been eyeing up their Cap, and it was a real pleasure to build the Extra, so maybe I'll have a Cap somtime in my future....

Probably the best flying plane I've owned. Even with engine trouble I could tell this one is a performer. Almost waterfalls on low rate.

how many gallon/s of fuel did you guys use to break-in the Moki 1.80?

As I indicated above, I think the Cline Regulator keeps me from getting it rich enough to control rpm with the high-speed needle. I say 5 turns because that is what I started with -- was a Moki recomendation. I actually tried to turn it out significantly more and it had virtually no effect. At one point that needle was almost all the way out and the engine was still running 7000+rpm.

I have been very dilligent in monitoring the engine temperature while it is breaking in. 235 degrees is the maximum I've seen at the exhaust header and much less than 200 degrees on the cylinder.

Love Moki ... but have only owned 2.1's ... wonder how the 1.35 performs against OS 1.08 ... my OS has served me well .. but I'm so impressed with the big MOKI I'm thinking of giving my old Cloud-Dancer a breath of new life.

hilleja

You may want to give Jim (cline) a call and run it by him. Jim is a pro at fine tuning and mods for the moki.

My efforts to break in the Moki took a significant turn for the better yesterday.

I did 2 things differently:

1) I shortened the fuel line between the regulator and the carburetor to about 1/2 inch between ends of nipples. This change did not seem to make too much difference.

2) I turned the Bisem muffler rightside up. Up till now I have been running it backwards because I did not have the clearance on the side of the engine case where the engine is mounted to the test stand. I fix this problem by reversing the test stand mounting rail so that the bottom of the "L" runs under the engine. I then moved the engine as far left on the stand as I could get it. This gave me plenty of clearance for the muffler to be installed normally. The difference in the way the engine ran and started was significant.

My guess, was that when the muffler was upside down the thrust from the prop was forcing air back into the engine through the exhaust -- this had a significant impact in the way the engine ran and started. Now the engine starts with a couple of back flips with the chicken stick.

I also found that my RPM readings in the past were no correct -- believe the contrast through the prop confused the tach and made it look like it was going faster. With a Zinger Pro 18x10 I'm getting about 7900rpm full throttle with the needle way out to rich -- I still haven't tried leaning it yet so don't know what peak is yet.

I also found that upon turning the muffler my temperature readings have increase significantly. I'm now seeing 340 degrees at the exhaust header and ~235 degrees on the cylinder head. I hope these readings aren't too hot.

I few times I played with transitioning from high idle to full throttle. Quick spurts up and down work fine but if I allow it to fast idle for a little while the transition back to full is haphazard. I'm still shy of a gallon of fuel and plan to finish the gallon before I try to adjust the engine for flight use.

The biggest improvement todate is the engine is now very easy to start with just a few flips of the chickenstick against compression.

"Contrast through the prop...."

The background in front of the prop (I took the tach reading from behind the prop) was cluttered. I believe this confused the tach and resulted in a false reading. The day-before-yesterday I took another reading from the front of the prop. The background behind the prop was not cluttered -- basically a snow-covered hill. This reading was consistent and I believe correct.