Can anyone tell me if they have had any experirnce with this engine inverted? I understand from some of the comments in the reviews section that the tank has to be kept low. Unfortunately, I think mine will be rather high. I wonder if it's going to be a problem? Would a pump help?

Thank Guys!

Richard

A pump always helps!! I have inverted the Saito and the OS .91 and .70 without any of the problems you hear about. I just set the center line of the tank even with the center line of the engines carb. So far no loading up or flooding.
It takes me A while to get the engine tuned just right when inverted though. I set it up on the ground then fly it A little, land and adjust the low end A bit more until I have that sweet spot. I keep the low end just at that almost too lean spot.
To date I have never had A dead stick or load up and I'm not A needle twister. I get them set and leave them alone. Come winter I may have to fatten up the high end about four clicks.
Before inverting I make sure the engine has been broken in and not just on A bench. I used to use A big Cub but have started using an old Kaos for this. Once broken in correctly they are easy to tune and you aren't chasing the needles.
I like my pumpers because I can install the fuel tank anyplace I like so I set them right over the CG. That's why I prefer OS and YS over the Saitos but the Saitos are great engines.

I wonder if I can invert my Du-bro fuel tank. Is so doing, the hole of the tank will be lower than the carb. I'm using the tanks that have that protruding end on it.

Richard

I don't think inverting the tank is a good idea and it will not help. You need the center line of the tank close to the center line of the needle in the carb. If you are running tank pressure that can help a little.

and like it was said a pump can fix the tank issue.

If you can keep from putting the engine completely unside down, like move the head over a little off inverted it will help a lot. 15 degrees or more makes a big difference. I did a satio .50 like that and it worked well.

another problem witha inverted engine is exta fuel running into the engine can put out the glow in the glow plug. A lot of inverted engines ( again the ofset 15 degrees helps ) have to have a on board glow driver to keep the engine running through out the flight.

I have 2 Saito 100s, one in a U-Can-Do with a high mounted tank and one in a Harrier 90 with it even with the tank. 15/4W APC props. Both are excellent runners and there was, and is, no fiddling with the HS needles. I run both with an F plug very rich with a long smoke trail and have never had a flame out or kick back. On the U-Can-Do I had a minor siphoning issue prior to starting but I looped the supply line up around the top of the cowl and that cured it.

Saito is my brand.

Stick 40 : Will the angle affect the pergormance of the engine at all?

Richard

The engine doesn't know what angle it's mounted at. What 40 is saying is by installing it just off by A few degrees it can sometimes help to keep the fuel from putting out the glow plug if you don't quite have the engine in proper tune or the tank draws A little.
Setting things up correctly is the best answer but sometimes you just can't so you can do little tricks to make things work.
I have A nice on board glow driver but I have never had to use it. Some day I may build A plane that for one reason or another will not allow me to set things up perfectly and need it or some other tricks like canting the engine A few degrees to make it run well.
I have an old GP 60 size Aeromaster that was like that but I used the SK .91 two stroke engine in that plane. For some reason this engine isn't too tank sensitive and I got away with it.
Today with all the ARFs set up problems are becoming A normal problem with the cheaper ones so old tricks are coming back in vogue, good things to know.

Good info guys. All very helpfull.

Bu the way, I HATE ARF's. They suck! I only build wich I'm proud to be a dying breed.

Richard

I have a saito 100 in my hanger 9 spitfire it is mounted inverted and has been broken in that way but I also use the hanger 9 plug and use pro 20 omega fuel it runs very well and idle's very well and I use an 14x8 prop a very good runing Engine

I have an inverted saito 100 in a hanger 9 p51. The tank center line is just above the carb. The issue I am having is after running a 1/2 tank of fuel the engine loses power. When the engine is shut off (or dies) it is found to have very little if any compression. The high end needle is set so that a good smoke trail follows the plane. It is getting hot but I dont understand how it could be lean with a good smoke trail. The low end maybe a little lean as to idle good but when the plane is in the air I might get 1 good flight and the on the second flight the engine does not seem to have the power it should. (15% wildcat fuel 14x8 prop)

The prop size and pitch seem good and fuel should be ok. A slightly lean low end shouldn't matter. How's the airflow over the cylinder and head? If that's good I'd look for kinked fuel lines, dirty filter, and especially the muffler pressure line and tank seal to make sure you have consitant good pressure in the tank. If it's got an air leak you could be leaning out near the end of the tank causing engine damage. let us know what you find. Expo