Heyy all bro s are meeting here.You will see how my mineral oil works great.

Originally Posted by turk1

I just run on the bench my GT9 at home.
I didnt give it full throttle but more than half jumps very good.
My pump is about more than 2" below carb,cushioned with simple soft foam.
Pump have to suck 4,5" high(over my bench tank and fuel line top) from tank and my fuel line distance from pump to carb more than 6,5" (17-18 cm) with loose line.
Pump and carb.worked great.Not at all any bubbles.(Except from carb nipple to back when stopped).I noticed both needles need very leaned.H.S.N. open only 45-50 degrees from fully closed and L.S.N tighten much(at full throttle LSN still in nozzle looking at carb mouth.)
So I recommend several clicks open HSN and more than flush with spray bar LSN to begin.In such position fuel still able to be sucked by carb when carb mouth blocked by hand.
You can check the mixture by squeezing fuel line.I could have a good idling about 2500 +RPM s.I didnt try lesser.
Whew,it was fun...

Interestingly, I was using the fuel pump on the motor side, but was sending much fuel, engine very rich, now after reading this post, put the bomb down the model gave the following settings: low speed needle around a needle and high-speed laps around the 2.5 ... improved engine tuning, and no fuel is flowing, but not yet flown, I test today.

Originally Posted by brace

Motor is still on the test stand as I still wish to put a bit more fuel through at 20:1 before leaning it down to 25:1 and mounting it on the plane. Looking good though.

I wouln't run this engine lower than 20:1 or 5% ~ 7% I have seen many conversions and I know what I'm talking about.
http://www.rcuniverse.com/forum/fb.asp?m=10626717

I agree with Doc. I know same engine as glow and I am using it with %16,6(5:1) full castor.Compare this with less synthetic.What is the reason for lesser oil ratio?Contrarily I think this gasoline system produces more heat to expel.That means better lubrication quality.
Flavinn I recommend you to play around on ground for some time with engine.I found it finicky to adjust yet.I hope better after some run in.Also I asked Michael for 3rd needle function.I hope it may help to have easier adjustment.
BTW; what happened to your plug cap?

Originally Posted by turk1

I agree with Doc. I know same engine as glow and I am using it with %16,6(5:1) full castor.Compare this with less synthetic.What is the reason for lesser oil ratio?Contrarily I think this gasoline system produces more heat to expel.That means better lubrication quality.
Flavinn I recommend you to play around on ground for some time with engine.I found it finicky to adjust yet.I hope better after some run in.Also I asked Michael for 3rd needle function.I hope it may help to have easier adjustment.
BTW; what happened to your plug cap?

3 laps on the high speed needle?? and cover the candle ruined, ruined the cdi but have switched to another ...

My only reason to run a 25:1 mix is just a little less oil being spat out. admittedly at present I am running the engine on a rich setting so I would hope as the engine settles in I can lean that out a bit.

hey guys. I just received a new carb I ordered for this engine from Himodel.com.

I was surprised to see that the whole design of the fuel inlet and outlet nipples have changed positions. I haven't opened up the the new carb yet. I wanted to run the carb first and see if the new design has made a difference before i open it up and start messing about.

check out the attached pictures and give me your comments

Boostoman, looking forward to reading your analysis on this pump redesign.
My motor is off the test stand is now in the process of being mounted on the plane.

Mine and friend' s classic style pump works perfect.No bubbles and pumping function is great.
I think change for cosmetic.(easier plumbing for tank and carb)

I suspect that the fuel pump that comes with the engine is the new style with the inlet and outlet right next to each other. I think then that the other fuel pump is the older style. Having the inlet and outlet on one side of the fuel pump and adjacent to each other makes the plumbing and routing of the fuel lines nicer too. But I can't be sure, it could be the other way around.

Originally Posted by turk1

Here,a synthetic 2 st. oil so expensive that I guess I can buy a new piston/liner set with such saved money after one liter use.
I had a VW Golf Turbo diesel car, it had finished off its engine in 50 K kilometers.It hurt so much that I dont think my tiny 9 CC will do that much.

Oh c'mon Abi..........

OK, after spending alot of time and frustrations trying to get these pumps to work and not succeeding. I decided to see if I could run this engine using the exhaust pressure.

all and behold th engine fires up and with abit a tuning of the HSN i was able to get a good top end. and manage to get a stable idle at 3,000 RPM.
and the transition seems ok. I now will try to tune the LSN so that i dont get all black oil going all over the plane.

Once i sort it out i will try to fly the plane.

here is a vid of the engine running using the exhaust pressure.

NGH GT9 with tank pressure (1 min 9 sec)

Originally Posted by turk1

Heyy all bro s are meeting here.You will see how my mineral oil works great.

Abi your paper towel expense might cover the price difference between mineral and synthetic. LOL Wish strength for your windex and towel :P
Joking for sure

Boostoman, I feel that one can run muffler pressure Ok using gasoline. The fuel tank will have gasoline vapors and exhaust vapors but very little to no oxygen to promote combustion inside. The air to fuel ratio has to be ideal before it will burn. But still there is still some risk of the fuel tank igniting if the conditions are present for it to do so. Gasoline is more flammable than methanol. So just be careful doing it. Anyway I have thought about using muffler pressure myself too.

Hi guys.Similiar like you,I discovered some problematic situations on pump/carb coop.
Reversal to a walbro carb,this pump works (delivers) max. at idle position and less at WOT because of that special carb ' s vacuum positions.Pump and regulator(just similiar as a Walbro carb) delivers max at max vacuum and min. at min. vacuum but carb. produces max vacuum at idle position of barrel. So my try of solution will be to put a restrictive return line at fuel nipple of carb.