DaOldGuy

I have been through near 2, 6 ounce tanks and there is no idle, it has to be kept upward 8K and above or it just craps out. You can take the throttle all the way down in short blurps but you have to jump back up or it will die. Looking for a level set here, do they all start out this way and get better with some runs of is this motor <or operator> missing something?

Billsky

My Feedback: (37)

How many 6 oz tanks through the engine would you say to get a reliable idle? Just checking, All of the engines are giving me fits.

the pope

Ooops there should be a space in there . head shims . They added another one on the later produced ones I believe . I would only check them out if all other attempts at getting the thing to run right failed . Mine also had heaps of swarf init and maybe some is in your carby etc . Cant remember your issues . Cheers

joescottsdale

I have now turned the engine right side up. I was able to get it to start and run with the glow starter attached. Still runs really rough and then dies after a minute or so. I'm not even trying for an idle yet, just trying to get it to stay running. Once running, there is some brown oil coming up from one of the glow head screws. I've convinced myself that the glow head gasket(s) are bad, but don't have the tool yet to open it up.

I plan to contact the compay and see if I can get some new glow head gaskets.

For clarification, I was always trying to start the engine right side up. But with the engine mounted inverted like it was before, the plane had to be upside down. With the fuel tank upside down, the airline was submerged in fuel and would sometimes siphon out fuel, this was fixed with a loop in the airline though.

Charley

My Feedback: (2)

That's a typo, he meant "head shims it's."

Mine idles like a dream right out of the box. The main reason for all the bent rods, IMO, is the error in the instructions about the number of turns out the HS needle is supposed to be initially. The engine floods at that setting & it can develop a hydro-lock. If it does and you spin it with a hefty electric starter you can bend the rod.

CR

hsukaria

Well I finally got myself a GX40 used from a guy at the club. He gave up on it and gave it to me with the understanding that if I get it to run well, I would give him one of my old Thunder Tiger 75 4-stroke. That is a good deal for me since I have 2 of the Thunder Tiger 75s, One of them from another club member who gave up on it and didn't want it. So you can see that I am scaling up step by step.

Anyway, I have been keeping up with this engine for a while. The previous owner blew the head gasket and replaced it with a new one. The question I have is how many head shims should I have in it BESIDES the head gasket? I have the head tool and the long needle valve that I use for my glow AX40.

Anything else I should watch out for? I am sure that previous owner did not follow the break-in instructions. I will go through the procedure anyway. I hope the compression is not compromised!!!

DaOldGuy

I have an update on mine. This dang thing has been a PITA, and not limited to the motor its self.
A buddy handy with Glow motors came over and we pulled the Carb off. Nothing on the carb was tight including the HS needle assembly. Checked the Head and Cylinder bolts and they all were over a quarter turn from snug. That in its self was an improvement, but it still was not right.

Well its time to break the rules and touch the LS needle even though the manual says factory preset and no adjustment needed. 1 quarter turn lean and it became a different motor. the LS is real touchy, after that a couple minor tweaks and the world was better. It still had random issues at an idle that is would just change RPM one way of the other, like trying to trim a plane in flight that has a bad servo.... Ah yes... Bad servo... I have never seen an HS-81 in that bad of state. With the TX and RX on you could move the servo with your fingers and there was no resistance toward you of any sort.... It was toast. With that all fixed now, this week end with tell.

hllywdb

hsukaria,
You should have 1 gasket (thin gasket material) and 1 shim (metal). That being said I have run them with all combinations, depends on the motor. But can't go wrong starting with a shim and a gasket.

Don't forget to lock down the screws on the head AFTER tightening it with the tool. As enough people have noted, needles are touchy so make small adjustments. It's high compression so flooding it and hitting it with a starter will bend the rod.

hsukaria

Got it, thanks. I still have to mix the fuel, it won't be for another week or a few days to run it. I also don't have an inline fuel filter, gonna get one. I do have the long HSN on my AX-40 that I am going transfer it to the GX-40 to make it easier to tune. I purchased the long needle originally just to extend it out of the cowl, but I can glue or solder an extension to the short needle instead.

hllywdb

Use the long (or short) one from the gas, it has a slightly different taper to the needle and gives you a finer adjustment.

hsukaria

I can't find the post now, but I need to purchase an inline fuel filter. What are the recommended filters for this engine (from tank to carb)?

the pope

Hey there Husky , I dont use one and its no issue . I do however have a filterclunk in the gas can as well as inline filters one after the gas can pump and another just before the end of the line . Cheers the poope

hsukaria

I have everything ready for me to start running the GX-40 that I acquired from a friend who couldn't get running. In the process of mounting the engine to the test stand, I realized that the HSN o-ring is damaged. I just ordered a new one from NV engines. Meanwhile while I wait, I have a long needle valve that has a very gradual profile. It looks very different from the short gas and short glow needles. I do see that the two short needle versions have obvious differences in profile. But I am wondering if the long needle will work for now? I only see one long needle being sold by NV Engines and am wondering if it is supposed to work for both glow and gas. I guess I could try it anyway.

Charley

My Feedback: (2)

Is anyone flying this engine in the Escapade? I have my Escapade about ready to fly with the NV gasser & I'm kind of concerned that the engine's carb is slightly above the top of the fuel tank. Don't need any flame outs on vertical lines.

I'm thinking about laying the engine on its side to get the carb on the fuel tank centerline. No room in the fuse to raise the tank appreciably.

CR

hsukaria

I have been flying an Escapade 40 for about 7 years now with about 5 different engines, including the Norvel AX-40. I plan on installing my newly acquired GX-40 in the Escapade this week to fly it. I have never had any fuel tank level problems with that plane on any engine that I installed.

BTW, I did get the GX-40 I got from a clubmate to run properly yesterday. It had a damaged needle valve o-ring and I temporarily used the long needle valve from my AX-40 until I receive the new o-ring from NV Engines.

Charley

My Feedback: (2)

Thanks for the info. I'll just have to try it. Glad you got your GX-40 running right. Some users recommend the nitro HS needle for its longer taper.

CR

hsukaria

I compared the standard length HSNs for the gas and glow. The gas version is more gradual. However, I received it from the previous owner with a chewed up o-ring. That is why I used the LONG HSN instead, which is very gradual and some have said it makes it easier to tune. When I receive the new O-ring from NV Engines, I will switch back to the short gas HSN.

Charley

My Feedback: (2)

Cranked my GX-40 up in the Escapade yesterday. Won't run right. When the engine is stopped there are air bubbles traveling from the carb into the fuel line at the inlet nipple (the nipple is pointed slightly upwards). Got to figure the O-ring on the HS needle is leaking. Ordered parts today.

I was going to order a nitro HS needle but they're out of stock! No maiden this weekend!!!

CR

hsukaria

I read in an earlier post here that putting an inline fuel filter will help eliminate the small air bubbles. That's what i did. I installed the GX-40 on my Escapade yesterday, no flying yet. Our club is having an electrics-only fun-fly this weekend.

I also received the new HSN o-rings from NV Engines today and installed it on the short needle and needle into the engine. I will have to tweak it again now that it is installed on a plane and with the different needle.

earlwb

Before you think that you have an air leak. Here in the hot Texas summers, the gasoline can vaporize when heated a little more. Thus those bubbles may not be air but actually gasoline gas bubbles forming as it vaporizes. The carburetor could be getting heated up too much from engine heat resulting in the gas bubbles forming. If the bubbles form when the engine is stopped, it may be quite all right as it is just the carb getting too hot. I do not really have a solution for it as I get the problem with my gas engines in the summer too. With some of the engines it results in a vapor lock occurring. Usually after flying when I cut the throttle to land, the engine stops as the wheels touch down. When I look at the fuel line I can see the bubbles forming there at the carb too. When I touch the carb it is quite hot too. Some other guys with big gas engines that have rear mounted carbs and a rear mounted muffler have it even worse with the carb getting hot and vapor lock or the gasoline forming gas bubbles in the carb too. But later when it is cooler the engines run just fine, and you can taxi on back to the pit area no problem.

On some days when it is really hot, about the only thing that flies is gliders. No motors nor engines on them. You hand launch or use a high start launcher. The engines just do not want to run. The electrics ESCs and motors over heat. I used to go out and fly in temperatures like that, but as I get older and older I become less and less enthused to go and do it.

As the temperatures go up the air thins out more and more, it results in the engines and airplanes not wanting to run or fly well as the air behaves like you are at higher elevations. We actually have some full size Careflight helicopters that cannot fly when the temperatures go over 105 degrees F. In the Middle East, the big airliners have to postpone flights as they can't take off safely when the temperatures exceed 125 degrees F. You see it sometimes with the private airplanes in other locales too where they can't fly until the temperatures drop down.

In any case it may simply have been too hot for you to get the engine to work that day.

Charley

My Feedback: (2)

Wasn't too hot. Eight in the morning, 78* F when I was running it. Here in the TX Hill country we stay in out of the sun in the summer afternoons! We retired folks, that is.

Just for an update, put the engine & fuel tank on the stand with the tank height set so that the centerline of the tank was even with the carb, ran it again. Still didn't run right, still had bubbles. I packed a bit of silicone grease around the HSN O-ring seal, reinstalled it. Engine ran better, no bubbles. Overall though, it acted like it had an air leak to the CC. Loosened the carb hold-down, pushed down hard on the carb, re-tightened the hold-down. Engine ran almost normally until it sucked up the silicone grease on the HSN & started leaking. So, found a new O-ring for the carb base (13mm ID, 1.5mm dia.), waiting for the HSN O-ring from NV; couldn't source it locally. Will run it again when the parts come in.

CR

hsukaria

I also found out that the needle jet assembly was loose. I tightened it against the carb body. I don't know why it worked itself loose, along with the needle valve o-ring being chewed up. But you might want to check the carb needle jet assembly and make \sure it is tightly secured.

the pope

oops pulled a clanger ! Getting my norvel powered plane ready for tomorrow and discovered there is a filter on my plane between the tank and carb after all . Sorry about that .Cheers

Charley

My Feedback: (2)

Yes, I found that I could loosen the jet tube a bit so as to rotate the fuel inlet nipple to the most convenient placement. That nipple fitting is sort of soft on the surface, has no gasket, seals OK when the tube is tightened up. NV offers a brass fitting also. I suppose it uses gaskets or some such.

I ran the engine yesterday morning after installing the new O-rings. It ran fine once I got the LSN set right.

CR

Charley

My Feedback: (2)

Found a 50mm stud at belmetric.com which is just the right length for my Escapade's spinner, an APC 11x6 & prop nut with a couple of threads left over. Part #S6X50E. They also had some long bolts which can be cut to necessary length for an extended prop stud.

Just for info,

CR