Charley

My Feedback: (2)

Fired my GX up today. The HS needle is sure sensitive. If it's back out more than 1 turn the engine floods. Not sure about the LS needle setting. At 1/2 throttle opening the LS needle is well away from the idle bar. I think it's backed out so far that the engine is running on the HS needle only. Didn't run it very long. I'll run it some more in the morning.

CR

Edit: Searched the thread for the LS needle setting. Found post #790 that said the factory setting was for the LS needle to be about 1mm from the idle bar at WOT. Will set it there and open the HS up to 2 turns, see how it runs.

hsukaria

Cafeen,
The premixed gas that Earlwb mentions in his post is pure gas and oil, no ethanol. However, it is quite expensive, IMO.

CafeenMan

That's not what I'm asking about though. There's a station where I can get ethanol free. I'm wondering if that will store for long periods.

hsukaria

Beats me!!!! It depends what you will use it for, I suppose. If you will use it for cleaning or thinning epoxy like I do, then I don't think you have to worry about storing it for long periods. I don't think anybody here willfully burns ethanol for combustion in engines though.

If you are asking about ethanol-free gas, then I don't know. I suspect it would still have those volatile additives that degrade over time.

CafeenMan

Yes, I'm asking about ethanol free gas.

Charley

My Feedback: (2)

How about you guys get back to talking about the engine.

CR

CafeenMan

The engine is still being discussed.

burmanf

Hi The Pope
I have been running the engine for about an hour and it still stops when I fully open the throttle and lean it out a bit.Do you think this is normal or there could be another problem? I am using Klotz benol 14% and premium petrol.How long did yours take to run in?/////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////

the pope

Hi there Burfman ! I had a fair bit of grief early on with mine . It kept blowing head shims , the later versions came with an extra one . Once I added the extra one all my probs went away . If you have the head removal tool ( or u could make one ) you could have a peak . Also as I have mentioned before I had a ****e load of swarf internally . Maybe you may have a bit of crud in the carb or the needles may need adjusting , maybe open up the lo-speed a wee bit and see what happens . Sounds like you need to get your head around how the carb works . I run mine richer than you would normally other wise it just cuts out like u mentioned .Just be happy with a engine that doesnt cut out on the groundas it tends to run smoother in the air . The hi-speed needle is mega sensitive and some have used the glow one with good results . It should be run in by now me thinks . Cheers the pope

Charley

My Feedback: (2)

OK, I'm going to confess. After running my engine the first day at less than 1 turn open, I decided to lean the LS needle and try it at the recommneded 2-1/2 turns open. Tried it with the starter, it pumped raw fuel through & out the muffler. After that wouldn't run with the starter battery removed. Compression seemed low. Took off the back plate & found the rod was bent. My fault; I should have flipped it through before applying the starter.

Took it all apart, nothing else visually broken. Talked to "Dmitri" at NV CS. Poijnted out to him the instruction were wrong. He says no. However he's sending me a new rod, some gaskets and some wrist pin keepers. I paid $15 through Paypal. I figure they're trying to meet me halfway.

More later,

CR

CafeenMan

Hi Charley,

Your post is confusing me. Are you talking about two different needles? You said "less than 1 turn open" and then say "lean it... 2-1/2 turns open". So how do you lean from less than one turn to 2-1/2 turns? I'm assuming you're talking about the HS needle being less than 1 turn and the LS being 2-1/2 turns?

You really have the HS less than 1 turn open?

What voltage starter battery are you using? Is it a regular motorcycle type battery or something larger?

I've hand turned mine probably a couple thousand times now. I watch movies on my computer and just had the engine sitting on my desk so any time I was watching a movie I'd pick it up every once and while and sit here turning it over. It's plenty oily - keeps dripping it out of the carb and muffler. Before I even think about putting a starter to it I'll take out the plug and turn it over with the starter with a rag on top of the engine to blow a lot of the oil out. When I try to actually start the engine I'll prime it and hand start it first at least until it kicks over a few times to make sure it blows out all the excess oil that's still in it.

CafeenMan

Pope - do they make a fine thread needle for this engine? If this is a fine thread needle then do they make a finer thread needle?

the pope

Hi there c-man , from what Ive read ( I dont have this needle ) folks have been using the needle from the glow version . Having said that I dont think its necessary to have one but I would have got one if I knew about it at the time of purchase . I think this info would have come from somewhere in this thread . Maybe someone could chime in with their 1st hand experience with the use of this needle . Cheers the pope

Charley

My Feedback: (2)

What voltage starter battery are you using? Is it a regular motorcycle type battery or something larger?

I've hand turned mine probably a couple thousand times now. I watch movies on my computer and just had the engine sitting on my desk so any time I was watching a movie I'd pick it up every once and while and sit here turning it over. It's plenty oily - keeps dripping it out of the carb and muffler. Before I even think about putting a starter to it I'll take out the plug and turn it over with the starter with a rag on top of the engine to blow a lot of the oil out. When I try to actually start the engine I'll prime it and hand start it first at least until it kicks over a few times to make sure it blows out all the excess oil that's still in it.[/QUOTE]

Sounds like a plan.

CR

CafeenMan

Thanks. What kind of 12v battery are you using? The reason I ask is that when I used smaller 12 volt batteries they usually struggled to turn over a flooded engine. I doubt I could have broken a connecting rod in a .40 with a 5 of 7 Ah battery.

Charley

My Feedback: (2)

I use a "Jump Starter." It can put out 700 Amps for a short time if needed. I also use it to recharge LiPo batts for my electrics at the field. The con rod in the GX looks to be a casting, has a cylindrical cross-section. It bent in the middle. In a hydraulic lock something has to give. IN 35+ yrs I had never broken an engine before. Grrrrr.

CR

whiskey29

Hi Guys...

Any tips on priming before starting ?

To this day, I can't tell if I primed too much.

I had to prime a bit, flip couple times, then block the exhaust and give it a starter until it almost running, then start using the starter.
What do you guys think about the needle ? I still think its a little sensitive, one click could drop 200-300 rpm.

earlwb

Well, if the engine is flooded, you need to drain out the excess fluid before you try using a electric starter on it. Any engine could be damaged if the piston comes up towards top dead center and the excess fluid causes a hydraulic lock. With a two stroke you can lower the piston by rotating the prop and tilt the engine and or plane over to drain out the excess. Then rotate the prop and flip it a few times to ensure it would get locked up. Then you can use the electric starter on it. But if you use the starter to clear a flooded engine, you risk bending or breaking the rod, the crankpin failing and shearing off, or the piston breaking or in a coupld of cases the cylinder/head breaking off.

earlwb

I do not remember needing to do anything. I use the electric starter, get the engine to run, then wait a while warming up the engine before I remove the glow plug ignitor, then work the engine to full throttle and get it warmed up good. Then go flying. I'll have to try hand flipping it more, but I haven't bothered with hand flipping the engine much.

Charley

My Feedback: (2)

Got my GX .40 reassembled with the new rod installed. It still has pretty good pinch at TDC. It's back on the engine stand; will run it again today with the recently acquired APC 11x6 prop. Have to wait until after 0900 so as not to PO the neighbors.

CR

Charley

My Feedback: (2)

Started running the GX .40 on the stand starting about 10:00 this morning. Had to squirt fuel directly into the carb in order to get it to start. Ran about a half (8oz) tank through it after adjusting the needles. The HS needle wound up about 7/8 turn open, the LS needle is ~1.6mm from the spray bar. The recommended settings aren't even in the ball park,

After a cool down period, refilled the tank, had to prime it again to get it started. Got tired of priming so found that if I held a finger over the muffler outlet, momentarily, while applying the starter, it would self-prime & start. Ran another 2 tanks through it. Getting ~10.2K RPM with the APC 11x6; not bad for a .40 at 1700 ft AGL.

Guess I'll put the Escapade together and fly the engine. More later.

CR

hllywdb

C-man, the needle for the nitro 40 that has the extension on it works great. It's not the thread that is finer, but taper on the needle. The standard one works fine for most props/conditions. The extended nitro one just gives a little finer adjustment.

As to electric starters and flooded engines, I've seen people bend rods and break cranks on 60's. I usually pull the plug. I've got a few pattern birds with inverted engines so it happens.

Charley

My Feedback: (2)

This stuff is supposed to be good for both glow & gas. I plumbed the tank for my test stand with it around 1 Oct. I used that tank to break in my GX .40 on the test stand. I had planned to use that tper Tygon as a replacement.ank in the Escapade after break-in.

I took the tank off the test stand yesterday, I found that the Sta Flex tubing in the tank had hardened so much that the clunks were immobile! One could lose an airplane over that. Oddly enough, the Sta Flex I used to connect the tank to the filter & carb stayed flexible likewise the connection to the muffler. I suppose the stuff doesn't like being immersed in gas.

Tower is sending me some Super Tygon as a replacement. Now I'm looking for Viton or Hayes Neoprene.

CR

burmanf

Hi Pope
.Dmitri told me to run the engine rich as you do.I flew it like that and it did not cut out and although it wasn't giving maximum power it still had more than the OS 40 FSR that was in the plane before.I had 2 flights, each about 10 minutes, which used about 4 oz. of fuel.

Charley

My Feedback: (2)

The interesting thing about how Dmitri behaves is that he's helpful as far as advice & parts are considered but obdurate when one tells him that the instructions need revising.

CR