Need some help please

[rcnut]

Sunday took my 600N Nitro Pro out to finish the engine break-in. Motor is the O.S. 50 hyper with SB pipe, 30% wildcat, no governor (at this time), plus a header tank. Flight times have been around 7-8 minutes, for the main tank...header still full.

On the fifth flight, put the 600n into an inverted hover and the head speed started to increase. Had about just over 1/4 tank of fuel and a full header tank when this happened.

Not being to happy with this new RPM, I flipped the heli over and the motor went lean. I quickly landed, by hitting the throttle hold and autoing down. About half way down the motor quit.

The motor was real hot. Opened the main needle 1/4 turn out (from 2-1/4 turns out), and checked the glow plug (was ok). Restarted the motor, it fired up fine and set it on the ground and spun up the main blades just prior to hover. My thinking was to use the fuel to cool down the motor. I let the motor run for a couple of minutes like this while dropping the head speed gradually. Then hit throttle cut to stop the motor, checked the temp, and it was cool.

I know, most of you are going to freak out over my main needle setting. My buddy's heli is the same way. I am using Arrow trend tubing, all fresh and new. No Align filters, header tank is mounted with one of the lower bearing block screws. Muffler pressure line is free and unobstructed. Prior to installing the pressure nipple, I checked the hole to make sure there was no flashing that could cause a restriction in muffler pressure.

So what caused the motor to lean out in inverted flight?
Should I use a governor??


Thanks for the help!

PS. helped my buddy get his 600n into the air yesterday as well. I was truly a great day to fly....with 2 600n's!

[invertmast]

make sure your clunks are both moving very freely

[mporlier]

This realy sounds like air getting in somewhere. is your carburator well seated, the O ring should be invisible?

[Finless]

Also make sure you clunk line has not split at the nipple connection or come off all together and is flopping around in the tank!

Bob

[mccrind]

....no align filters...but you do have a filter on the heli,right?

[LJS]

Hi Nut,

If you don't get it with the easy stuff, I'd take the engine out, and flush out the carb. This would mean taking out the needle and the barrel of the carb and flushing it out. It sounds like there may be some garbage in the fuel inlet. You should be close to 1 to 1 1/4 turns out for normal running.

Keep 'em flying.:YeaBaby:
LJS

[brgsstm]

I would also check your head bolts are tight.

[fultonr]

I was told to chuck out the supplied fuel tubing inside the tank by the LHS. Put something else decent in there.

[nwolsink]

My bet is on the clunk line, I had the exact same thing and my clunkline was so bad that when inverted it would "collapse" instead of bend.

[BarracudaHockey]

2 1/4 turns out on a hyper should be blubbering rich, you're getting air or something else is going on somewhere. You should be close to 1.5 turns give or take a few clicks for fuel type and density altitude

[rcnut]

Last night I was checking the fuel lines and found the plastic nipple that goes into the main tank leaks air. I clamped the fuel line coming from the muffler and pumped air into the header tank with a 2 oz syringe. I heard air coming out of this area, so I placed the syringe after the header tank. And sure enough, air is leaking from the plastic part going into the main tank. It's not bad sitting upright, but inverted, the clunk will shift to the top of the tank causing the air leak, or reduce the tank pressure.

Something I also want to check, and soon! Sunday I took out my Raptor 90 and on the second flight, the motor quit. I landed, then filled the tank and tried to start it, but the motor wouldn't turn over. So I dropped the motor out and tried to turn it over by hand only to find the motor was locked up. I went to remove the head and found the screws were loose!

Once I removed the head, the story became clear. The head loosed up and the motor went lean. The piston cracked and embedded part of the piston into the head. I could see the exhaust path on the head where it was leaking. So no I need a new piston, ring, and sleeve, about $110.00 in parts.

So what do I do to fix the plastic part on my 600n??

[rcnut]

Tuesday night I was checking the fuel lines and found the plastic nipple that goes into the main tank leaks air around the rubber ring. I clamped the fuel line coming from the muffler and pumped air into the header tank with a 2 oz syringe. I heard air coming out of this area, so I placed the syringe after the header tank. And sure enough, air is leaking from the plastic part going into the main tank. It's not bad sitting upright, but inverted, the clunk will shift to the top of the tank causing the air leak, or reduce the tank pressure.

Something I also want to check, and soon! Sunday I took out my Raptor 90 and on the second flight, the motor quit. I landed, then filled the tank and tried to start it, but the motor wouldn't turn over. So I dropped the motor out and tried to turn it over by hand only to find the motor was locked up. I went to remove the head and found the screws were loose!

Once I removed the head, the story became clear. The head loosed up and the motor went lean. The piston cracked and embedded part of the piston into the head. I could see the exhaust path on the head where it was leaking. So now I need a new piston, ring, and sleeve, about $110.00 in parts.

So what do I do to fix the plastic part on my 600n??

[stevehonn]

With the relative cost of a new tank versus the repairs to your engine after a lean run, I'd fit a new tank and test it before fitting.

[rcnut]

Rebuild the motor in the Raptor 90, and rechecked everything on the 600n. Charged both helis, then went flying.

I richened the OS 90 SZH and it started much easier, it even ran better blubbering rich then when it was new. Put 3 flights on it and all is good.

Then switched to the 600n, which flew better than the Raptor, IMO. Main needle setting 2-1/2 out, and runs like a top! Still has a little RPM increase when inverted, but doesn't lean out like before. Need to pull the motor and check head bolts, verify there tight. Then order a new fuel tank to see if that will help.

However, I do have one question. When measuring the lenght of tubing inside the tank (with the clunk attached), which corner do you measure to? The corner closest to the right side (needle valve side), the middle of the tank, or the corner on the left side (muffler side)?

Thanks for all your help, will keep you posted as to what I find.

[forjer]

Got an update? I've got the same thing happening. I was wondering if you fixed / replaced the leaky tank and if that made a difference.

I'm getting maybe 7 minutes till bone dry on my hyper (in a Raptor) using a carbsmart set to 90 C and head temps reaching 95 C on my eagle tree. Good power...good smoke. Needle is at 2-1/4 turns out.

I'm also getting a dark fuel leakage on the front landing skid around the head area.

[rcnut]

Sorry for the late reply, work has changed my hours to 2nd shift (3:30 pm to 1:30 am). I haven't been near a computer until now.

I did order a new tank from HP, but haven't installed it just yet. I was rebuilding my X-Cell SE, so the 600n is next. However, I may have an answer for you.

When I started this thread, I blew up my O.S. 91 SZH in my Raptor. Upon inspection, I discovered the head was loose. And thinking back, I too was having a lot of black oily stuff around the front landing gear as well.

Hopefully I will find some time to investigate this problem, possibly this weekend.