screech2964

I have a Hyper 50 on a thunder tiger V2 and it seems to lean out after about 4 min. in the air. I have ran it so rich on take off it loads up and will still lean out. Have checked muffler and it is not loose and have replaced all fuel lines and clunck line in tank. Also I can land after a few min. and it will load up at about 1/4 throttle so bad it will kill the motor b-4 I can get it airborn. 1st time poster. Thanks

john josey

I take it you have checked the pressure nipple on the exhaust is not blocked ?

BarracudaHockey

My Feedback: (11)

My first stop for that is always the clunk line. If you replaced it then I would pull the tanks and loop a peice of fuel line between the outlets and put them in a bucket of water to see if you get bubbles. Maybe the rubber stopper is bad.

Also check your head bolts, make sure the carb is fully seated, and that there's no plastic flashing inside the header tank where the outlet goes to the main tank.

john josey

My sceadu was quite bad for this even from new.I think the poor cooling shroud has a lot to do with this, much better with the shroud where the cylinder head is fully enclosed. I got that fed up i fitted a perry pump.

We should maybe also say here that using a fuel with low (ish) nitro content can aggravate the problem. (fuel cooling)

screech2964

Yes John i did make sure the nipple was not stopped up on muffler, But you did say somthing that rang a bell about the the low nitro amount in fuel. I use a 15% nitro which I know a lot of people like a 30%. Have been useing 15% for a long time but you may be right about it compounding the prob.



Barracudda I did notice when checking the fuel lines in tank that the line in the main tank was accordian style. It seemed really flexable I will change it out.


Thanks guys for the advise

Gavin2407

Hi Screech

IMO I believe you are running to lean on the high end and to rich on low end. At a 1/4 throttle you are still on low end, only about 1/2 throttle does the high end take effect. The low end is only a ratio of the high end and by having a lean high end, it causes you to compensate by making the low end very rich just to get it running. What does the back plate feel like after you land? It should just be warm. Regarding the fuel issue, we're running TT 53's, OS 50 H's and OS 55's, all using 15% nitro fuel with no problems. Have you got a filter between the tank and carb? If yes, remove it and test again. Are you running a header tank? If yes, bypass it and test again. Header tanks are beneficial but not if installed incorrectly, "output" line nipple should be lined up with the centre of the carb. You said you replaced all the fuel lines, but did you use the correct line. Nitro fuel line is not the same as "gas" fuel line. The ID of the line is also important because this could also be causing a fuel restriction leading the engine leaning out.

Regards,
Gavin

john josey

How far open is your main needle using the 15% nitro fuel ?

BarracudaHockey

My Feedback: (11)

That doesn't really matter.

Needle settings are effected by a lot of factors, nobody elses needle setting is right for another unless they are identical models, fuel, muffler, and location.

john josey

I agree to a point, but if his needle is 1/4 turn open or 3 turns open, something like that, it may point to soething else. From my experience the hyper 50 with 10-15% nitro is about 1- 1-1/4. Although as you quite rightly say theres a few factors that will determine the actual setting.

screech2964

Wow Guys what a great sorce of info. All the trial and error I'v tryed prob. could have been avoided if I would of checked here first. Thanks for all the help will check all suggestions and see if I can get it worked out. Thanks

john josey

Yeah, no problem. It`s just two experienced heli pilots thinking out loud.

Let us know how you get on.

cheers
john

screech2964

Ok Guys, bypassed header tank, new glow plug, tinkered with the high and low needles. The only way I could get it to get past 1/4 to1/2 stick throttle was to have it so lean the head speed made me want to run...lol. Do ya'll think it could be a motor bearing going bad. I flew it about 6 months ago with this same set up b-4 I put it up for the summer. IT did have a little bogg in it at the same stick but was not so bad that i could'nt pass by it. Now I cant get the darn thing off the ground. Am i missing somthing or do I need to tear in to the hyper 50 and replace the bearings. What do ya think? Also it did seem to rev up(lean out) at about 4 to 5 min into the last few flights it made. I put my finger on the back plate and it was vary hot but not untouchable.

john josey

I`m sorry but i have to ask this....is your throttle linkage to the radio mechanicaly correct ? if your not sure what i mean, if you can post the ATV value`s of the throttle channel, i can tell you from there.

cheers
john

screech2964

Yes john I have not messed with the radio or the mechanical linkage since it was set up by Michael Prewitt of Raptor Techniques a year or so ago. I do believe it is still correct. I just keep thinking a motor or carb. problem since I probably have 50 to 60 flights on it just like it sits. Seems like this bogg has slowly gotten worse over time. And never be sorry about asking me the simplest question because I am still really new to helios. I flew planes till I seen a helio flown 3d and I was hooked.

john josey

OK, if it was me i would take the carb off and strip it down and clean it out with meths or clean fuel, or if your not keen on doing that you can take the main needle right out and attach your fuel pump to the carb to pump fuel through the main jet.

When you try it again, low end at factory setting and main neddle at one and a quarter turns open. That should be close enough to know if your getting somewhere.

screech2964

That will be my next move then John
Thanks Scott.

john josey

No problem scott, let us know how you get on and we`ll take it from there.

BarracudaHockey

My Feedback: (11)

If Mike set it up you can be assured the linkages are perfect.

Flying Geezer

My Feedback: (14)

Most usually, when an engine runs too lean no matter the needle setting, it's drawing excessive air. This is especially true when it starts and idles OK and goes lean on throttle up. You can adjust a needle valve for a proper idle, and sometimes mid throttle by setting it very rich even though it has an air leak. As the engine continues to create a stronger vacuum with advancing throttle the air draw increases.

I would check the carb to be sure that it is properly seated and sealed by the "O" ring. I would check the backplate, and the gasket there. And, as BH suggested earlier, the head bolts.

All fuel lines including the clunk lines should be REPLACED, not just checked.

Most of the time when an engine is leaning out on throttle up, it is not getting less fuel, it's getting more air.

Hope this helps.

screech2964

Thanks Flying G, You bring up very good points I will Check all suggestions.