evo 30 with OS 32 sx

[mingming]

my OS 32 sx engine cannot run on evo 30, any idea why?

here is my config
Main blade: from my old shuttle zxx (Semi symmetric; 550mm wood)
Engine: OS 32 sx still very good conditions (also from my old shuttle)
Muffler: original hibrobo black muffler ( from shuttle Zxx, Since it was designed to install on the right hand side of the shuttle, when install on the left hand side of the Sceadu, the silicon tube inlet has to be upside down)
Fuel: 15% nitro cool power
Pitch: mid stick 5 degree , high stick 8.5 degree
throttle: 0, 30, 53, 63, 100

Symptom:
RPM increases from low to mid stick normally. The blades start spinning.
Then drops gradually(seems overloaded from the engine sound) when moving up to higher stick.
but when return to mid stick the RPM increases again and then cut off.

any idea why? how to solve this?
is it the muffler problem becoz of upside down the silicon tube inlet so the exceeded fuel blocked the tube?

thanks in advance

[SteveL]

You could be ending up with a Vaper lock in the fuel line from spent fuel gathering in the bottom of the loop.
Your symptoms almost sound like to motor is too rich though. Have you tried adjusting the mixture?
I would go righer first (safer for the engine) and if it gets worse try to lean it out.

[mingming]

You could be ending up with a Vaper lock in the fuel line from spent fuel gathering in the bottom of the loop.
Your symptoms almost sound like to motor is too rich though. Have you tried adjusting the mixture?
I would go righer first (safer for the engine) and if it gets worse try to lean it out.

1.5 turns which i used on my old shuttle.
do you think OS 37 can help?

[Tomas Ahl]

The 37 delivers more grunt for you but the helicopter should fly fine with the 32 too.

[Ivan]

I woudl recommend getting a tapped hole in teh top of the muffler, and putting a screw in the botom where the muffler pressure was. Spent oil and combustion leftovers are not good for mixing with fuel.

You didn't say how much pitch you have on the top end. I woudl suggest that an OS 32 with 550's may pull 9-10º of pitch, if it is hot and humid, maybe not even that.

Also check your throttle setup to make dopuble sure the throttle is opening fully.

[SteveL]

A 37 will have more power like already mentioned but it will not fix the problem. I flew my EVO on a 32 for quite a while with no problems.

[mingming]

A 37 will have more power like already mentioned but it will not fix the problem. I flew my EVO on a 32 for quite a while with no problems.

what muffler did you use?

[Tomas Ahl]

Didn't there come a muffler with your EVO kit mingming? Both mine did (EVO 50:s, one ARF and one kit).

[mingming]

Didn't there come a muffler with your EVO kit mingming? Both mine did (EVO 50:s, one ARF and one kit).

the kit that i bought is muffler and blades less
some of my friends told me to change muscle pipe
any comment?

[SteveL]

I used an old Hatori I had from My shuttle days. It must have been set up for both L/R mount but I can't remember for sure.

[rob_jones]

My EVO flew fine with an OS 32. Not a lot of reserve power, but it did ok. One thing that confuses me is that you say the muffler was made for a Shuttle and to go on the right hand side of the heli. The Sceadu and Shuttle both have the engine oriented the same way (muffler on the left). Are you sure you have the correct muffler?

Your problem sound like a tuning problem. Open the main needle valve 2.5 turns and turn it in 3 clicks at a time until it gets better. If it doesn't get better by the time the needle is only 1.5 turns open, something else is wrong. Either fuel delivery or even bad fuel.

[SteveL]

Ok I feel better now. I was thinking to myself that I must have changed the muffler and just not remebered it. My 32 ran @ just over 1 with 15% and ~1 3/8 with 30%

Have you found the source of the problem yet?