help please
 

HI
I have not long built a hirobo Sceadu
Its had 36 flights with it and everything is a ok
Except its killing exhausts

The stock one that came with the kit kept coming apart at the center
Tried everything to stop it
So the shop that I bought it from advised me to try a tuned pipe so they supplied
A Zimmerman that fell apart at a joint after 4 flights and the supplier said it has been cooked
But supplied another one

So I fitted it and a cooling shroud and the shop set up the helli in order not to have the same happen again
It was great for 6 flights and fell apart at the same joint

Sceadu 30 size
Ervine 39
Running on prosynth and running slightly rich
Head speed 1600
Does not appear to have any vibration
Or high frequency vibration fuel is running clear
Engine / fan / and clutch assembly is all in balance

Could this be caused by the clutch spindle having any run off
And if so what tolerance is acceptable ?

Much appreciate any help
Thanks
Geoff

help please
 

My suggestion is to get a Hattori that is designed for a 50 and try that.

I have a Hattori and it is great!

If you still have the original Hirobo muffler you can get it to work. First disassemble it. Clean the bolt and back side.

Mix up some JB Weld and use it to seal the 2 halves. Reassemble using RED locktight on the bolt that goes through the center. Lastly use a self locking nut on the last bolt end. Has worked great for all I know that have used it.

Clutch shaft runout is normally .002 MAX try to get it less if you can. I had to open up the holes a tad to get it so I could narrow mine down.

help please
 

Yours is not the 1st Zimmermann that has fallen to bits.
This appears to be a re-occuring problem that has been discussed multiple times in another Forum.
If I understand this correctly then it is the pipe itself that fell apart.
If so then I would say that this is a clear manufacturing fault.
Cut your losses and put on a 2 piece Hatory muffler and use the support bracket that comes with them.
Expensive but end of problem.
Unless you can get the original one repaired as suggested by Furyicon

help please
 

Thanks for your replies
I think its best just to try another manufacturer
just trying to make sure the isn't a underlying problem

thanks
Geoff

help please
 

hheck

Thanks for your reply
I would be most grateful if you could let me know the address
of that other forum concerning Zimmerman pipes

Geoff

help please
 

Hi again, Geoff. Didn't realize you were a DarkSider (heli enthusiast) too...<G>

I believe he's referring to RunRyder: www.runryder.com

Steve

help please
 

Yes Steve
It was RR that I was referring to