OS70 tuning problem

[Helitubbie]

Hi all

Im having a problem getting my OS70 to run right. it has been fine untill recently.
When i throttle up it has a habit of dying, normally when the engine is already warm.
I have disconnected the governor, gone back to factory settings and tuned from there.
Just when i manage to get it running sweet (plenty of power and smoke)
i fly around a little then bring it in to land and check the temperature on the back plate this is also fine.
Then throttle up and it dies again. AAARRRRGGGGHHH!!!
I have tried so many different settings you would not beleive!
Yesterday i must have walked about 5 miles with my model to and from the pits!
I must be missing something somewhere
Anyone help PLEASE

[Bender]

check yer fuel lines first.
I had a os 61 give me fits tuneing and after I dismantled the carb I ffound a piece had worn so it moved around altering the tune, this was a old 7h carb tho, what carb is the 70 fitted with?
while your fiddling, take the exhaust off and have a butchers at the piston, it may have had a lean run and partial seizure, only problem with governors, they can hide a bad tune as you likely know

[Helitubbie]

The carb model im not entirely sure of but its a new (ish) with three needles.
i have changed the clunk line recently.
i suppose i should take the carb off and make sure there is no sh1t in there.
the other day when i was trying to sort it i got a bit heavy handed with the antenna on me tx and broke it, so i wont be trying again till me new one arrives!
Hopefully i can sort this soon!

thanks

[Raptorite]

Hi Helitubbie,

I had a similar problem with an older OS 91 SXH a while ago. In that case I took the fuel nipple that the line from the tank goes onto off and found there was debris in behind it which would partially block off the fuel to the main needle from time to time.

Those three needle carbs are normally pretty reliable, so my guess would be some sort of debris in one of the lines somewhere, is the problem in this case.

Good luck with tracking it down.

Cheers,

Pete.