Access to needle valve in enclosed cowl?

[Kelly]

 How do you access the needle valve without taking The cowl off on a fully cowled IC engine.

Cheers Guys

Kelvin

 

[Stephen Grigg]

Im in the same situation,Ive bought an extension and will make a hole for it to exit the cowling  when I  reach that stage,Im still building the model at the moment

[Former Member]

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[Russ]

I only use OS engines which have a hole in the end of the needle into which you can insert an OS needle extension or make one from piano wire. This is held in place with a crub screw which is located on the needle and loosened/tightened using an appropriate allen key. I do not know if other engine makes have this.

Hope this helps.

 Russ

[260 Flyer]

Or of course you could use an engine with a remote needle valve and mount it in a convenient place!

[Kelly]

Thanks guys.

Hi Russ Doh  wondered what the grub screw was for.

Cheers all.

[Guest]

the vibration on my 90 4 st caused work hardening on the extension which eventually broke. ( the hole in the cowl for the extension had to be big enough for the bent over bit and this gave it all the room it needed to vibrate.)

 I now use a tip picked up somewhere to put a piece of stiff neoprene ( or similar ) tubing over the needle long enough to reach the cowl - I then put a small hole in the cowl to match up and the tubing guides a screwdriver into the notch cut  ( dremel ) on the end of the needle

[inspector9566]

same as John above i found that using an extention wears the needle velve and the anti vibration spring after a while and the carb settings change in flight I now use the same method as John and no longer suffer

[Kelly]

I have been looking at some tips for the Saito, the method John and Colin have suggested is recommended for the Saito . I will go for this method.

Thanks to all

Kelvin 

[Guest]

Just to add to above, I used the neoprene tubing for my 0.5cc diesel albon dart , but extended the tubing outside the cowl and simply turn the tubing to adjust the needle - you can just about feel the clicks as it turns.

[Kelly]

Cheers John

[Simon Chaddock]

There is not much new, this is the original "flexible" needle valve extension on a 1950's Frog 500.

Easy to take outside the cowl if required and no vibration issues.

I must restore it & get it going one day.

[inspector9566]

Kelvin use the outer of a bic biro resined onto the needle velve to locate the screwdriver dont forget to cut a slot in the top first use a bit of wax across the top of the slot to stop the resin filling up the slot

[Kelly]

Thanks Simon and Colin

[Kelly]

I have used a mix of the methods suggested.

I cut a slot in the needle valve, a bit of heat  shrink  and hard  plastic tubing as found in a electrical connectors bits and bobs box from Aldi.

Photo of finished job

Tiny hole in the cowl.

Thanks again for the advice

Kelvin

[Myron Beaumont]

I have used an old wound brass/bronze guitar string as in the Frog 500 configuration above .  By the way -they were a b----r to start weren't they ?

[Former Member]

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