Irvine 53 carb setting

[Winco Steve]

Hi guys,

Does anyone know the initial secondary needle setting for the Irvine black jetstream carb? Trying my hardest to guess but advice is better! The screw is fully home so adjustment turns out would be the ticket. Failing all else...anyone got a spare carb laying in a box unloved?

Thanks,

Winco Steve

[Winco Steve]

Just to add.....engine is the Irvine 53 Red body, Black carb.

Winco Steve

[Keith Berriman]

Hi Winco if I remember some time ago my secondary needle was flush with thetop of the  tube it was in or maybe just a turn in

Edited By RC Plane Flyer on 27/03/2013 19:04:04

[Ian Jones]

Fortunately I keep all my instructions neatly filed away so that on an occasion such as this I can easily refer to them..... I wonder where the file is!

Opps cross posted.

Edited By Ian Jones on 27/03/2013 19:34:17

[stu knowles]

Twin needle carbs

Set the main jet for max rpm and the adjust a 'tad' richer, say 1/8th turn.

Let the engine idle. Open the throttle, if it coughs & splutters as it picks up speed. - too rich. If it just dies, too lean. Screwing the idle needle in = leaner, out is richer. This will get you to the right ball park.

Fine adjustment, - let the engne idle and then pinch the fuel line just as it goes into the carb between finger and thumb to cut off the fuel supply. If the engine slowly speeds up and gains significant revs before slowing down. - too rich, adjust the low speed needle by 1/4 turn each time. If the idle rpms just slow down when the fuel is cut off, - too lean. Adjust the low speed needle 1/4 turn richer and retry until the rpms rise by a modest amount and then slowly die. This is about right  Go past the 'right setting' just to prove that the system works and you are getting the expected results. Then go back and find the exact right setting refining the adjustment to 1/8th turn

 

Repeat the whole process from setting the main jet to double check and the engine should idle reliably and open up cleanly. Once main and idle needles are set just fuel and fly. Don't be a needle twiddler every flight. If you find that the engine becomes unreliable, clean the carb and supply line and start again.

Perhaps I should have started by saying that make sure that the carb is thoroughly clean and back flushed before begining. Use clean and filtered fuel. Make sure any inline filters are also clean. Without getting into a fuel discussion , -Use  a quality fuel with 5 or 10 percent nitro. If hard up, use straight fuel but good quality. I only use synthetic oils. Other may have a different view but this is mine and I've come to rely on it. In time you will make up your own mind but it is worth trying a good branded fuel as described and checking if there's  a difference  with lesser fuels.

Have a try and let us know how you get on

stu k

Edited By stu knowles on 27/03/2013 20:25:25

Edited By stu knowles on 27/03/2013 20:31:30

Edited By stu knowles on 27/03/2013 20:32:18

[Bearair]

If you have done all the above, and are still having problems with the low speed adjustment from one flight to the next. Its worth checking that the low speed adjustment needle is not moving with vibration in flight. I have had a couple of 53 where this has been the problem.

[Winco Steve]

Hi all,

Thanks for all the good advice. I will start with screw about midway and then follow the very comprehensive instructions supplied by Stu.

cheers,

Winco Steve

[Andy Green]

You could always send me the carb to set it up for you.

See this today.

Andy

[Winco Steve]

Hi,

I was a bit baffled re the last post? Have now read the thread and confirm.....not guilty!

I find myself, for once, at a loss for words! Made me smile anyhow!

Winco Steve

[Steve Hargreaves - Moderator]

If setting it from scratch the following may help....

First put a length of fuel tube onto the fuel inlet so you can blow through it. Open the main needle 2 turns or so (not critical) Put a pin into the intake & close the barrel until it traps the pin....then gently screw the idle needle in until it seats......now, try blowing though the fuel tube...you should turn a nice red as you can't blow through it....!! Slowly open the idle needle until you can just hear a gentle hiss of air through the carb...your face should now be a sweaty lemon colour....

Take the pin out & try starting the engine with the main needle at 2-2.5 turns or so & it should run.....It will need tuning but shouldn’t be far off….

HTHs

[Winco Steve]

Hi,

Thanks for the information, much appreciated. Off to the work bench with first aid kit, breathing apparatus and a lung full of air!

Regards,

Winco Steve

[D for Donald]

Does anyone know where I can get hold of the manual/pamphlet for an Irvine 53 Mark 1? I've had no luck so far.

Paul

[Flyoz]

It never ceases to amaze that few IF any people actually answer the question asked.

Rule of thumb start settings ( if totally messed up) try NOT to fiddle with the low end set the high end first and see how it transitions etc first

Low end needle 2.5 turns out ( car engines typically have the low end screw flat, flush with in its barrel)

High end 2.5 turns out ( how people claim 5, 6or even 7 turns is amazing)

To tune open throttle 1/4 and start --- see how it goes for a few seconds Only

if too lean turn out high needle in 1/16-1/8th inch increments.

Set Low idle to obtain a reliable idle do this by turning the needle (rich or lean ) in 1/16th inch increments ie turn let it run for a few seconds turn again and run a few seconds till its right. A tacho helps actually see what revs are doing (experts who claim they can do it by ear are fooling themselves and everyone else0.

When you feel the engine is right see how it transitions from Low to high

when you push the throttle up sort of brisk- if it gurgles and chokes its a bit rich on the low end.

When you set the highest revs with the high needle, richen the high needle till revs drop about 300-500 rpm(an engine always leans out by itself in the air.

[Don Fry]

Posted by D for Donald on 29/03/2013 21:15:18:

Does anyone know where I can get hold of the manual/pamphlet for an Irvine 53 Mark 1? I've had no luck so far.

Paul

I have all the paperwork for one. It was made in about 1999, is this a Mk 1, the engine was red, black carb barrel

Don Fry, Donalds of the world unite, except one in the good ole US of A.

[Peter Christy]

Steve H's method is as good as any for setting up an unknown carb. It will get you pretty close to the desired setting without too much subsequent fiddling!

That was how I was taught to set up a carb by an acknowledged expert years ago, and it works!

--

Pete

[Bob Cotsford]

After 4 years I suspect that the OP has either sorted his motor out or gone electric!

[Peter Christy]

I should've gone to Specsavers........!

--

Pete

[Nightflyer]

Some good advice given on setting up the carb in Flyoz post and very true so many people tinker without knowing what they are doing. I think the one other aspect is that if the engine still does not run right with the above that you need to start looking for leaks.

Most engines (inc. carbs) use neoprene rings as seals round the primary and secondary needles and also sealing carb body to crankcase, etc. What people forget is that these degrade over time in storage or from use and storage having been subjected to model fuels, oils and their waste deposits.

First sign of unreliable running or problems starting and setting up what has been a reliable engine - aside from the usual checks of fuel or dirt usually is resolved by checking or changing one or more O Rings.

[D for Donald]

Crikey, ​ I confess I had forgotten about my post of March 2013! Thanks all for your comments but I have sorted out the tuning on my Irvine 53 by using the tube and pin method. My request for the Manual was for completeness as I bought a couple of 53's on ebay back in 2013 and they are still going strong . The Mark 1 is a brilliant engine I have to say.