EME 120 twin problems

[Peter Smedley]

Standard exhausts.

[Tony Collins 1073]

Have you checked for any restriction, everything has to be ruled out.

[Peter Smedley]

Come tomorrow I will check. Thanks

[Tony Collins 1073]

Hi Glenn. Yes I forgot about the old reed fart. I always made sure there was a real good one on my Weslake 342 engines.

Fart.jpg (21.05 KiB) Viewed 10460 times

[Peter Smedley]

Morning
The exhaust are just empty tubes, so no reason to look any deeper.
Lapped the reed cage very lightly. There is a film of fuel sealing all around the edges
Turned over the engine slowly, no ppphhhrrrttt from the reeds

On taking the carb cover off to check the metering lever height, I don't recall that the grove in the diaphragm button was slid under the fork end of the metering lever

metering lever jpeg.jpg (47.13 KiB) Viewed 10444 times

[Tony Collins 1073]

Hi Pete. I have to repeat that any carb fault will show up on both cylinders not just one. Stop looking for something
that is ruled out by logic.
As far as the reeds are concerned, You must hold the block up to a light and any poor seating will show a light coming through. Check that the lift pressure for both sides feels the same. When checking for the reed noise when turning over
the engine the carb throttle must be open otherwise you may not hear it. The noise is caused by the reeds vibrating as they
try to open and then the reed strength causes them to close again. This is a bit like a reed driven musical instrument
which relies on suction at various levels to cause the vibrating reed to create a sound.
Therefore, no sound from reeds means insufficient suck at that oscillating sped.
I am not familiar with this particular engine but it would seem that reeds are operated through the crankcase together.
This would imply that one cylinder is not sucking as hard on the compression stroke as the other.
Please recheck your cylinder compressions again, separately with one plug removed each time and swing the prop.
You should be able to feel any difference.
After that Pete I am out of ideas.

Good luck.

PS. This would also rule out the faulty reed block theory.

[Glenn Masters]

I've just gone back to the beginning of the thread and an obvious question springs to mind about the fuel / oil quality and ratio may have a bearing . . . ? Is it running on top quality synthetic oil at 50:1 ratio ? I use sthil ultra oil at 50:1 for all my engines, even my Moki radial engine . . . its a cleaner burn, especially noticeable when idling for a prolonged period . . . . What are you currently using ?

[Peter Smedley]

Tony and other you’ve been very helpful, thanks.

32:1 oil ratio, with high grade Castrol 2t. I’ve used it since I’ve started running gas engines. I get my fuel from the local Texaco garage and not the supermarket

Started it up this afternoon. The problem has disappeared! I don’t know the fault which is annoying but it has now gone and the engine is starting and idling well. It’s not haphazardly dripping fuel so that’s good. Super strong slow idle

Crossed fingers and pray it doesn’t return. Thanks again

***Sorry now correct name ***

[Tony Collins 1073]

Pete, every effect has a cause.....fact.

[Glenn Masters]

Tonya . . . that must be you Tony ! . . . and I must be therefore *other*. ah well, glad its running ok again now.

[Peter Smedley]

FYI, changed prop from 26x12 to 28x10 and gave it another run. Starts easily, nice idle and after some needle fine tuning picks up well. Stock settings was 1 1/4 out from closed on high and low, ended up 1 1/4 high and 1 1/2 low.

Thanks again

[Tony Collins 1073]

So the big question is What Changed??????????

[Peter Smedley]

I relapped the reed cage a couple of days ago

[paul hughes]

So it was the Reed block and it looks like that 'other' bloke diagnosed the problem. Well done GLENN.
It made me smile and reminded me of the photo of the 'other beech' ( in joke)

[Glenn Masters]

Ha Ha . . . The other Beech was indeed a classic ! Cheers