Irvine 46 MK4 Silencer leaking

[PDB]

I've minimal experience with glow engines so this might be obvious to some.

 

I was using an OS46AX2 which between the two halves of the silencer had a gasket and all the crud came out of the end of the silencer.

 

Following a crash the AX got some mud in it so is being stripped and now I've got a new Irvine 46 MK4 which is now run in. I've noticed a lot of the exhaust crud is coming out of the join between the two silencer parts. There is no gasket in there and I've tried nipping up the bolt that runs through it without much effect.

 

Would it be worth getting the surfaces machined true, could a gasket be available but I've not yet found one or is it something to put up with?

[steve too]

Granville Instant Gasket (or equivalent).

[J D 8]

A smear of epoxy also works.

[Keith Berriman]

Could you try a waps of PTFE tape don't forget to put some behind bolt heaf

[Don Fry]

Get a sheet of gasket paper, Flexoid is good brand, E bay., also a smear of silicone sealer, leave to dry for av couple of minutes to get a “skin” on it, and screw it up to  clamp. Leave to cure, screw tight. 
But just the paper will work.

[PatMc]

Breky cereal carton cardboard will do.

Once the leak is fixed you will probably want to lean the mix a little as the silencer pressure to the tank will have increased.

[PDB]

Thank you so much everyone, very much appreciated. 👍 I'll update with what method I end up using. 🙂

[Peter Jenkins]

Self amalgamating tape is also and option.  Plus, if you wrap the whole silencer with it it increases the silencing by reducing the tininess of the silencer i.e. damps out some of the high frequency noise.

[PDB]

Thanks again all, I had some self amalgamating tape spare and that has worked a treat.

 

[Nigel Heather]

Car shops (like Halfords) sell high-temperature silicone sealant.  Works well on exhaust manifolds, also on carbs.

[PDB]

Unfortunately the self amalgamating tape didn't last long, I ensured the surfaces were clean and stretched it 50% as per the instructions but after a couple of runs it slipped down the silencer.

 

Got a tube of Granville Instant Gasket, disassembled the silencer for a good clean before applying so see if that solves the issue. 👍

Edited May 31, 2023 by PDB

[David P Williams]

As others have said, a smear of 5 minute epoxy will do the trick. Separates easily when you need to.

[steve too]

3 hours ago, PDB said:

Got a tube of Granville Instant Gasket, disassembled the silencer for a good clean before applying so see if that solves the issue. 👍

 

I would advise applying the silicon, finger tightening, allowing it to cure for a few hours and then fully tightening.

 

Don't forget to do the ends of the machine screw.

[Peter Jenkins]

I used a couple of layers of self amalgamating tape and went well forward and aft of the join.  Might be worth trying that PDB.  

[PDB]

5 10 minute flights, so far so good.👍

[Martin Harris - Moderator]

One thing I’ve noticed is a tendency for people to tighten the lock nut without having fully tightened the screw first. The lock nut stops the screw from loosening further in the end cap but any slight movement between the two silencer halves will cause fretting and obvious leakage - look for black oily residue for confirmation. 

[steve too]

16 hours ago, PDB said:

so far so good.

 

I would be tempted to put a bit of hose on the outlet to try and stop crap ending up on the wing. IIRC the stuff that I use is car radiator hose from ebay.

[PDB]

5 minutes ago, steve too said:

 

I would be tempted to put a bit of hose on the outlet to try and stop crap ending up on the wing. IIRC the stuff that I use is car radiator hose from ebay.

The OS 46 previously used had a groove around the outlet into which you could secure a silicon pipe with a cable tie. The Irvine has no groove hence I've been unable to secure an extension onto the outlet, anything I have tried has come off.

[Nigel R]

You could put a small round head bolt right through the outlet to give the cable tie something to secure against.

 

Or try cleaning it up with IPA or whatever, and glue on a silicon tube with some sealant?

[steve too]

20 minutes ago, PDB said:

The Irvine has no groove hence I've been unable to secure an extension onto the outlet, anything I have tried has come off.

 

Interesting. There is no grove on this exhaust and the hose has been there for a while.

 

(This exhaust was sealed up with some black Loctite stuff...)