Excellent post Tom! Tidy workmanship as well - kudos
A few questions for you:
1) On the inlet side patch, you took out some of the radius. Is this necessary?
>not entirely, but it did make it a lot easier to get at all the packing at the inlet end.
2) Does the tube come too close in proximity to the body to use a disc for cutting in these areas?
> Yes. I gang drilled the corners of the windows and cut between with a hacksaw blade. It wasn't that time consuming - it took much longer to get out the old packing.
3) What would you have done differently? Alternate locations perhaps?
>Probably stay the same. Windows are needed at both ends and on both sides to be able to get at all the packing.
4) Is there anything going on in there besides the tube?
>just the tube
5) How much time was on your silencer, and how solidified was the packing?
>not sure, the bike is new to me (2000 model). I suspect it had been split along the seams and re- packed previously because the welds don't look very 'factory'. The packing was oily, but this may well be because the timing and / or jetting is off and the bike doesn't run as crisply as it should.
6) What shape was the tube in and is it captured in the same manner as the rear silencer?
>The tube is in good condition. I think it is the same as other silencer, but not 100% sure because I couldn't see much inside
7) Have you noticed a performance change at all?
>don't know yet. The chassis is still in pieces in a box waiting for me to put it back together !
I took some photos to show how I went about cleaning and repacking
I cut the windows here:
and here
I used the drill (with depth gauge) and hacksaw instead of cutting disk to cut the windows, to avoid damaging the perforated tube inside. A hook was made from stiff wire to pull out all the old packing. Once the packing was removed, I heated the inside of the perforated tube with the gas burner. The oily gunge caught fire and was left to burn out. It was then easy enough to shake the soot out and get everything reasonably clean.
It was then repacked, taking care to get packing into all the corners:
Then a paper template was used to get the right shape for the plates to go over the windows. Silicone and pop rivet:
Good to know it worked on the 348 - my 315 is similarly noisy as it is. What function does the middle box perform ? Is it just an additional silencer, or does it manipulate the exhaust pressure waves a bit like an expansion pipe on an 2t enduro or motocrosser, to give the desired engine characteristics ?
When I cut windows into the 315 middle box, will I just find a perforated tube and packing, or are there other parts in there ?
This has been discussed on this forum before. You may want to search for it.
Cut it open, re-pack it with Silent Sport packing and weld it up. I have had it done several times by Mike Komer at the Tryals Shop. This method yields excellent results. I have seen it done by the factory boys as well, when they were on two strokes.
Mike used to grind the seams and split in half, but the last one he did, he cut a window open on top and bottom to access the packing.
These other methods sound dangerous and I don't believe that they will be as good as new packing.
Hi, I can't find anything about the 'window' method with the search facility. It sounds like a better option than cutting the seams because it avoids any potential misalignment problems, but does anyone have any info. about best placement of the window ? Judging from the weight of the component, I'm guessing it might be complex inside and I want to avoid unnecessarily damaging anything when I open it up. Would a pop riveted and silicone sealed piece of aluminium over the windows be viable repair, with future cleaning and repacking in mind, or does it need to be welded ? Is Silent Sport packing different from the normal stuff ? Not heard of it before. TIA for any advice, Tom.
Best way to decoke middle box on a 315r
in Montesa
Posted