NC24 Exhaust Collector Box MacGyver Fix. Possible?

[FrisianVFR]

Hi everyone,

So for the past 2 days I've been working on my good old NC24 and fixed most of its problems in the process. One major issue is a rotten exhaust, a problem I've had for more than a year now. I've tried to find an intact 2nd hand collector box for months, without any success. I've tried wreckers in the Netherlands, Germany and Belgium, and Ebay UK as well but I can't find anything. Money is tight as I'm a university student, so buying an aftermarket stainless steel version isn't possible. I'd love to have one I just can't afford it simple as that. I don't want to get rid of the bike either but the sound is becoming more and more unbearable. I've tried to fix it several times but it hasn't worked, I mostly used Gun Gum and similar products.

Schematic drawing: http://i.imgur.com/EDMAYzV.jpg (too large to show here). The problem lies at the part of the collector box (CB), shown in red, where the two front downpipes (FWD DP) enter the CB. The FWD DP themselves appear to be intact. It's hard to get a good look but there seems to be no exhaust left for about 0,5-1,0 cm at the part where the FWD DP physically enter the CB. Normally they should be connected to and enter into the CB through a vertical plate recessed a few cm into the CB itself. I hope that the drawing helps, really difficult to put it into words.

And now on to the actual MacGyvering part!

Anyway, I think I have an idea (and several variations) on how to fix it but I'm not quite sure whether it'll work. One version of the idea was to use a high temp silicone kit used on things like stoves to physically close the gap, it also seems to be a much more robust solution than Gun Gum. Do you think that it'll fix the problem? I've looked for several different brands and products, and most seem to be able to handle up to 300 °C.

Since I live in NL my first choice is http://www.bison.nl/static/products/ass ... 3522_2.pdf this (source in Dutch). I wonder whether or not it can handle the heat and chemistry of the exhaust gasses, because I obviously don't want to create a potential fire hazard. It should be somewhat flexible and is silicone based so it shouldn't crack or rot like Gun Gum does. It's also sold in most hardware stores in NL.

I've also thought about first using Gun Gum again (or a similar product), wait till it's hardened and then apply the silicone kit. Just to create a better gas seal and minimize contact between exhaust gas and the silicone kit. Maybe throw in some exhaust tape in there as well?

Anyway, is this a safe option? I'm getting more and more bothered by the noise (I tend to avoid town centers like the plague now), and want to actually enjoy my bike again... Thank you for your time and hopefully opinion.

TL;DR: MY COLLECTOR BOX'S GOT MORE HOLES THAN A GOLF COURSE! WILL ADDING SILICONE TITS GET MY GIRL'S HOLES TIGHT AGAIN?

[Morespeedvicar]

Hi, I have used high temp glass fibre on car exhausts before, but not tried it on a bike. Can you borrow a welder from somebody and scavenge some bit of car exhaust an make one? May not be pretty but be better than gumgum.

[lutha23]

Go for second hand exhaust system it should be cheaper and affordable

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[willandrip]

You are better off going to see a fabricator and asking him if he can cut and shut new metal into the old rotten collector.
It will cost more than silicone or glass but will work and if done correctly will last longer than the remaining original box.It might not be pretty...that depends on the man's skills.

Firegum/exhaust repair tape/silicon/glass is a get out of jail temp fix to either pass a roadworthy test or stop noise until a new exhaust arrives. Non are permanent or durable...if they were why would manufactures still use steel.

Sorry to state...exhaust repairs that come in a tube/bottle/jar or tub rarely work.

[Neosophist]

vibrations from the engine tend to destroy any gungum type paste pretty quick.

replacement is the only real viable option as you have to take the engine out to the get thing off.

there are a few good second hand ones about if you look in the right place

if not there are some aftermaket stainless steel ones that have slip on rear headers which make removal a non engien out job

expensive to replace