Hi,

Something i noticed the other day while washing my CBR after picking it up was the silencers had some slight movment so i removed them and found the link pipes were fairly loose where they fit into the collector box.

It seems from what i can make out that in the past rather than the gasket being replaced when is was worn out, the collector box has mikalor clamps which have been overtightened in the past trying to get the link pipes to seal properly and have distorted the holes. There were remains of old gasket in there, but not much!

Here's some pics:








The downpipes are stainless, possibly delkavic, motad or suchlike although on pictures of new stainless systems i have looked at the holes in the collector box where the link pipes fit in have 4 slots to enable the clamp to tighten correctly around the gasket - i presume these aftermarket downpipes have to have gaskets fitted for the link pipes as i have heard this is the case for the original honda exhaust system?

Although mine don't appear to have the 4 slots. I have seen on oem systems that they have two slots with threads welded on with a bolt through to tighten up around the gasket.
Mine seem to have these 2 slots but are closed right up as well as the rest of the hole mis-shaped but it looks like it may have originally had the tighten threads welded on but these have been removed

I think these are the gaskets i need to replace.
Exhaust Joint Gasket Seal Honda CBR1000 F 87-99 | eBay

Would it be best to cut slots in my collecter box holes to enable the clamp to tighten properly around the gasket when i order and fit them - also what would be the best way if any to straighten out where the metal is distorted so they resemble something resonably round so the new gaskets will fit in properly? I don't really want to have to buy new downpipes if i can help it - just to be able to unbodge whats happened in the past and get the link pipes sealing properly without having to resort to using exhaust paste / silicone.

Cheers

 

For what it's worth I used Yale Muffler Paste instead of gaskets as the necks of my collector box were "iffy"

The equivalent in the UK would be something like Bosal Muffler Paste

Seals tight and hard for me with no leak issues after 3 seasons

 

Thanks for the advice Sprock, i have ordered new gaskets & got new mikalor clamps. I'll try and cut some slots in the collector box necks & straighten them out a bit. I'll be trying some of that paste if i cannot get a good seal.

The last time i tried exhaust paste ages ago it didn't last long at all - but then i think it was just cheap stuff.

 

yeah now come to think of that , stock collector box tubes have slots cut in them.

Yeah the heat activated fibrous exhaust past is tough stuff. Seals up well for me and
no degradation after 2 years on two different Hurricanes I put new ViperRaceCans on

 

Got it sorted now, cut four slots in each of the collecter box necks (after making them round(ish) again!) with a draper / dremel type tool - should have really got some diamond / metal cutting discs, i used the standard cutting discs that came in the kit and went through about 4-5 of them, after a short while of cutting the discs just shattered! it took a while but got there in the end.

Would have been easier with a angle grinder, but would have had to have removed the frontpipes as there ain't much room with the collecter box being so close to the shock linkage.
Had to remove the rear wheel as it was!

Managed to get a decent seal with just new clamps and gaskets so at the moment no need for exhaust paste but will bear it in mind for the future.