Fitting exhuast tube to Century

[whigum]

Hello, I have an exhaust tube (and complete leg etc) from Silver Century that I am fitting to a Century 100, because I want the clutch and extra long shaft. I am finding the exhaust tube is reluctant to fit onto the head - should I carefully persuade it with a mallet, or should I cut out slits, like the original exhaust has, to help it fit over? Thanks

[headdownarseup]

Any pics of the offending items?

Jon

[whigum]

Afraid not, parts are abroad my boat, and I am currently not. I spent Saturday afternoon having a relaxed tinker in the sun

Things I did check for were buildup inside the exhaust tube, and around the head fitting. Pretty clear. The exhaust that was on there originally is brass and has (I think) four slits, which appear original - I'm guessing those allow the tube to fit on and be crimped tightly when fitted? The Silver Century tube does not have these. Maybe some heat to expand the tube? Or a rubber mallet?

[headdownarseup]

Depending on what motor your brass exhaust tube was originally fitted to, it might be possible to persuade it to fit with a rubber mallet.

The 4 slits i've generally found to be on the older 102's which have a cast exhaust clamp and pinch bolt fitting.
The century clamps i've generally found to be more of a stainless strap arrangement. Sometimes at the exhaust outlet of the cylinder there's a rubber 'o' ring which helps to seal the tube. Has your engine got this? It might just need a wiggle past the 'o' ring to fit. (a little smear of grease helps too)
Either way it's normally a fairly snug fit on there. Some gentle persuasion might be what's needed with this, but go careful with it as it's easily damaged and dented if your exhaust tube is made from aluminium.

Hope this helps

Jon

[whigum]

No rubber O ring on the exhaust outlet. It's definitely a Century 100 otherwise, I guess the exhaust tube was replaced at some point. I was quite pleased to discover it was brass, it's coated in multiple layers of silver paint, so I had no idea. It's in nice un-dented condition too - will hang on to it for later. I do like polished brass. The circular part of the exhaust outlet is possibly a bit bloated with rust, it's not rusty, but is far from smooth. I think heat and a rubber mallet may be the cure for this, and maybe a good scrub with an abrasive/wire wheel around the outlet also. I will certainly be careful, as the Silver Century exhaust is in great condition, don't want to damage it. Thanks for your input Jon.

[headdownarseup]

Yep, a good going over with a wire brush should sort out most of the problems. Might even help to allow things to slip into place a bit easier too.

For what it's worth i think the brass exhaust tubes end up being a fair bit quieter than the aluminium types as the metal is denser and absorbs a lot of the noise compared to the ally ones. Nice when they're polished up too

Jon

[whigum]

That's interesting regarding the denser metal being quieter. Will have to experiment sometime.

On closer inspection of the brass tube that came with the engine - it's chrome plated brass. Would that have come with a Century 100 originally? Or still sounding like a 102? And under some crud I may discovered the reason for the exhaust tube being too tight, there is some fracturing where the clamp tightens, looks like some rusty expansion on the exhaust outlet caused it - I will tape a plastic bag over the head to stop any bits getting in places, and give the the outlet a good going over with a wire brush/wheel.. I reckon that might allow it to slide on agreeably

Oh yes ,and here is a photo of the cracking I found on the tube.