Triumphrat

yakoo11 · 12-26-2009, 07:31 PM

On the front of the cylinder head there are 2 reed valves

One of the cheap tubes has developed a crack in it. Triumph doesn't sell just the tubes and I can't really find a replacement for it.

What does this system so, and is there a bypass for it? Does it rob me of any power if I disconnect it? Can I simply plug it?

yakoo11 · 12-26-2009, 07:32 PM

It's # 23

BombFactory · 12-26-2009, 10:42 PM

That is the secondary air injection system; it's an emissions system that injects extra clean oxygen into the exhaust to help burn off any excess fuel. It doesn't affect engine performance either way.

You can replace the cracked tube with vacuum hose from an auto parts store. You can also remove the system, but to do this properly you will need to build block-off plates that bolt to the head in place of the valves, using silicone for a gasket. You may be able to get away with using a rubber vacuum plug over the air inlet of the valve, but a block-off plate is more permanent.

The easiest thing is to use vacuum hose and vacuum hose connectors from an auto parts store to repair the system; plus, it's better for the environment to retain the system.

Will · 12-27-2009, 08:51 PM

Ah. It's California emissions. I don't remember ever seeing it on either TT600 I owned, even when taking the one I blew up completely apart.

ncdave · 12-28-2009, 10:43 AM

I'm not familiar with the Triumphs, but reed valves aren't just a Cali thing on other brands. I suspect Triumph is the same, but don't know for sure. You should be able to cut the hose and plug both sides of it without any ill effects. it's a pretty typical change on most other bikes. Generally it has to be done on twins if you put an aftermarket exhaust and intake on it because you get popping on decel. I'm not so well versed on i-4's though, so it may be different for those.