Hitchcocks Forum

Hello All

I’m having difficulty sealing the chaincase on my ‘93 Bullet. The o-rings I have are quite hard so I’m going to experiment with softer compounds. Does anyone know the cross section diameter of the standard o-ring? I’m guessing 1/4 inch but could do with knowing before ordering!

Thanks

Stephen

Just before you do that inspect the inner face of the outer cover. Some of them are machined very badly. If it's rough, dress it down with abrasive paper stuck to a board. Also, check the leak isn't from the clutch shaft seal at the back. The standard o ring is usually ok for the job.

Check it's flat too. It's tempting to overtighten the central nut and they can land up with a deformed outer cover. Hold it against a piece of glass to get an idea of flatness.

Thanks Pete & Stink for your replies. The leak is definitely the o-ring and the outer cover is definitely flat. I fitted an o-ring that I’d had for a while and had trouble getting it to bed into the groove evenly as it seemed very hard. Maybe I’ll just buy a new new one!

Well, they cost less than a fiver so definately worth a go.