SMOKE SIGNALS

A friend has a Triumph 3TA that smokes mainly on the right hand cylinder. The longer he rides, the worse it gets. First thoughts were valve guides and/or rings so we had a look. On start-up, oil returns to the tank – but in a constant stream and not the intermittent bursts I normally expect from a Triumph. It carried on far longer than I thought it would to empty a crankcase full of oil.

We took off the filter cap (which had been put on with a chisel by the PO…) but there was no debris, despite the fact the gauze screen had a hole in it! The pressure relief valve was gungy but the piston seemed to move. Why is there so much oil being pumped back? Is there a problem with the pump pushing oil? Is there an issue with the oil being pushed into the sump rather than the crank?

Our next step is to take off the timing cover to look at the pump and crank feed. Then it’s ‘off with its head’ to inspect the valve guides; then the barrels come off to look at the rings, etc. Any other suggestions?

Malcolm Ross, member

Interesting. It’s usually the leftside cylinder which smokes. Check compression; then guides and rings. If the cause was the pump it would smoke from both sides of the engine. Frank W