In Balance

There are few things more troubling than dealing with a drip...

What to do about that drip? Answers on a drip tray please.

❝Yes, we’ve all experienced the sinking feeling when we look under our motorcycle and see a patch of oil on the garage floor.❞

Of the many things this column could be about in this issue, the drip we’re dealing with here is an oil drip. Yes, we’ve all experienced the sinking feeling when we look under our motorcycle and see a patch of oil on the garage floor. It is a feeling I’ve experience recently with my Yamaha TY Mono.

The engine had to come apart after the kickstart shaft stop moved on the shaft. On the face of it, this doesn’t sound too bad, but once the stop moves, the spring pressure is gone and the kickstart flops around like a floppy thing with extra floppy added, and then it damages the case. The case is magnesium and, once damaged, it is not easy to repair and it is even harder to find a replacement at a reasonable cost.

So, the shaft is best repaired or if a new bit can be found, then it can be replaced. As it happened, Nigel Birkett knew the problem and, even better, he had a new, old stock shaft on the shelf. All I had to do was strip the engine, replace the shaft, reassemble the engine and fill it with oil.

Pulling the engine apart isn’t difficult, it’s a Japanese engine and things are made sensibly without a multitude of spacers and distance pieces that have to be in exactly the right place or gears won’t stay in, or the ignition won’t work or… well… lots of other things can happen.

As with most things taking an engine apart is easy but putting it back together so it seals and holds oil inside is the tricky part. Luckily, the world has moved on in terms of gasket goo and there are all sorts of anaerobic concoctions that will only set if all of the air is squeezed out. So, while it is still a good idea to make sure the case faces are flat and meet perfectly and use the goo as a belt and braces thing, the problems of the old days, when the goo would set and solidify and block oilways and breathers, are potentially gone. So, all things indicate a nicely sealed face that will keep oil inside the engine.

Of course, the engine isn’t the only area that can let go with an annoying drip, which itself can prove frustratingly difficult to trace at times, while other times such leakage source can be glaringly obvious.

I don’t know about other people, but my own personal experience of annoying drips and their source seems to swing between two extremes… if it is difficult to source then it will be in the workshop but on the other hand if the leak is glaringly obvious and massive, then I will be out in the middle of an event and thus unable to do anything about it.

Just such a scenario happened to me some years ago with a Can-am. The top tube of the frame is the oil tank and feeds oil into the engine via a tube and a pump. In the middle of an enduro my feet started slipping off the rests and when I eventually stopped to investigate, oil was pouring out of a crack in the frame. Unable to stop the flow but needing to ensure oil would lubricate the engine, I had little option but to convert to pre-mix on the spot by catching oil in the petrol cap and tipping it into the fuel tank.

This was not a precise modification, but it worked and the event was finished. Then, once home, the frame could be stripped out, the top tube flushed out and a welder instructed. This cured the problem and as far as we know the repair is still in place.

I do have a drip of oil under my own Can-am and the issue needs addressing, though I think it might be a simple issue with the oil tube from the tank outlet. At least I hope that’s what it is, as the bike now has a sidecar stuck on it thanks to a moment of weakness.

Other annoying drips can be from fork seals… I just cured my B40 and Bultaco of such drips, but the Bulto is causing grief with the primary case drain screw refusing to seal.

A bigger issue with the B40 engine is the puddle under the engine. This has been traced to a split sump bolt hole and will require a full strip in order to sort it – why has this not been done I hear you ask? Well, I don’t want every single bike I have all stripped out and in bits on the bench at one time, so the job will have to wait until the source of the oil leak on my Yamaha is cured.

The pool under it was frustrating until I took the bash plate off and realised a lot more oil had settled in the plate than I realised. A few days without the plate on showed a leak-free engine. Now to deal with the next annoying little drip...