Tiger Cub New Build Oil Leaks!

[matchlessman]

With a new motor and rings not yet bedded in you will get increased crankcase pressure, causing all sorts of oil leaks. I should review whats happening after its properly bedded in.

I always found that the standard breathing through the cam was fine. As its a timed breather the engine effectively is under a slight vacuum as the piston goes up, which helps to suck the oil back in. If there's a lot of oil in the crankcase, that could point to a scavenging issue, are all the oilways clear?

As far as the oil tank is concerned, don't fill above the return point or it will drain back into the engine and make it very smokey on start up. The oil level should be below the return, which enables you to see it is returning... and when its hot and has returned any from the crank case there's space for it..

You don't need vast quantities of oil in the tank, I ran mine with a Miller top tube tank and it was always cool enough. If you want more cooling, substitute the plastic pipes from the engine to the tank with copper microbore central heating pipe, with just 2" connector pieces at each end. Just change it more often as there isn't so much doing the work.

[brucey]

The Cub on its first practice trial at Canada Heights last week. It ran really well with the only problem being an oiled plug after a couple of hours. this needed replacing before it would run properly again.

In answer to your question, this is a standard Cub frame with modified tapered headstock bearings and various other minor bits done. I have seen Alan Whittons frames and they are very nice!

I have retained the original head angle but have been told the Montesa forks I'm using are a bit long and will affect the handling. I still think they are infinately better than the Heavyweight Cub forks I had on a previous bike!

I have also now fitted an external oil filter which adds about 1/2 lt oil capacity in addition to the 1lt of oil held in the top tube tank. This should help it run cooler!