Westfield Megabusa Build Diary

15 Mar 2008
Scavenge pump belt problem, and engine trouble - really worried!

When running the engine, we get a squeak coming from the scavenge pump. The belt rides WAY to close to the front of the pulley and I think that's what causes it.

I spoke to Mark at the factory on Friday and he suggested reversing the pulley because it's slightly offset. I tired spacing it first, but it prevents the bearing from spinning.

The problem is that there is a plate which screws into the front of the pulley, but the thread that the screws fit into are only on one side of the pulley. We decided to remove the pulley, drill the holes through, and then tap them through to the other side which would mean the pulley could be reverse and the plate could be fitted to the other side.

Also, Dan had spotted a petrol leak. It was coming from the tank outlet to the fuel pump, but it was leaking from a section that we had nothing to do with. There is a boss that connects into the bottom of the tank which is pre-installed at the factory, and it's leaking. I pinched it up with a spanner and I hope it stops the leak. We had to pop out to modify the pulley, so we'll check the leak later.

The pulley took ages took ages as I had to travel elsewhere to use a vice, then drill bits would break etc. Eventually we managed to do it though, and once we fitted it back onto the scavenge pump, the belt sat further back. It's still very close to the edge, but a post on the Westfield forum confirmed that they all seem to be very close to the edge.


We fired up the engine and the squeak had gone which was good. The fuel leak is still there though, so I'll have to call Westfield and see what they think about it - it's very very minor though, so not unsafe in any way.

We decided to get some drive through the wheels and see if it works. We can also listen out for any rubbing or knocking etc.

I put the clutch down, and we hear a horrible grinding sound. I lift the clutch up and it does it again. That does not sound healthy. I tried it again and exactly the same thing happens. We cut the engine and then got a little worried. I can't think what's wrong!

I left the car for the evening, but I really couldn't relax. I had something to eat, and then still felt really unhappy about it, so I called my friend Ronnie who is a motorbike expert. He has rebuilt his R1 engine, and runs a T28 turbo on it. He has done the entire build himself, along with all the fabrication. He has done similar modifications for friends too.

He didn't like the sound of it at all. He said that everything on a bike is lightweight and aluminium, and so very soft. The moment you hear some grinding you're normally in for some bad news. He said he could come and take a look at it Sunday though, and in my mind there was no one better to have on the case, so I felt a lot better about it. I'm still nervous though.