Blog 175 Postscript 20th – 27th July 2011

This is just a quick postscript to our last blog.

We are still stuck in Mackay, my initial thought was just that the bike had got too hot and blown a head gasket. We rang Mario at Thunderbikes in Perth and got some replacement gaskets on their way.

Mario being the star he is got them on their way that afternoon on an overnight service so we waited to pull the bike apart until they got here (that was our second mistake our first running the bike on E10 unleaded petrol with added ethanol).

E10 is common here and is the standard unleaded fuel. 95 octane is regarded as super unleaded in most stations and is considerably more expensive.

We still hadn’t received the gaskets three days later, the courier company delivered them to the wrong place and weren’t exactly helpful about rectifying the situation. After many phonecalls we eventually got our hands on them and removed the head only to find that was damaged too. Ever feel like things are ganging up on you?

The bike had been making a weird almost rattly noise (not pinking) under heavy load for some time although it ran sweetly the rest of the time. This was partly why I changed the rings in New Zealand. I was convinced they were going to be in a load of bits when I took the barrels off.  As it turned out they were fine and although worn would have lasted a while longer. Then I blamed the camchain for the noise but pulling off the left hand head two days ago revealed what was really wrong.

The strange noise was detonation which is the fuel mixture exploding rather than burning. It is very destructive and in this case it had eroded away under the head gasket which is why it blew. It was pointless just to replace the gasket, it will only do the same thing again so I had to ring Mario once more and organise a secondhand cylinder head which should be here soon.

Follow the finger to spot the hole in the gasket. I pulled off the right head just to check and that was okay, partly I think as it has better airflow. The bike runs a lot hotter on E10.

There were some signs of mild detonation when I changed the rings in NZ but there was no damage to the head. The E10 was the final straw I think, it took me a while to realise but just recently the bike seemed gutless and noisy so I tried running a tankful of 95 octane and the difference was immediate. The noise under load all but stopped and it ran much better and cooler.

Unfortunately I realised a little too late but at least we know now to avoid E10 where ever possible.Talking to local bikers afterwards they all seem to avoid it like the plague. We also received an email from Karens parents (a little too late) saying that there were rumblings about Ethanol being introduced into unleaded petrol in the UK and the problems it might cause. Ethanol is just a cheap filler and the net result will be that everyone will have to pay more for 98 octane super unleaded..

At least it happened now and not in the middle of the desert somewhere remote, we have also taken steps to improve the airflow to the cylinders in preparation for when it gets hotter. To do this I moved the oil cooler over further and temporarily removed the rubber spray flaps on the side of the mudguards to improve airflow, along with adding airscoops to the front water jerry cans. I also got a plastic fan from a breakers yard and bolted it to the front pulley to pull air over the cylinders. I rigged this up in the UK but left it at home as the bike ran cool enough not to need it, we will see how it goes over the next leg. The fan cost $5 from a breakers yard so it’s not a big deal if it doesn’t work and we junk it.

We are still waiting for the replacement head and it has been extremely frustrating as we are on the edge of town and couldn’t get anywhere due to no public transport from the campsite.

Luckily we met and got chatting to a fellow camper Rhondda, she very kindly loaned us her XT225 (Serow in the UK) which has stopped us both going stir crazy and allowed me to nip out and get parts etc. It made such a difference and we are really grateful to her, we have also been invited over to their bus this evening for dinner as her husband Gary has finished his weeks shift in the mines. While we were in town we had a look around some of Mackays old art deco buildings and did a tour of the op shops looking for a glass photo frame or mirror to use to grind the gasket surfaces flat. We found one for 50 cents and a few other useful things as well. Unfortunately we also picked up a parking ticket for parking in the wrong place, we went and explained it was us not Rhondda and that we didn’t realise we were in the wrong place. We are really hoping they let us off because we really don’t need an $80 fine on top of the expense of being stuck in a $25 a night campsite for over a week.

The idea with the photo frame is that you stick a sheet of wet and dry paper to the glass which is flat and then rub the head and cylinder on it in a figure of eight motion to get it flat again. Because it’s only wet and dry it’s only removing thou and it was worth doing as it definitely improved it.  Here is a picture of me in mid grind and our temporary “garage”

Hopefully we will receive the head tomorrow and then we can be on our way again.

Just for a laugh have a look at this V8 barbeque we spotted for sale (and the price of it !)  V8 racing is really big over here.


  1. #1 by malc on July 28, 2011 - 1:21 pm

    Great stuff. fantastic photos,
    take care

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