Saturday 16 November 2013

A bit of a catch up

Yes it’s been a long time since I updated the blog but a heck of a lot has been going on in my life, so hopefully you will excuse me dear reader!

Last time you may recall I had just done a training day in the Cotswolds and got some great photos from my friend Ann. I had also recently finished the Ryedale Rally, where It looked like I might have got 11th place in class. The good news was that I eventually wound up 8th in class, my best ever result, I knew I had been riding fast but didn’t realise just how fast!

Racing was forgotten for a while and I enjoyed a couple of days out with Ann. As she was waiting for an operation on her dislocated shoulder and wanted to get in as many miles on the bike as she could beforehand as she would be spending several weeks unable to ride afterwards.

In early August we rode up to the Peak District on the day of the protest by the TRF/GLASS against byway closures by the Peak District National Park. A cold, damp ride from Towcester saw us arriving rather late so we bypassed the event at the National Park centre headed straight for the cafĂ© in Hope for coffee and cake (anyone notice a trend here)?

Afterwards we did some green lanes near Sheffield.

Ann on Houndskirk Moor

A Choice of KTM Adventures, little and large!
Then we rode up to the top of the  Long Causeway on Stanage Edge, where the weather started to deteriorate rapidly:

I don't think Ann was enjoying the weather!

Heading for home we stopped at a T-Junction but as I pulled away something was clearly wrong and the bike was almost uncontrollable. I pulled up to find the rear tyre had punctured....

It's only flat at the bottom!
It was still raining and wouldn't be too long before it started to get dark, so I was reluctant to try and repair it, especially as I only had some very short tyre levers, fine for changing a skinny 120/100 on the CCM but I wasn't sure they'd be any good on the meaty 150/70 on the back of the KTM (I struggle with a set of 14" tyre levers in the warmth of the garage)!
So after wobbling along the road to the thankfully close pub, I called the RAC and they said a patrol would be with me in an hour. So we retreated to the pub and ordered dinner! In the event the Patrol driver called me and asked if it was a tubeless tyre as he could plug it, of course it is a tubed tyre, so no joy! As a result he ordered up a recovery truck straight away, which saved some time.
So after a very pleasant dinner, I got to head back to Stevenage in a truck, whilst Ann had to ride home to Towcester in the dark and the rain.... and yes I do still feel guilty about that (something I'm sure I'll get reminded about for a long time yet)!

A week later we met up again for a much more pleasant ride to Didcot to Premier Bikes, where Ann wanted to take a look at a Husqvarna TE 449 for sale. After that we headed down to Stonehenge but first stopped off at the Costa Coffee at Solstice Service on the A303 for the obligatory Cake and Coffee!

The A303 was at a standstill so we bypassed it to the north through Larkhill Camp (and past the curious Woodhenge) and then down the byway to Stonehenge. On arrival the byway was being used by literally hundreds of cars avoiding the charges at the car park, although it manage to snatch a photo of the stones...

We soon retreated across the A303 and further down the byway for some peace and quiet:

A bit quieter here!

Anne starts to have new ideas about what bike to get (good job I removed the keys)

Needless to say, the ride home was "interrupted" at Starbucks at Oxford Services!

Next I had the CCM to rebuild, the next event was the three day Centennial Rally in Carlisle, so I knew I had to cure the now very serious oil leak before that and sorting the backfire was a priority too.

However in sorting the first I found a (temporary) cure for the second! After degreasing the bike thoroughly, I took it out for a spin on the road to try and detect where the oil was leaking from. At first the bike just didn’t want to run until I realised I had forgotten to replace the air filter after removing it for cleaning. “Not a problem” I thought and put the choke on to balance up the mixture. This had the almost magical effect of eliminating the backfire. A bit of playing around with the choke settings and it became clear that the bike was running too lean in the mid-range so a solution looked possible.

It was soon evident that the cause of the oil leak was the cylinder base gasket, a big job but not impossible, so I ordered up some parts and set to pulling the bike apart.

Now it is the perceived wisdom that you can’t remove the cylinder head on the 604 engine whilst it is in the frame, let alone the cylinder itself but I knew differently. Getting the engine in and out of the frame is a truly horrible job as at the factory they used a jig to spread the frame to get them in, so without one it simply doesn’t fit into the frame without a monumental struggle! So I was looking to avoid this if at all possible.

By removing the two front engine mounting bolts, you can rotate the engine forward and down in the frame and this gives you just enough space to remove the cylinder head…. So far, so good.

By removing various bits from the frame (coil, ignition unit and the wiring loom) I hoped to be able to lift the cylinder off as well. It was an extremely tight fit but I eventually managed it.

The reason for the oil leak was immediately obvious!

I think that base gasket has seen better days!
A new base gasket in place, I spent a considerable amount of time (and skinned knuckles) trying to get the cylinder back over the very long retaining studs. This at first seemed impossible but working on the principle that if it came off in situ, it must go back again, I persevered and eventually got it back in place. Then the next challenge began, getting the piston back inside the cylinder!


This involves compressing the piston rings into the liner… easier said than done. Having struggled to do this on other engine rebuilds in the past, I knew the easy solution was to get the right tool for the job; a piston ring compressor. Unfortunately I found it impossible to find one larger than 75mm diameter; unfortunately the bore on the CCM is 97mm. So I admitted defeat and attempted to install it by hand. Over the course of several days I struggled with the damn thing and whilst I could get the first two (compression) rings into the bottom of the barrel, the third, oil scraper ring just wouldn’t go. It is a complicated bit of engineering containing a spring and having two “scraping” edges that are very sharp, the ends of my fingertips suffered a bit during this process.

Doesn't look much but they did sting a bit!

Eventually I managed to snap the oil ring, so had a couple of days rest whilst I ordered a new one from CCM, at the princely cost of £38 + VAT!!!

Whilst waiting for this to arrive, I decided to smarten up the bike and fitted new tank graphics and number backgrounds; going for a black, grey and white combo as opposed to the old black, grey and yellow. I also tidied up the wiring loom and fitted a new chain and sprockets, front brake pads and tyres. Other jobs involved replacing the cable tie holding the speedo on, with a more permanent solution and sorting the non-functioning neutral light. That turned out to be easy as the bulb holder had simply fallen out the back!”

When the new oil ring turned up, a few more days or struggling, cursing and split finger tips ensued. Eventually the ring “slid” into place but with a horrible “snapping” sound, that sounded suspiciously like the noise the old ring made when it broke. However the barrel slid on OK and the engine turned over smoothly with no worrying noises, so reluctant to go through everything again and rapidly running out of time, I continued with the rebuild.

New O rings for the head (the Rotax doesn’t have a head gasket), a new cam belt and spark plug were all installed and the rest of the rebuild went OK.

I altered the position of the carb needle to make the mixture richer in the mid-range and took care to seal the exhausts into the head properly, all in the interests of eliminating the backfire.

Eventually finished, the bike fired up easily and seemed to make no strange noises, so all looked good. A brief road test and…. No backfire, no oil leaks result!

 So all was ready for heading off to Carlisle…. To be continued!