Sunday 22 April 2012

The search for the missing bearing

After my premature exit from the Rallymoto Sprint, I had to attempt to find out what went wrong with my CCM 604.

It felt like fuel starvation so first step was to strip down the carb. I thought I had solved it when I discovered a bit of grit lodged in the pilot jet but that didn't help and it was no better when I put it back together and on the bike.

So next likely culprit was electrics, I have an almost complete spare engine so swapped the stator and ignition pick up over but no joy. Next culprits were the ignition amplifier or the rectifier (both a regular failure on CCMs) but this would require borrowing the items off a friends bike to check them out and that wasn't posible for a couple of weeks.

So I decided to check some other things in the meantime:

First the cam belt, so after removing the cover the tensioner looked like it could do with a bit of tightening but nothing major.

Next, has it jumped a tooth? I could have marked the pinions and corresponding reference points on the back plate, turned it over twice and see if they still line up but decided instead to do it the way the manual says with a straight edge at TDC.

So I turned the engine over to what I thought was TDC and decided to remove the tappet covers to check.... glad I did!

There was about 8mm of play on the exhaust valve rocker

It turns out the roller/cam follower has self destructed!

And if you're still wondering what's wrong, here it is compared to the one out of my spare engine

So the exhaust valves were opening just enough to start the engine but obviously not enough to run.

So the question is what was between the roller and the pin? You can't see on the intact rocker, I was inclined to think a needle/roller bearing. which of course meant the rollers must still be in the engine ?

So do I have a poke inside the head, drain the oil and remove the sump plate and hope I find the offending bits, bung the intact rocker from my other engine in the head and hope for the best or do I strip it down and have a good flush out of everywhere.

Anyone who has ever tried to remove a Rotax motor (or replace it) from a CCM frame will know it's an absolute bitch. It took me two and a half hours to get the motor back in the frame last time I tried.

I decided to start with the first and see what I find!

So a few days later I had a fruitful "quest for the missing bits" in the sump of the CCM

First off I drained the oil, that turned up a few bits...

Then I removed the sump plate and found a few more bits in the strainer...

I then removed the smaller sump plug below the strainer, the one with the magnetic tip....

So that's where all the rest of it got to!

All looking good so far, next job is to flush the engine through from the rocker box to dislodge anything left behind.

Saturday 21 April 2012

Well what a month it's been!

So busy I haven't got round to updating my blog, but yesterday I went down with a nasty dose of Man Flu, so whilst sitting here feeling sorry for myself I thought i'd crack on...

Last blog you may recall dear reader I was getting ready for the RallyMoto Sprint Rally and so lets pick up the story there. Well actually let's not as the week before I had been at an Adventure Bike Rider Rally.

Now this was the other type of rally that many bikers will be familiar with where you turn up, camp in a field, get p*ssed and talk bikes and b*llocks and usually go on a ride out or two.

It was entitled the Chilterns Chill Out Rally and that pretty much summed it up. OK I will confess I wimped out on the camping as I trailered the CCM to the campsite near Ivinghoe, the original plan had been to ride there as it's only half an hour away from home but try as I might I couldn't get all my gear on the back of the CCM. And in anycase I had agreed to lend my tent to my friend Michael, so I slept in the Land Rover and the "Chill Out" bit was very apt it was rather cold, especially as I only took a two season sleeping bag on the basis that the forecast was for warm sunny weather with temperatures in the twenties, well yes they were but not at night!!!

I had volunteered to lead a trail bike ride on the Saturday which somehow got entitled the "Extreme Team". Now if anyone knows the lanes in this part of the world, they will know they are anything but extreme!

Nevertheless we set off in a group of eight and great fun was had by all. Only one incident of a bike "having a lie down" was noted which considering it was John on his second ever green lane trip and the first on his BMW R1150GS and he was actually stationary at the time (the old "i'll put my foot down only to find you have stopped next to a rut and the ground is a foot lower than anticipated" scenario)

So lets get back to other sort of Rally, the racing sort!

Although it wasn't until the Sunday, I had Friday afternoon off work so decided to head for Wales. Rather than camp at the very bleak Sweet Lamb Rally Complex I headed for the Campsite 15 miles down the road at Rhayader where I had stayed last August. A short walk to to the pub for a huge meal and a couple of pints and I headed back to the campsite and had a very confy and warm night as I'd brought my 4 season sleeping bag this time.

On Saturday morning I headed up to Sweet Lamb and helped out a bit with the setting up. Gradually more and more regulars turned up and we all headed into Llanidloes for a meal.

Sunday dawned frosty but with the prospect of a bright sunny day ahead of us.

The race format was a bit different with a short liaison stage of about 3-4 miles to get you warmed up and then a timed special stage of about 12 miles, the course being a figure of eight so you started both at the arena. We were to do eight laps in total however only your fastest lap counted so you could afford the odd bad lap.

First was the obligatory "sighting lap" where you are not timed, I was pleased to discover that I knew about 95% of the course from the Big Bike Rally Training and last year's Hafren Rally. Although some of it was in the reverse direction which proved a bit strange.

Lap One proper went well, I started the special and remembering the first couple of bends were tricky, I took it easy only to nearly ride into the back of Dave, who had started 30 seconds ahead of me as he exited the ditch on the inside of bend two, he clearly hadn't taken it easy!

Unfortunately this meant I was stuck in his dust cloud so had to throttle back as I couldn't see a thing.

The race continued with my time on lap two dropping a bit, although I had made the mistake at first of forgetting to switch on the fuel tap, luckily I ground to a halt on the untimed liaison section rather than in the special but this prompted a "modification" to the bike...

Then it was lap three although this didn't start well when I ran onto reserve on the liaison. luckily I was able to go and grab some fuel before starting the special but it did put me out of sequence in the running order. This lap then got much better and I felt like I was really getting into the groove, I was hitting bends in a gear higher than previous laps and remembering which corners you could attack without backing off, then it all went wrong....

The bike suddenly died on me and despite restarting wouldn't run properly at all, I limped round the circuit at no more than 10mph until it gave up the ghost. Luckily I got a tow in from Michael who was prepared to sacrifice one lap. Luckily we had a lunch break after that lap so I was hopeful I could get it sorted in time.

Despite my efforts to diagnose the problem, I had not been able to get it going as the next lap started so reluctantly had to withdraw.

As it turned out I'm not sure my knee would have lasted the full eight laps and I was certainly feeling the effects of four months with no exercise to speak off. Also I later discovered that I couldn't have fixed the bike anyway but that's for the next blog.