Sunday, 3 February 2019

Honda CB250K3


When the front forks collapsed I was gobsmacked! Okay, it was an 18 year old CB250K3, but the rat had managed to do a credible 53000 miles in the past five years, hauling me back and forth to work, in addition to the 42100 miles that were already on the clock. Luckily (if you can call it luck), when the front forks collapsed I was in heavy traffic only doing a few mph. The front end slowly unfurled until the engine was left implanted in the tarmac.

Curious pedestrians gathered to see this spontaneous piece of modern, (once) moving sculpture. Few offered me a hand out of the mess but then as a 58 year old who sports ex-army gear that looks like it's seen quite a few battles in its time, few people seem to want anything to do with me. Which is fine by me. At least most of the time, I would at that moment have appreciated a hand hauling the Honda out of the road on to the pavement.

It has to be admitted that even before this structural collapse the Honda did not look much better than myself in exterior appearance. Mainly because I could not bear to part with my hard earned money unless it proved absolutely necessary. Further examination of the wreck revealed that the culprit was the lower yoke which had torn in half, allowing the forks to move freely upwards. I staggered off to summon a rescue crew one of my boys had a Transit and he could earn his keep for once.

A mate was blackmailed into making up a lower yoke out of some alloy plate I had stashed away. The resulting inch thick lump was a bit of overkill but under the circumstances I felt it was better to be safe than sorry.

Having started at near the end of the story, that piece of anarchy happening about a month ago and being much the most spectacular moment in my life on the Honda, I had better quickly go back to the beginning.

I bought the Honda as a non-runner for £25 in good cosmetic nick. The problem turned out to be nothing more than an air filter that had evidently not been touched since the bike was manufactured. Its removal resulted in a running motor. Rather than pay the obnoxious local dealer an exorbitant sum for a replacement, I modified a car item to fit, which has since not been touched, so must have been OK. Admittedly, more by luck than any judgement or skill on my part.

Subsequent problems were mostly contained within the top end area of the engine. Although more petulant readers might consider the Honda’s gearbox a large problem, myself I find it an excellent anti-theft device as only dogged persistence, years of acclimatization and a deft left foot result in consistent engagement of the five gears. Even then, an annoying habit of slipping out of gears in a thoroughly unpredictable manner adds to my years and does nothing for engine longevity, what with the revs screaming into the red.

The first major problem was a cracked set of pistons that went in such an identical manner that I took it as a sign of divine retribution for sins in a past life. The pattern set that replaced them lasted 2746 miles... much to my horror I was forced to make the local dealer's day by buying original pistons at full retail - at least they have since refused to do a repeat performance. Touch wood! (Or said dealer’s head!).

No, next on the agenda, 15000 miles later, was the camshaft. No, not the bearings, which were fine because I always did a regular oil change at 800 miles and even occasionally cleaned out the centrifugal filter, but the lobes were so badly pitted that most of the hardening had disappeared, making valve clearance adjustments a 100 mile chore! They were re-welded and machined back into shape. No problems since in that area, although the top end is now producing some pretty horrible rattles.

Other horrors included cracked rubber carb manifolds (a real sod to find if you are not aware of the potential problem), a clutch pushrod seal that leaked chronically (a new one shoved in every 3000 miles) and would drain the engine of oil in twenty miles if you neglected it for too long, and carbs that needed replacing with 72000 miles on the clock. Overall, that’s not a bad tally for a much abused 250cc vertical twin that has nearly gone around the clock.

But, that's just the engine. There's also the chassis to consider. In the early seventies, the Japanese equipped their machines from new with terrible suspension. Mine still had the original forks and shocks untouched by human hand! I won't bore you with tales of highway indignity, let’s just say it was bad enough to give a Kawasaki triple owner sleepless nights.

The usual ploys were tried... set of Girling shocks, tougher springs, thicker oil. Yes, you've heard it all before, but the result wasn’t as expected, the Honda still rode like it had a frame made out of rubber. Not until some decent metal swinging arm bushes were made up and fitted did some semblance of tautness return to the chassis. Even then, it was a nasty wobbler above 75mph, which wasn’t as bad as it sounds as I rarely went that fast.

The other problem with the chassis was rust. Everything that was made out of steel rusted away at an incredible rate. In early seventies bikes everything except the engine and tyres were made out of steel... This was part of the reason why I have let the machine degenerate so badly. There was little point spending hours polishing up a bit of chrome only the next day to find it back to normal; more rust than gleam. Better to give everything a protective coating of road grime!

The front mudguard was the first item of any consequence to rust through. Falling off on to the tyre provided a moment’s bemusement until the whole front end locked up and pitched me off the bike. I didn’t bother putting a metal guard back on, I knew that within days it too would become infected. A nice GRP job was acquired and with a bit of modification fitted on like it was meant for the job. The first jaunt down the road persuaded me, like yesterday, to make up a metal brace to stop the forks twitching.

Second piece of note to give up the cause was the non-standard seat pan which rusted through to the extent that it detached from the bike whilst I was bowling along at 50mph. Very funny. Frightened the life out of me, actually, I thought the frame was splitting in two - a few layers of GRP were laid down over the remnants but this has now gone a suspicious murky brown colour...

One rear shock stud was given some additional welding before it had a chance to break off. I'm not that stupid. Similarly, the rear guard was replaced by another plastic item minutes before it was due to fall on the back tyre. A rear light, also moulded in plastic, was persuaded on to this in place of the huge bit of metal that had been bolted to the old guard. This cured the rear bulb’s habit of blowing every 400 miles, by way of an unexpected bonus.

Whilst at the back end it's worth mentioning that even using Honda wheel bearings meant life was less than 10000 miles a throw. You know when the bearings start to go because it throws the bike into a vicious tank slapper at about 35mph... which, thinking about it, is a lot better than doing the same at 75mph!

On the subject of tanks, the Honda item started seeping out petrol at about 53000 miles. Yep, rusted right through from the inside out. I was tempted to cover that in a few layers of GRP but I picked up a huge alloy tank that, after relocating the seat a few inches back, was persuaded to fit with a few old inner tubes for insulation.

Things like the original silencers were long gone, although the double skinned downpipes have yet to rust through completely, although judging by the complete layer of rust on the outside it's only a matter of months - in fact, they have been like that for years! Various silencers have been fitted with varying degrees of longevity and carburation fidelity. Sixties Bonnie style pipes seem most suited to the engine, although my hearing has long since gone. Rot is endemic to this bike, affecting not just steel but the wiring (the electrical problems could fill a book) and rubber.

The drum brakes are still there, although it's getting increasingly difficult to obtain cheap, decent shoes for them. The TLS front has saved my life on quite a few occasions, although I have become rather paranoid about the drums cracking up, which I hear is a common problem on high mileage bikes. That could really be one for the obituary columns.

But there you go. That's the nature of the beast. She creaks along like the old age pensioner that I am near to becoming. I can't afford to buy anything better and can't afford to put her to rest, the state of public transport being what it is, these days.

The CB has lasted a lot longer than I ever expected. The list of problems reads long, but they have come one at a time and been easy and cheap enough to deal with in consequence. Running costs are next to nothing because I always refit her with used stuff and petrol is still reasonable at 55mpg. If I had the money I would buy a new one, but I haven’t and they don't make them like this any more!

Charles Lear