Here in the UK we live under an authoritarian regime that insists we have every vehicle aged over 3 years old tested by a professional so that we can all be sure that every vehicle on the road is perfectly safe and road worthy. Despite having bikes pass with ruined wheel bearings and wobbly rear sprockets that nearly catch on the inside of the swingarm (!) I was pretty sure that a simple, inconsequential hole in one side of the exhaust would constitute a fail and a recommendation I ride the venerable CB250 to the nearest scrap yard. Something had to be done! And that something had to be cheap, and hopefully easy. Thankfully such a thing exists, but it is almost entirely confined to the car world for some reason. That thing is an exhaust repair bandage..
This is the CB250. As you can see, despite having 87200 miles and 23 years of abuse under its wheels it is still in showroom condition.
But follow the rules we must. More civilised countries such as France have no road worthiness test for two wheelers despite being in the EU and pretending to follow all their rules, but let's not get side tracked. On the underside of the exhaust, near the balance pipe, there is a hole. And this is a problem for the government for some reason.
Okay, when I say hole I mean part of the exhaust has dissolved. But let us not get bogged down in the details! Interestingly you can see the end of the inner pipe that runs down from the head, I guess that is what is rattling about when the exhaust gets hot.
Now I didn't like this as it cost money, £2.49 in fact, but I needed some kind of repair kit. I got one of these. The one from Holt was 50p more, so they can bugger off - CarPlan sounds fine to me.
Step one, wire brush that 'zorst until it's clean.
Sparkling!
This also exposed another hole on the top. A curious development, but no problem as I'll hopefully be wrapping the whole lot anyway.
Closer examination reveals the exhaust is actually about to break around the balance pipe but as long as it isn't blowing when The Man is looking at it I'll get a pass certificate, and that is all that matters. Always play the game.
Step two - cut a bit of foil (supplied in the kit) to cover holes and act as a "flame guard" so that the repair wrap doesn't burn or something. Easy enough!
Ah, beautiful. Now, wrestle with the stupid wrap stuff..
Separate both plastic sides from the wrap, the instructions say. The sticky, tacky wrap. Hahaha.. What planet are they on?? Maybe the Holt stuff is easier to use.
The actual instruction is to run the vehicle until the exhaust is warm, separate the black wrap from the blue plastic and wrap it round tightly to repair. There are several problems with this - the exhaust is only hot enough to make the wrap stick by the time it is hot enough to burn you, and it is impossible to wrap it tightly when you're faffing about layering the wrap on and peeling the remaining blue plastic off the other side, while the engine is running to keep the exhaust hot enough.. Ugh. Eventually, after getting really tacky black stuff all over my fingers, I got this:
Then simply tie some wire around it (also supplied, though not enough for two repairs..) so that it doesn't all fall off. Just twist the ends with pliers to tighten.
And lo, the exhaust is factory fresh. Run the vehicle for 20 minutes or go for a gentle drive, say the instructions.. The black stuff melts and then goes hard, but this also makes the wrap go a bit saggy. Mine is still melting after about 50 miles but the "repair" seems to be holding and, most importantly, I have gained an MOT and am allowed to use the bike on UK roads for another year. Thank goodness for that!
During my razz around Cornwall in April 2017 I found the chain to be stretching at a most alarming rate. Finally, with 40649 miles under its rollers (!) the trusty DID VM that I fitted way back in November 2011 had stretched to the point where there was no more adjustment left on the chain adjusters and it was still slack. It was so worn that the links didn't really fit the holes in the sprockets any more, there was too much length between each one! So worn, in fact, that I could almost pull the chain around the teeth of the rear sprocket.. Something had to be done. At the same time both front and rear sprockets were hooked and the cush rubbers in the rear wheel had long since given up on the idea of being useful, while the rear wheel bearings were so stiff I could barely turn them by hand - work was required. The saga of the cush rubbers is in the post previous to this, and what a joy that was. Anyway, the first step is actually kind of fun - find the rivet link in the chain (this will hopefully be a little softer than the rest), arm yourself with an angle grinder and grind the ends off the links.
This really wasn't enough. More grinding required!
The only real test of chain wear is to bend it sideways. This shows how much the links have elongated their holes in the plates. Here is the old VM, she did me proud..
That's really very bad. For comparison here is the new chain:
Quite a difference!
I am always interested in trying new brands, and saving money, so after much deliberation I ended up buying a kit from an ebay seller based in Germany - I would get a 104 link X ring chain from XAM, who seem a popular make in Germany and Australia and are of Japanese manufacture so should be good, and sprockets from a selection of manufacturers - you get whatever they have in stock. I got lucky and unlucky in that they supplied an AFAM front sprocket (yuck) and an Esjot rear (interesting!).
Annoyingly they supplied the wrong rear sprocket, Esjot part number 50-32013-31 (JT part 279.31) which is the part for a CMX250C - I need Esjot part 50-32032-31 (JT part 272.31). The two are close, but the base thickness/offset is different. This made it really hard to fit, and I had to use an old washer underneath the new Esjot to make it sit in the correct position. No good sending it back to Germany of course, the postage would be horrendous. Bugger!
The more shallow base also made doing up the nuts harder as the peg things kept spinning round, I found it best to lever the whole lot away from the sprocket with a small screwdriver while twirling a ratchet around on the nut. I should've just bought my own bits separately of course, never trust anyone to provide the right parts if they don't specify part numbers.. Live and learn. And learn. And learn again.. This also means the peg stud things poke out quite a way from the sprocket, almost grazing the swingarm, and aren't as far in to the cush rubbers as they should be. There is nothing good about this situation at all, other than it all fits nice and snug.
Soon enough, it was all together.
The rivet link is right where the Scottoiler tubes are. Riveting a chain is quite a game and a very messy business, the sooner chains go away the better!
Ta da! I must admit I'm also dubious on the merits of painting a sprocket, such as Esjot seem to do - surely the paint will just wear away and cover everything? Never mind, I'm sure they know what they're doing..
For the past.. Uhh.. 20,000 miles or so, the rear sprocket on the CB250 has been flapping about, side to side, at one point so badly that the ends of the studs were once very nearly grazing the inside of the swingarm. This didn't stop it from passing MOTs of course, a locked solid rear wheel not being anywhere near as serious as a left handlebar grip that can eventually be worked off, but I knew in my heart of hearts that it was really bleedin' unsafe. I took a lot of play out by replacing the washer and circlip that hold the sprocket in place but this wasn't fixing the root cause of the issue - the root cause was that the pegs that the sprocket bolts to were being able to slap around inside the (poorly designed, very difficult to replace) cush rubbers. A quick search of the Internet shows there are quite a few CG125 owners facing a similar problem, but if other people can do it why can't I? So it begins..
Firstly, get the wheel out.
So far, so familiar. With the sprocket still held in place by the circlip, undo the nuts. Then "simply" remove the circlip (you have some circlip pliars to hand, right? And some flathead screwdrivers?), the washer, and pull the whole lot off. Say hello to the little things that are about to cause you a whole heap of trouble..
Those things there are what Honda laughably consider to be cush rubbers. In a time long past these were big wedge things that were really easy to replace.. But not now. Not at this moment. Right now we have to deal with a cost cutting exercise of easily pressed in cylinders of broken rubber and misery. You may not be able to tell from the image but the inside sleeve of all these are slightly oval, this is enough to allow the sprocket to float around. The pegs in the sprocket are also worn, allowing yet more slop.
Marvellous design. Couldn't be better. Glad it's not a bunch of wedges I could replace in 2 minutes.
At this point I was a bit stumped. I tried hammering the inner sleeve but this achieved nothing, the rubber simply absorbing the shock. A quick search of ebay showed a replacement wheel could be procured for £75, a quick search of Wemoto showed a set of replacement cush rubbers was £15 so I can spend money on a special tool and still come out ahead. But what could that tool be? Ooooohhh!! £33.50 was all it took to have a blind bearing puller set in my grubby mitts. As Delia Smith would say, LE'S BE 'AVIN' YOU.
I went straight for the rubber which I'd had the most success with, having managed to break the inner sleeve away from it's snug rubber home. Hnnnggg..
YESSSSS! Sadly the other three rubbers laughed off my attempts at freeing them from their confines, just giving me a lot of this:
And this..
This was quite annoying, so I moved on to my go-to weapon of destruction - the cheap Dremel knock off. It's a shame it came to this, but desperation had long since set in. With a little router type tool in the end I set about attacking the rubber.
Success came at a price, not only is that router bit covered in rubber but there is now rubber all over the drive, all over one of my work t shirts, it was all over my fingers and it's all over several tools. The rubber doesn't go back to how it was, it stays tacky and sticky, and smears all over everything. If you do this then lay a cloth down on the floor and wear overalls or something. Also make sure you're wearing long sleeves, the rubber splattered up my arm and I ended up with quite a few blisters from burn marks on the underside of my left arm. What a job!
A couple of days later I set to it again, cleaning the remnants of rubber from the inside of the outer sleeves.
Getting there! They have to be scrupulously clean though for the puller things to slide in. Grind grind grind with the Dremel.. Eventually this can happen:
The lip on the very bottom of the puller insert can get underneath the sleeve, and then you can use the slide hammer to knock/pull it straight out. This was pleasingly easy. The aftermath..
That's the hard bit out of the way!
Once your package has finally arrived from Wemoto you can get back to work. This bit is quite simple, just knock them in.
I initially tried using an old front sprocket to make sure they new rubbers were going in straight and I wasn't mashing an old outer too much..
But this was silly. I soon changed to just mashing the outer with the hammer, this was much easier. Soon enough, this happened!
Weyhey! If anyone cares (or if it makes finding these cush rubbers any easier) they are made by a company called Washi and the part number on the bag is W41241-KB4-003. I'm not quite convinced that these are exactly the same as the originals as the steel inner sleeve seems a little thinner, but they'll do - they're certainly better than what I've pulled out!
With the cush rubbers in place I decided to also replace the wheel bearings. I quite like that the wheel has a couple of faces in the hub to knock the bearings down on to, this saves knocking them on to the spacer tube too tight and you also know right when they are properly seated.
I ground down the outside of one of the old bearings until it was a loose fit in the wheel, and then hammered on that to drive the new bearings (6302RS SKF Explorers of course) and the seal (91257-230-003) in to place. Dead easy. Soon enough, with replacement sprocket stud peg things because the old ones have worn oval (4 x 90128-KK4-000), and a new circlip and washer because the old ones have worn thin due to everything flapping about (90664-216-000 and 41202-KB4-000) it was all done.
Easy as that.
**UPDATE**
I was about to go on a sizeable Euro-jolly so had the rear tyre replaced, at this point the new cush rubbers had been in for 1931 miles. While carrying the wheel and new tyre to the tyre man, I could hear the sprocket rattling away. I thought nothing of it until I got back home and went to put the wheel in, only then did I notice the new Washi cush rubbers were in a very poor state, rubber visibly being pushed out of the holes! I had no time to change which bike I was taking, so had to ignore it and set off anyway.
At Limoges in France, with something like 2400 miles on the rubbers, I had to use an angle grinder to remove the excess length of the new sprocket studs as the whole lot was wobbling around so much that the studs were starting to rub on the inside of the swinging arm!
At 5815 miles I arrived home, having been through Spain and France, and found this horror:
There was so little metal left on the lip of the wheel that the sprocket could have broken free at any time. And to show how little rubber was left..
Time to remove the sprocket.. In doing so the last slivers of metal broke off, the wheel now totally scrap. Thanks Washi!
The metal inners were no longer stuck to the rubber at all in most cases. Also the rubber had been squashed out of the way as if it were liquorice.
At this point I wholeheartedly recommend NOT fitting Washi cush rubbers to your CB250. I sent an email to Wemoto to point out that these are not fit for purpose and I was assured that they have notified Washi of my experience and that further testing would be carried out. I have no update on whether anything has been changed 5 months later.
Thankfully, there is hope -helpful commenter ThePerkinsFocus has pointed out that replacement rubbers can be purchased from Honda under the part number 41241-KB4-003. I absolutely recommend you buy these instead, I wish I'd known about them before buying a highly inferior aftermarket version. They're not even any more expensive! Lesson learned.
