CHANGING COOLANT HOSES
Steve Cooper shows us how.
If you own a liquid-cooled motorcycle then it’s kind of obvious that the coolant needs to stay where it is most needed. Leaking head gaskets either ooze down the engine so can you spot the leak or dribble water into the cylinder so you can’t! Water pumps can do likewise but both are generally fairly readily, if expensively, sorted. Stuff like Suzuki Kettles, Yamaha LCS, Honda Gold Wings are generally well supported with either OEM or pattern seals/gaskets. Where it gets a wee bit more complex is when you own a less common machine that’s suffering from incontinence but even then there are specialists who will tool up for bulk club or forum groups and knock out a batch of head or pump gaskets. Unfortunately it all gets a bit messier when it comes to coolant pipes. In most scenarios those black rubbery tubes are model specific fitments and therefore don’t have the economies of scale that, say, a water pump gasket does for Yamaha’s Powervalve and Banshee engines. And to compound the problem it’s even worse if your bike is something rare, or oddball like a Yamaha XV550 or a Honda VT250. Manufacturers are only obliged to supply spares for a certain period of time and once the stock has been used up that’s often game over. So what are the options? Simplistically there are two routes to choose from. If you can get support and input from like-minded enthusiasts, then providing you can generate sufficient firm orders, it’s possible to commission a limited run of ‘Lower Coolant Hose, Right Hand Side’. There are various companies around who will tool up but the volumes need to be viable. To produce any shaped hose it’s normally obligatory for the manufacturer to make a mandrel or former around which they can make the hose. Know that these are made from solid steel bar and generally at least £500 a pop and you can see why the companies that can, probably won’t if you and your mates can only drum custom for, say, a dozen ‘thermostat, bypass’ hoses. If, on the other hand, sufficient Kawasaki Z1300 owners want complete engine sets of hoses then it’s likely to be game on. If you are building a special then, to be honest, you don’t stand a chance and you will without exception, be designing and making your own coolant hoses. What follows below is an overview on options of how you might address the issue of being hose-less. Project Rickuki is in need of coolant pipes so we’ll be using it as our example.
Option one – make a pattern
If an owners’ club or group has committed to replicating complete new sets of hoses, then there’s a need to make a series of patterns from which mandrels or formers can be made. The rule of thumb here is that you’d need to provide some reasonably robust patterns from which your hose maker can work. Obviously you’ll need to provide IDS (internal dimensions or bore sizes) but other than that it’s your handiwork that dictates what’s produced. Phrases such as ‘well, bit more than a 90º bend, then turn right,’ etc. aren’t going to deliver the goods! The normal route is to map out the angles, turns and runs with some reasonable rigid wire that’s also fairly easily manipulated. If you can obtain them wire coat hangers are fine; if not some 3mm brass tube from a DIY shed will work just as well.
Option two – making your own hoses
Okay so reality kicks in and it’s only you that wants a set of custom made hoses for a Rickuki… er, well, actually that’ll be me! Without limitless dosh we’ll need another solution to our self-engineered problem. This is where you need to apply some lateral thought and hone those Blue Peter skills you thought you’d never use again. It’s possible to construct your own hoses from mass produced standard fittings and it just so happens that those nice chaps at Samco offer a huge range of products in a wide range of diameters, lengths and material constructions that should suit most applications. Armed with the correct array of pipes and fittings it should be possible to connect up pretty much any liquid cooled engine to its radiator and water pump. The only real head scratchers likely to catch anyone out will be metal spigots with unusual diameters not catered for by your chosen hose supplier. In instances like this try looking for Imperial hoses and have a reducer made to convert back to metric where appropriate.
Our thanks to… Samco http://www.silflex.com Phil Denton Engineering https:// phildentonengineering.com