Nice step-by-step written by the-rodster over on the JJ on how to fab up your own exhaust on the cheap. Easy to follow pics, well executed and some great looking pipes. Click over to check it out then go get your hands dirty. Build You Own Motorcycle Pipes

Swaping Carbs via
101 Harley-Davidson Performance Projects
By Kenna Love, Kip Woodring

It’s been a while since I’ve posted a free e-book for download, so here’s a real good one - submitted by our friend Gazza - for you to sink your teeth into. Hailing from the year 1898 and dubbed “Modern Letter Engraving”, this is a sweet romp though the skill of metal engraving (in case you couldn’t tell by the title). While its filigree and ornate lettering were never intented for the hardcore, D.I.Y bike builder, few things can give a bike some real “oh wow” factor as some well done, tasteful engraving. Good stuff, many thanks to Gazza for sending it in.

To download the PDF file, click the following link: Modern Metal Engraving

To learn more about our free ebook series, go here
And to see other free eBooks that have been posted, go here

Some old school love from Street Chopper on how to work some molding and sculpting magic on your gas tank. They use a honda tank as an example, but obviously it will work with other tanks. Click the pics for some full size goodness - thanks to glory days for the scans.

The folks at Caswell put together this pretty solid overview on the basics of metal polishing. Obviously a good marketing tool for them to sell more products, but the info is legit and I like it when I see a company trying to educate their customer instead of trying to pull a fast one on them. If the ins & outs of metal polishing seem like black magic to you, click the image below to download the PDF and get up to speed.

Here’s a quick overview article about frame welding that I picked up off the Miller website and turned into a PDF for easy download. I’d consider this an intro article - all great info that you need to know, but if you don’t know it already, and don’t have the experience to back it up, you should NOT be welding a frame. If you like the idea of building your own frame and want to learn more about it, it’s something to read to get you started in the process, but what you’ll need after that is many hours of hands on experience. I’m all for the do-it-yourself ethic, but welding up a frame after you read an article and bought your first welder is just straight up stupid. By all means, devour all the information you can, but know when and where to draw the line and call in a professional. Regardless, some good info in the piece, even if you have no interest in welding up a frame, if you’re into building bikes, it’s good stuff to know. To download the PDF, click on the image below.

Here’s a quick download for you that goes through the basics of motorcycle fuel systems, specifically carburetors. Great for the greenhorn or old timer who needs a refresher. Click the image below to download the pdf.

Another free book for you cats to download, this one’s called Elementary Metal Work. More along the craftsman / artisan line of things, but as always, there are good things to pick up and take away that you could apply to bike building.

To download the PDF file, click the following link: Elementary Metal Work

To learn more about our free ebook series, go here
And to see other free eBooks that have been posted, go here

Rod Gibson gets to grips with the science of camshaft design, and enters a world full of ramps, overlap, lift and durations. But will it make the bike go faster?
We tend to take camshafts for granted, or at least I did until quite recently. Coaxing a little more power out of our project Katana meant that, like it or not, I had to get to grips with a little cam technology. But before we plunge too deeply into the strange world of ramps, overlap and durations, here’s a quick trip around the trusty camshaft and its place in the world of internal combustion.

Any engine has to have some provision to get gas in and out of its cylinders. In a conventional four-stroke engine the job of the inlet valve is to open to allow fresh charge into each cylinder, then close to allow it to be compressed and ignited. After combustion, the exhaust valve opens to let the spent gasses out, then closes to allow the whole cycle to repeat.

To read the rest of this article, download the pdf by clicking on the thumbnail below

I’ll admit to not really reading through this latest ebook, but the subject falls perfectly inline with the D.I.Y. Knucklebuster attitude, so I figured I’d post it. I’m not sure how often you’re going to need to know how to color metal and bronzing, but when you do, you’ll have this book to help you through. Granted, this book is from the late 1800s and new techniques have been developed BUT as always, there is plenty of good knowledge to pick up within these pages. Plus, who says the new techniques are better than the old ones? They might be easier, but is the final product actually better? I’m not sure, but there are plenty of examples of craftsmanship that have lasted the test of time. Anyway, enough rambling…

To download the PDF file, click the following link: Metal Coloring and Bronzing

To learn more about our free ebook series, go here
And to see other free eBooks that have been posted, go here

Pull Technique

The latest in our free e-book series, this little ditty is a great basic overview of a wide range of metal working tools and techniques. Checking in from the year 1903, it’s definitely an introduction, so it’s perfect for you newbs, but also a lot of great tips and history of how things used to be done for you guys who’ve been around the block a few times.

To download the PDF file, click the following link: Basic Metal Working Manual

To learn more about our free ebook series, go here
And to see other free eBooks that have been posted, go here

Push Technique

So the guys at Standard Abrasives put together this little D.I.Y guide about engine prep. It’s geared towards car engines and it’s heavy on the product push BUT it’s solid information and a lot of it will translate over to motorcycle engines. Consider the techniques they discuss more than what they’re actually doing it on and the brand of product they’re using.

Block Preparation
Engine block preparation is the cleaning and abrasive operations performed to an engine’s cylinder block prior to the machining operations (boring, honing, align boring, balancing, etc.) that set the block’s critical dimensions. For the purposes of this Guide, we’re going to look at block preparation in a wider sense and include work on the crankshaft, the connecting rods and the pistons.

Download the pdf by clicking the image below.

Check out this PDF that has the guys from Classic Motorcycle Mechanics tearing down a beat down and battered 1974 Kawasaki Z1A. They go through every little as they tear it down to bare motor and frame. Lots of detailed pics and commentary, plus it’s a small, 500KB file, so it will download quick. Plenty of good info that would cross over to other bikes needing a tear down and rebuild. Print it out, and read it on the can - good stuff.

click the image below to download the article as a PDF

A little Q & A from Classic Motorcycle Mechanics to help you get through setting up the crankshaft and bearings on a CB 400. Click the image to enlarge the piece so you can see all the info better, or just read through the text below.

Can you help me with setting up a crankshaft and bearings in a 1975 CB 400F?

It’s supposed to be a case of measuring the size of the crankcase in-line boring, measuring the diameter of the crankshaft journals and then selecting the correct size shells by colour to get the correct running clearance. Same technique for con rods too. Unfortunately, it is just practically impossible to do this. It would also be impractically expensive to buy all the different size shells and then selectively assemble. Can/should the crank/big ends be assembled and then Plastigauged for reassurance? Again, nowhere can I find what the running clearance of the bearings should be. I am completely baffled. Help!
John Clement, Victoria, Australia

You’re quite correct in that the shells were originally colour coded to match the machining tolerances. Think of it this way: The crank journals and bearing housings in the cases and con rods would have been machined on the production line to a target size. After machining, they were then measured to see how close they were to target. Bearing shells were then selected from one of three sizes (thick, medium and thin) to bring the bearing clearances to bang on target. This practice is called ‘grading’ and is commonly used to ensure a precision fit (BMW use a similar process to match pistons to cylinder bores, for instance). The three bearing shell sizes were marked with a lick of paint on the edge to identify the grade, though all three shells were stamped ‘STD’ on the back – which is, in fact, quite meaningless as no ‘oversize’ shells were ever supplied for regrinds. The numbers stamped on the crank webs and crankcases are codes, which identify the precise measurement of the bearing housings, and can be used to select the graded shells on the production line.

However (and this is where it all goes pear shaped), the numbers will only tell you what size the journals were when the crank was new – not after 30 years and half a million miles – so they aren’t useful now. Truth is the difference between graded bearing shell thicknesses is so tiny as to be academic, and standard practice when reconditioning an old engine is to fit the thickest shells to compensate for wear. These are usually coded black.

For a more accurate check, use Plastigauge. You should be getting a reading of 0.041 to 0.071 if the bearing clearance is still within factory tolerances. RG.

It’s been a while since I’ve posted a free e-book for you cats to download, so it’s time to start that tradition back up again. I’ve got my greasy paws on a handful of “new” old books for you guys to dig into. Not sure about you, but I love reading through this old stuff. Not only to pick up tips and tricks from days of yore, but also to get a better understanding and sense of history into these crafts - from welding to machining to general metal work and casting - evolved through time. A great way to get the most of out these books is to print them out, then three hole punch them and put them in a 3-ring binder. Then you can carry it with ya whenever you know your going to have some down time (waiting at an airport, sitting on the can, going to the in-laws house… etc). Reading them on the computer kind of blows, to really get the most out of the books, I think printing them is the way to go.

For this installment I’ve got the Metal Turners Handy Book by P.N. Hasluck. This one is all about different types of lathes, the accompanying tooling, uses, etc. Tons of pics and stacks of info and generally an easy read.

To download the PDF file, click the following link: The Metal Turner’s Handybook

To learn more about our free ebook series, go here
And to see other free eBooks that have been posted, go here

Technical guru Mark Haycock delves into the mysterious world of ignition systems, and reveals why getting it back to front is sometimes quite OK.

I had a letter recently from one of our readers, Mr A Birch, raising questions about the
workings of an ignition coil so I thought it might be an idea to take a closer look, in particular at
the principle of the ‘wasted spark’.

What we call an ignition coil is actually an example of a so-called induction coil. It is
merely a specialised electrical transformer, the purpose being to greatly increase the voltage
provided by the battery. Despite its name, like any other simple transformer it actually
contains two coils of wire, or windings, one for the low-voltage side (the primary) and the other for the high-voltage (the secondary).

The windings are concentric, and wrapped around a central core made from laminations
(thin sheets) of iron. The core is usually not visible, but in old-style Honda coils it extends
out of the enclosing plastic case (Picture 1). Incidentally, the word ‘voltage’ is sometimes
replaced by ‘tension’ when dealing with ignition coils.

There are considerably more turns in the secondary windings than the primary, and it is
this that leads to the increase in voltage. What causes the output of high tension is a
change in the flow of current through the low-tension windings, with that change traditionally
being brought about by the contact breaker. The aim is to reduce the current to zero as
rapidly as possible. This ‘induces’ a high voltage in the secondary windings, which is fed to the spark plug.
To read the rest of the article,
click the image below to download it as a PDF

Setscew or bolt? Stainless or zinc plate? Technical boffin Mark Haycock gets to grips with screws, bolts and nuts; and advises what you should be using, where and why.

To read the whole article, download the pdf: Screws & Fasteners 101

Setting carb float levels is still considered a black art – but getting it right can make a significant difference to your bike’s economy and performance. Rod Gibson explains all.
So what is a float level, and why does it matter? Deep within the confines of your carburettors lurk a number of jets, whose job it is to draw in fuel, mix it with the air and send it to the engine to be burned. Those jets need to have a readily available reservoir of petrol, so each carb has a chamber fitted at its lower end that is fed with petrol from the fuel tank.
The amount of fuel in the chamber has to be controlled – too much and the surplus fuel will run out of the overflows, too little and the jets will only have air to suck in, and the engine won’t run. So far so simple, but it’s actually a bit more subtle than that, for if there’s insufficient fuel in the float chamber the bike can run weak at full throttle when there’s not enough petrol in the carb to keep up with the demands of the main jet. Conversely, having too much petrol in the chamber can make the bike run rich – but an excess of petrol usually leads to flooding problems.
To read the rest of this article, download the pdf: Setting Carb Float Levels