Important Disclaimer
Advice given in this section may or may not be accurate, safe or wise. Always use common sense and when in doubt assume that any advice given herein is incorrect and liable to end in terminal engine or part failure and possible injury or death. www.ratbike.org and its contributors can accept no responsibility for anything, anywhere, regardless of cause.
Don't throw that old Keihin carb away!
Have you ever picked up an old CB750 or bought carbs online, only to find that the cast in the bowl where the main jet screws in is FUBAR?
I stumbled onto a quick and easy way to fix that. Here is a list of the parts you will need: .45 cal ACP pistol,... more
I stumbled onto a quick and easy way to fix that. Here is a list of the parts you will need: .45 cal ACP pistol,... more
Max (USA)
Diagnosing Electrical Shorts Circuits
This was taught to me by my first employer and is extremely useful:
If you have a short that blows the fuse, it gets expensive and frustrating when the fuse keeps blowing. Remove the fuse and replace it with a headlamp bulb. When you get a short, instead of blowing the... more
If you have a short that blows the fuse, it gets expensive and frustrating when the fuse keeps blowing. Remove the fuse and replace it with a headlamp bulb. When you get a short, instead of blowing the... more
Diesel Graham
Switching to Synthetic Oil
Never switch an old engine to synthetic oil. It's OK to run synthetic right from the start, or after a full rebuild when all gaskets were replaced, but switching later will cause all sorts of problems outweighing whatever benefit you expected.
Most engines that have been... more
Most engines that have been... more
Eddie - Canada
Replacment Airfilter
Air Filter Screwed....? Just get a piece of gauze and use a hose clamp to fashion a free flowing air filter.
Daryl (Mad Max) - UK
Seating a difficult tyre bead
(Method 1) If you have a spare car tyre on a rim, pump that up as hard as it will go - then use that as a reservoir to rapidly inflate your bike tyre.
(Method 2) Fit tyre to bike and ride around the block at half-pressure - the tyre will usually seat itself.
(Method 2) Fit tyre to bike and ride around the block at half-pressure - the tyre will usually seat itself.
SneakyPete - UK
Measuring Piston Rings
To get an accurate gap reading, always measure the rings three times:
Take off the cylinders. Measure the space between the edge of the ring and the edge of the ring groove in the piston. check the manual for the maximum allowable space.
Take the rings off the pistons.... more
Take off the cylinders. Measure the space between the edge of the ring and the edge of the ring groove in the piston. check the manual for the maximum allowable space.
Take the rings off the pistons.... more
PHM - USA
Replacement Intake Rubbers
I had a CB750 '82 model that hated me. It was what I believe
was the only model made that had a curved intake tube things.
The fuel inlet holes on the block had a curved rubber tube to go
to the perfectly lined up carburetors. The rubber tube things (no
idea what they... more
RazzleDazzle - Canada
Tips for Easy Brake Bleeding
Here's my method that I've worked up over the years. It's 100%
guaranteed to get all the air out of your brake system. It's based
on the fact that air in the brake system doesn't want to go down.
It wants to go up, so that's what you should encourage it to do.
Step... more
Step... more
Fred
Broken Plastics?
Get hold of a Lego brick in a matching colour,
place in glass jar and pour about a dessert
spoon of nail varnish remover (acetone) over it.
The resultant gooey mess will bond just about any
plastic panel - even fixed my press stud on my sidepanel.
SneakyPete
Carb running too rich at idle
I should have put this little gem on the tech tips ages ago: Since
ratbikers are always putting the wrong carbs on things and then fiddling about for
ages trying to get them right here's one quick cheap bodge if your carb is too rich
at the idle and low end no matter what you... more
Rex
DIY 2-stroke Expansion Chambers
For two-stroke riders looking for a cheap, power-producing alternative to aftermarket expansion chambers, try the following: find the point on your existing pipe(s) where the diameter becomes largest (usually a foot or so from the downstream end of the headpipe) and cut it (them)... more
Ben - USA
Insulating a Split Ignition Coil
If your ignition coil is split and leaking electricity insulate it with kit and tape. To keep the water away from the tape I put an empty red bull can (without the top) around the complete coil with tape and kit. This way it looks strange and it works great! I didnt have to buy... more
Rainier - Holland
Broken Oil Level Window?
If the sight windows in your clutch and brake master cylinders start leaking and oozing brake fluid everywhere, take the assemblies off and carefully punch out the windows from the inside w/ a drift... turn some aluminum/brass scrap into plugs to fit (or have a buddy do it for... more
Bart - USA
Motor Oil Overfill?
Filled your engine up with too much oil? You can always remove the oil plug. An easier way is to get on of those plant sprayers (or Glassex of something). Unscrew the spray gun, stick the tube in your oil filler gap, and you can suck the oil right out. Goes pretty fast if you remove the nozzle.
Steven - Belgium
Cheap O-Ring Fix
Use plumbers pipe tape for O rings instead of the leaky originals your carbs. Its cheep. Its always the right size. It works.
David Lent - USA
