For many years now I ve been buying and using small motorcycle 6volt acid filled batteries for my engines with great success.  Some of them have lasted for 4 to 5 years.   They used to come with the acid seperate to be put in and then charged.  The acid container usually had just enough to fill the battery and very little extra.   Now for some reason they enclose enough acid to fill three to four batteries with a recloseable cap for storage if wanted.    I got curious about all the excess and asked the manager of the auto department at a local Farm n Fleet store about this extra acid.   His response was just use it to refill your batteries as the acid disapates.   I was some what concerned with this response and asked if that was a safe practise?   He said it was ok.   I quess I was told many years ago that that could cause severe damage to a battery, may even cause it to blow up.   Would like to hear everybodys response on this one.
thankyou in advance,
Curt Andree This email address is being protected from spambots. You need JavaScript enabled to view it.


I was always told that the water evaporates not the acid.
Rick Kramer This email address is being protected from spambots. You need JavaScript enabled to view it.


This is one of the reasons why I use the batteries that are intended for computer backup power supplies.
They last forever, and are intended to be used slightly, then recharged, over and over and over again.
They are also small, and easy to carry. They are totally sealed so you can arrange them however you want.
The terminals are easy to connect to, and you never need to worry whether you have a strong connection.
Also, many companies throw these batteries out as a matter of course every couple of years. They are cheap enough to not warrant risking the backup of a company’s computers, but they are more than adequate for old iron.

-Tim This email address is being protected from spambots. You need JavaScript enabled to view it.


It's very bad practice to top up a battery with acid.  As a battery is charged it releases hydrogen and oxygen form the postive and negative plates.  This is the electricity breakingdown water into it's component elements.  This is where the water goes, along with a bit of evaporation.  Hence, you should only top up a battery with distilled water to replace the lost water.  If you top the battery up with acid you will slowly increase the concentration of the acid in the battery which will damage it.
Kind regards
Mark This email address is being protected from spambots. You need JavaScript enabled to view it.


All very true. However, a battery that's old, particularly one that's been allowed to sit partially discharged for some time, will develop sulfation of the plates. Normally the active material of both plates converts to lead sulfate as the battery discharges, then on charging it's converted back to lead dioxide (or peroxide, it's sometimes called) on one plate and spongy metallic lead on the other. But if the lead sulfate sits for long it crystallizes so it won't easily reconvert with charging. The battery loses capacity from this material that's effectively inert, and it also binds up sulfuric acid as sulfate and the battery can't be charged back to the normal electrolyte specific gravity if it's kept filled to the normal level with water. Thus it can't be charged to full voltage. I've managed to revive several such batteries for another season by charging them to full voltage (which can only occur with the electrolyte level considerably down), then mixing sulfuric acid to the normal specific gravity of a charged battery (1.280, I think) and topping up the electrolyte with it. You get a battery of reduced amp-hour capacity but normal voltage. Once. It's not something to do with a battery in an important application where failure would be a big problem. Sooner or later some of the crumbling sulfate debris will short out a cell and the battery's DEAD. New car batteries seem to usually die suddenly without the period of weak operation and rapid discharging we used to expect. Must have something to do with the plate structure.

John This email address is being protected from spambots. You need JavaScript enabled to view it.


The Moron who gave you that advice should be out looking for another job, as of yesterday!! To do that is DANGEROUS!
Reg & Marg Ingold.
Newcastle, NSW, Australia.
This email address is being protected from spambots. You need JavaScript enabled to view it.


Thankyou very much Mark, that was what I had been taught way back in school while in shop classes.......I am 55 now and still remember that lesson, just thought maybe I had missed something over the years.
Curt Andree


Ah yes Reg even the good guys from down under know lots too.....I thought I was forgetting something over the years, thanks for refreshing my keen memory.   Damn dangerous if my techings were correct and yes I plan to discuss the issue with this guys manager....he is an old friend of mine and would want to know about wrong info given out to the stores customers.
Curt Andree


I've got a couple of the Makita cordless drills which use the 9.6v rechargable battery.  Since I've also got several extra batteries, I've started using those batteries for my engines.

There's a couple things I like about using the cordless drill batteries.

1. Super easy to recharge.  The cordless drills come with a charger for the batteries and it is quick and simple to use.  I find this a great feature compared to using other small size batteries which you often cannot charge with a regular automotive battery charger.

2. A single battery charge has been enough for a weekend show.  Actually I really don't know how long I can run a engine off the cordless drill battery as I usually use a freshly charged battery for each show.

3. I also find the size and design of the Makita battery to be great. They easily fit inside a battery box and if a person took the time to make a socket for the battery to fit into then changing batteries would be super quick and simple.

George This email address is being protected from spambots. You need JavaScript enabled to view it.

Read more: Batteries & Acid

Where do I start?

People who are thinking of joining the hobby of restoring old iron (a common term for antique engines) usually have little or no idea of where or how to get started. This email address is being protected from spambots. You need JavaScript enabled to view it. has some good advice:

Read more: Beginners Advice

Building a transporter/cart for your engine
Seemingly the easiest part of your restoration, anyone who has attempted to make a transporter or cart for their engine will tell you that it is not as easy as it looks! During a discussion on the subject on the Stationary Engine Mailing List - Brad Soward posted the following definitive article on building a steel cart, in further off list discussion, Peter Forbes contributed his method of building larger carts for large engines.

Read more: Building a transporter/cart for your engine

Brad Soward explained the concepts behind Bore & Stroke after a question on the SEL...

When the specs on an engine says it is a 5 x 7 inch bore and stroke does
this mean that the cylinder diameter is 5" and the stroke is 7"? if this is
and I was going to measure the taper in the cylinder would I need a bore
gage that would measure down to 7" in depth?>

I see that you've received several replies which partially address your
questions, but I'm going to try to pull them all together in a more detailed
response which hopefully gives you all you need.

Bore x Stroke is commonly quoted in that form - bore diameter first followed
by stroke length. In our older and slower engines the stroke is normally
longer than the bore. I have a few older type engines where the bore and
stroke are the same, and this is referred to as a "square" design. It is
only in modern high speed engines that we generally see "oversquare"
dimensions where the stroke is shorter than the bore diameter.
When measuring a cylinder bore for wear we are interested in three things -
bore diameter compared to standard, taper and ovality. All you need to
measure all these is an inside micrometer, or a telescopic gauge with an
appropriate tool to read the dimension such as an outside micrometer or a
good vernier caliper. When measuring, remember that the rings don't go all
the way to the top of the bore, so at the very top there will be no
appreciable wear. Likewise at the very bottom of the bore. Use these to give
you the standard bore size if you don't have the specs.
Measure the bore diameter just below the uppermost extent of ring travel
(there is usually a 'lip' on a worn bore) and measure in two places 90
degrees apart. Make one measurement across the bore parallel with the wrist
pin and the other at right angles to the wrist pin. This last one is
measuring the 'thrust side' of the bore, and will probably be slightly
larger than the other measurement. The larger figure will give you the
amount the bore is worn from standard, and the difference between the two
readings is the ovality of the cylinder. Now repeat the measurements at the
bottom of the piston ring travel. Once again, the difference between the two
cross measurements gives you ovality, and now you can compare the readings
with those from the upper end. The difference between these figures gives
you the lengthwise taper in the cylinder. Unless the cylinder is very worn,
taper and ovality will probably not be an issue, but they are handy to know
if a rebore is being considered.
I hope I haven't oversimplified this for you Paul in trying to make it as
clear as I can.

Read more: Bore and Stroke Explained

I have some golden rules:

  • Whenever you are about to buy, determine a fair price elsewhere BEFORE you negotiate.
  • Never exceed your own price limit because you have become attached to an engine. It is better to walk away.
  • Play with the engine as much as you like - if the seller does not want you to do this then forget it - they have something to hide.
  • Pump the seller for as much information as you can.
  • ALWAYS GET A RECEIPT which has your name, the sellers name and address, the date, a description of what is sold complete with serial number(s), and the price. This is vital. A friend of mine purchased an engine and spent hundreds of hours and dollars rebuilding it only to have it recognised by its former owner at a show who claimed it had been stolen. In this situation you are likely to lose the engine, but the receipt should keep you out of jail. This advice is good for any purchase - not just engines. In the case of the friend the former owner was happy to see it had gone to a good home and just let the matter drop.…

Read more: Buying an engine