Small Engine Tools
fuelling system tools
A fuelling system fault, hands down is the most common fault a lawnmower will have. The reasons are simple, carburettors are small and block up with crap easily, check out this post “Lawn mower starts then dies”.
The second reason, people (including me) forget to use a fuel stabiliser in the gas tank over the winter (Keeps gas fresh). Check out this post “How to winterise your mower”.
Cleaning the fuelling system in most cases fixes the problem, Check this post out, “Carburettor cleaning”, but sometimes you’ll need to bite the bullet and fit a new carburettor.
Anyway here’s a list of the tools you’ll find really helpful if your troubleshooting your fuelling system.
Some of the pictures on this page link to Amazon.com where you can check price and delivery of products. We are a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for us to earn fees by linking to Amazon.com and affiliated sites.
Stabil Fuel stabiliser
Mix this with the gas when winterising your small engine. Gas isn't what it used to be, it goes stale, in some cases after just one month. Bad gas causes gumming and that's a carburettor killer. Stabiliser will save you money and stress in the long run. Picture links to Amazon.com
Fuel line clamp
Some small engines will have a gas tap, which is really handy when removing the carburettor, stops gas flowing all over the shop. However most engines won't have one, these useful clamps simply squeeze the fuel line and prevent a spill while you perform surgery. Picture links to Amazon.com
Ignition system tools
Every home needs a Dvom (Digital Volt Ohm Meter). It's used to check for continuity in lawn mower wiring, and for voltage when there's a battery fitted. But don't use this tool to check spark, that will kill it. I use mine everyday. I have the previous model to this and it's still doing its job. Picture links to Amazon.com
If you’re reading this section, you might have a more serous problem. But it doesn’t mean you can’t fix it. Small engines are really simple, they need 3 things:
- Gas/air mix
This tool will test compression, that in turn will help you identify common issues like head gasket failure, sticking valves or worn/broken piston rings.
Modern lawn mower engines use a compression release valve which help them start. Trouble is, a compression release valve will give you incorrect compression test readings.
So if your riding mower or walk behind mower was made in the last 15 years or so, you’ll need the leak-down tester.
It allows you accurately measure pressure loss in the cylinder (you’ll access to compressed air). But more importantly, it allows you listen for the tell tale leaking of air.
- Air from the dipstick indicates a broken or worn rings.
- Air leaking from exhaust/muffler suggests a exhaust valve issue.
- Air leaking from carburettor suggests an intake valve fault.
- Air from the cylinder head suggests a head gasket fault.
This is a compression tester, it's fitted in the plug hole using the adaptor. The engine is cranked over and a reading of how much compression the cylinder makes is captured on the gauge.
A low reading can be caused by a simple fault such as a sticking valve. Picture links to Amazon.com