Small engine help


Exhaust off and burn out with a wee drop of kerosene outside with an extinguisher handy. Try without to test?
With a bit of a rev on the engine block the intake between air box and carburetor, (hand over the intake) might just dislodge a restriction in a jet. Also check for air getting in between carb and engine, bit of WD40 in a spray can see if it picks up.


The original Honda problem:
Might be worth checking valve clearance if you have plenty of fuel and a spark?
Also worth throwing a bit (a cap full) of fuel into the carburetor (outside not in the shed) inlet, see if it runs different as it will have plenty of fuel? Again check for air leaks between carb and engine. Cylinder heads sometimes comes loose for no apparent reason?
What did you do fix that?
Ive been driving it around with the choke out thinking it might get to go but no luck,
I've been through all of this with my sons REV 3 125, the silencer has a replaceable 'wad' of material in it that do get full of oil, cheap and easy to replace just take the silencer apart and its there, you could always take the 'wad' out and try to run it with the silencer off and see if it helps.
There is loads of help online for the Beta carbs as they are notoriously difficult to set up and are temperamental but as others have said you will need to remove the carb, strip it and clean it, they are very easy to work on but need a bit of technique to remove in the first place.


The 2 stroke strimmers are the same, we just leave the "wad" also known as a spark arrestor (I think) out when refitting, they run better than new without.


west yorkshire
Now and a gain when starting due to turning it over a while it back fires and get a little flame from exhaust. Will take it off tomorrow... Granddad been having a look under rocker cover today, he said on the combustion stoke just before TDC the exhaust valve is presses but only very slightly, dose that sound right?


Are you lads turning it in the correct direction @snipe?
Exhaust valve will open at the bottom of the power stroke and stay open all through the exhaust stroke (piston coming up). At the top of the exhaust stroke the inlet valve will be open as well (so both valves will be open a bit, also known as valve overlap). Then exhaust valve closes and the inlet valve stays open until the piston is coming well up the compression stroke. Inlet closes and the piston continues up until Top Dead Centre (TDC) with both valves closed. Where you get a spark and the piston goes down on the power stroke. And it all happens again.

Hope this helps a bit ...........


Yes, just crank it on the starter / kick start / pull cord for correct direction.
Unlikely for timing to slip, but you never know ...............

With the piston at the top (TDC) and both valves closed have you clearance in the tappets?
About 0.3mm is the average clearance .........
Also worth checking tomorrow if not already checked?
Last edited:


Oh, wait a minute would it have an auto decompressor fitted?
It may well have ...............

I'll have to try and find out more for you, it helps pull starting the engine, but as soon as it starts it automatically closes the exhaust valve. Honda quad engines definitely have it fitted. If it has one fitted, you can rule out the second opening of the exhaust valve as the problem.

Is Red tractor detrimental to your mental health?

  • Yes, Red tractor increase my stress and anxiety

    Votes: 289 97.6%
  • No, Red tractor gives me peace of mind that the product I produce is safe to enter the food chain

    Votes: 7 2.4%

HSENI names new farm safety champions

  • 128
  • 0
Written by William Kellett from Agriland

The Health and Safety Executive for Northern Ireland (HSENI) alongside the Farm Safety Partnership (FSP), has named new farm safety champions and commended the outstanding work on farm safety that has been carried out in the farming community in the last 20 years.

Two of these champions are Malcom Downey, retired principal inspector for the Agri/Food team in HSENI and Harry Sinclair, current chair of the Farm Safety Partnership and former president of the Ulster Farmers’ Union (UFU).

Improving farm safety is the key aim of HSENI’s and the FSP’s work and...