Nearly new generator won't start

[mike42]

So about 6 weeks ago I bought a "cheap" generator from Screwfix.

Filled it with oil as per spec and instructions, did what I needed with choke and the other buttons, put a small amount of unleaded in and after a couple of tugs on the string, she fired up.

So today I did the same thing and it just won't start. I here a few quiet "bub bub bubs" as I pulled and then nothing and no hint of something catching and it starting to go on its own. I added a little more petrol but still nothing. Fuel VALVE (not pump - sorry for the confusion) is open.

So I know most people here know more about cars and engines than I do (ok its not a car but its some kind of "simple" petrol engine) so I would think your guesses as to what is wrong are likely to be far more accurate than mine. So any ideas of what I can try?

Edited by mike42 on Wednesday 25th January 00:05

[normalbloke]

I assume 4 stroke? What fuel did you put in it?

[jamei303]

Did you try and start it in eco mode?

[Shuff4]

What position is the choke and fuel tap in?

[Ityre]

Start with the simple stuff, fuel level ok?, is there a small fuel filter ? If so may require blown through with compressed air or cleaned , could any water or condensation have got in the fuel, usually in something so new it will be a fuel issue. Alternatively is it connected to a load when you start it? Disconnect it first and then try , best of luck.

[Chumley.mouse]

Start with the simplest thing first, When I try and start disc cutter,chainsaw, whacker in the depths of winter they are all , almost impossible to start when they are stone cold ( for months ). Under normal conditions they all start fine. Pop it in the house overnight . Worth a try ?

[paulwirral]

Try removing the spark plug , give it a quick clean with a wire brush and heat it up with a naked flame then replace and try , it’s always worked for me , even on reluctant alpha twin cams of old !

[Matt Harper]

I'm surprised that a cheap generator has a fuel pump. Vast majority are gravity fed.

If it isn't firing, it has to be fuel or magneto related, but also check to establish if it has a low oil sensor/cut-out. If equipped that device cuts the magneto supply if it senses low/no oil. Cheap ones can be very hit and miss.

So, I'd whip the spark plug out and ground it to see if it sparks when you yank the pull-cord. If it does, you have a fuel issue.

Disconnect the fuel hose from the carb. With the fuel spigot open, you should have fuel dribbling out. Assuming you do, then the issue is inside the carb. These are dead simple components, that are easy to dismantle and reassemble. As suggested earlier, blow it through with compressed air - but also check the float in the bowl in the bottom of the carburetor. The float pivots on a small rod and if it gets stuck at either end of its travel, it will cut-off the fuel delivery to the jet in the inlet throat.

Or - you could just take it back to Screwfix and ask for a refund/new generator....

[anonymous-user]

Get some of this

https://amzn.eu/d/eWuWIVh

[finlo]

When you do get it going and want to stop it do so by shutting the fuel off and letting the carb run dry.

Petrol seems to go off more readily in the carb than the tank.

[OutInTheShed]

Back to basics.
Is there a spark?
Is fuel getting near the plug?

In my experience of small engines, like outboards, mowers, generators, small motorbikes....
9 times out of 10 if it won't start, then cleaning the carb is worth considering.
Small engines tend to have very small carb jets which easily gum up when the motor is not used.

Draining the carb if you are not going to run it in the next week or so may be wise.


Take the plug out. Is it wet?
connect the plug lead, rest the plug on the head and pull the starter. IS there a spark.
Just turning it over like this may get more air through the carb, hence move some petrol.

If you can remove the float bowl, check for dirt and water, check petrol was getting that far, spray the jets etc with carb cleaner...
Re-assemble and it may go.

[HustleRussell]

A guy in the race club was red in the face trying to get a nearly new generator going. I went over and he'd opened the fuel tap and closed the choke but he'd forgotten to set the electrical cutoff switch to 'on'

[rfisher]

Having recently spent £1k, not on lunch, but on a genny and arctic cable in prepping for the media frenzy promised power cuts, I can help.

1. Use the best fully synthetic 5W 30 oil you can get your hands on.
2. Use only Esso Supreme+ 99 petrol, or racing fuel.

Any ethanol will fk up your genny in minutes, whilst saving the planet.

If we don't get any power cuts this winter, there will be trouble.

By email obviously .

[normalbloke]

rfisher said:

Having recently spent £1k, not on lunch, but on a genny and arctic cable in prepping for the media frenzy promised power cuts, I can help.

1. Use the best fully synthetic 5W 30 oil you can get your hands on.
2. Use only Esso Supreme+ 99 petrol, or racing fuel.

Any ethanol will fk up your genny in minutes, whilst saving the planet.

If we don't get any power cuts this winter, there will be trouble.

By email obviously .

Aspen fuel.

[GliderRider]

Assuming you have a spark, take the air cleaner assembly off and put a few drops of fresh fuel straight down the carburettor venturi and without putting the choke on, give it a pull on the starter. If it fires and stops, the likelihood is water in the fuel. Ethanol is hygroscopic, i.e. it attracts water, and with the rapid changes of temperature we've had in the last month or so there has been a lot of moisure in the air and condensation.

The reason rfisher is recommending Esso Supreme+99 petrol is that it although they have to declare that it contains up to 5% ethanol, in many cases it does not contain any.

Edited by GliderRider on Tuesday 24th January 19:45

[mike42]

Firstly many thanks indeed for so many helpful replies.

Before I had a chance to read them, I noticed a small bolt at the bottom of the carb and wondered if that was to drain it. So I loosened it and sure enough a good half cupful of petrol came out. I've no idea if that is what people mean by the carb being flooded.

So now I've read what I should be doing (instead of randomly undoing bolts as above) I will first isolate the problem to spark or fuel by taking the plug out and seeing if there is a spark there and looking at the condition of it.

I could take it back to Screwfix and might still do but I think there is some value in fixing it myself (with your very kind help!) if I can: 1/ I don't lose tank of fuel and oil. 2/ I don't have to drive back to screwfix lugging the thing into the shop. 3/ Its likely to happen again so would be good to know how to maintain it long term. 4/ I might learn something.

[CharlesElliott]

The bolt at the bottom of the carb is to drain it, but the bottom of the carb should have petrol in it - that's normal.

[anonymous-user]

Assuming it was working and now it’s not, how did you switch it off, does it have a kill switch and have you turned it back to “on” ?

[Caddyshack]

My first guess is using the new rubbish petrol has messed up the carb. Most say to use the super rated stuff.

My PA bought a new lawnmower, she used the new fuel and after one use the fuel had eaten through the carb gaskets to the point that it would never start again until we replaced most of the carb parts.


But, I agree…check spark. Easy start in the air filter but you may need to clean out the carb with proper carb cleaner - nothing water based and inspect the filters, diaphragms and gaskets if you have used the rubbish fuel….also the jets will need blasting out with carb cleaner.

[anonymous-user]

On the other hand, I leave my mower with E10 in it all winter and it’s never not started come spring.