Calling all engine bods.

[Flunky]

Dont know if you saw the prev post about my lawnmower. It is beyond repair. So I got a second hand one from a guy i know.

It all works, however, it revs intermitently and stops if the choke is not on. i have asked a friend and he says it may be the mixture screw. i have looked but i cannot see it. does anyone know where this would be ? It is a briggs and stratton engine if that helps.

[Flunky]

[pete10]

Go to this site    http://www.lawnmowerparts.co.uk/partfinder_home.asp. and search for your model . Will give good diagrams . Of the carb etc
 

[Larkshall]

If it revs and won't run without the choke it looks like a mixture problem. Check that the carburetter is clean, even a very small bit of dirt in the jet will cause problems. First thing to check is is there dirt or rust in the petrol tank, there is then check the jet.

[Mr Smith]

Agree with Larksall give the fuel system a good clean out you can buy a flushing fluid to do the job old petrol will congeal in the system if left in the system for a period of time other than that look at the carb diaphram for a split, when I bought my rotovator last year I had this problem and in my case it was the Carb diaphram, all Briggs&Stratton engines have a manufacturers plate which give you the machines ID , from the top they read, Model, Type, and Code these should be quoted when you order any parts, for more help do a google search and you will get the main B&S agent in Weston Super Mare quote the codes to him if you want a carb kit or any other spares for your machine :)

[Mr Smith]

www.briggsbits.co.uk

[Flunky]

many thanks to all who replied. I took the carb off yesterday and a friend had a look, all seems well. I will flush through the system as suggested, it was standing for a while so i feel this imay be the problem. Do you think there could be an electrical issue ?

[Mr Smith]

Flunky,
              I do not think that you have to go down that street, just take on board the advice given, if  it still does not fire up come back to the site  :)

[keef]

Make sure its got new petrol in it - ie not stuff thats been sitting in the tank for month's - old petrol can give grief. But I guess if you've flushed the tank then you've done this..

[Flunky]

Flunky,
              I do not think that you have to go down that street, just take on board the advice given, if  it still does not fire up come back to the site  :)

Taken on board Mr Smith. Fires up fine just doesnt run well, only runs on full choke. out it to any other speed it will stop.

[Pesky Wabbit]

Have you ever thought of buying a new machine instead of faffing around with second hand ones that don't work ?

Q: Why do people sell their old machines off ?
A: 'Cause they're rubbish &  don't work.

[Flunky]

Have you ever thought of buying a new machine instead of faffing around with second hand ones that don't work ?

Q: Why do people sell their old machines off ?
A: 'Cause they're rubbish &  don't work.

Thanks for your input.

Would love to buy new machine, small issue of cost and the fact that i want to learn how to fix them rather than just throw money at something. i got a landmaster 7hp rotivator which was "'Cause they're rubbish &  don't work" for £50 now up and running and rotivating at a rate of knots. Could of "thrown" money at it and bought one, but thought i would give it a go. Nothing wrong with trying to learn something new Mr Wabbit.

F.

[OllieC]

If I had the space or need for such machinery, I'd do exactly the same thing. In the old days, I always did all the work on my cars. 10 years ago you could still work on a 10 year old car. Sometimes it was frustrating and sometimes it hurt, but it was great fun and you normally got there in the end.

It's a challenge, it's fun, it's interesting and it saves money. Also, new machinery like this, of a good specification, still needs maintaining. Briggs & Stratton engines aren't meant to be disposable, they're meant to be repaired...

[Flunky]

If I had the space or need for such machinery, I'd do exactly the same thing. In the old days, I always did all the work on my cars. 10 years ago you could still work on a 10 year old car. Sometimes it was frustrating and sometimes it hurt, but it was great fun and you normally got there in the end.

It's a challenge, it's fun, it's interesting and it saves money. Also, new machinery like this, of a good specification, still needs maintaining. Briggs & Stratton engines aren't meant to be disposable, they're meant to be repaired...

Bang on Mr C. Cost me £15 to fix rotivator. The guy next to me offered me £150 for it. No way to sell its a beast, Briggs and Stratton as you say. Apart from anything else only ends up in a tip or worse. its fun to do it. Any way stop spamming my mower thread. LOL  ;D

[kenkew]

Flunky; Stick with it. you have one of the best engines in the world there.
I take it you've cleaned everything, including sparkplug/gapsize and fuel lines?
I don't think there's an inline filter on that one so consider fitting new fuel lines, not a big job and any accumulated dirt there will be gone with new lines.
Your choke forces extra fuel in so I'm guessing too much air. Is your air filter in place?
Take out the plug. Is it blackened? Does the engine belch out black smoke? Does it stuggle under heavy work?

[Pesky Wabbit]

You any good with E-types then ?

My neighbours' got one, when hes not out working, he spends every second of every day under the bonnet.
I've yet to see him in the driving seat.

Perhaps I should get him online and save him from divorce.  ;)

[Melbourne12]

many thanks to all who replied. I took the carb off yesterday and a friend had a look, all seems well. I will flush through the system as suggested, it was standing for a while so i feel this imay be the problem. Do you think there could be an electrical issue ?

Certainly not electrical.  The need to keep the choke on suggests an air leak between the carb and the engine. If the carb bolts straight on, check the gasket. If it feeds the engine through a rubber hose, check that the hose is still a tight fit and not cracked and perished.

The other possibility is that the air filter is missing, and so the mixture is too lean.