OutdoorKing Repair Forum Forums Repairs and Maintenance Questions on Engines Questions On Briggs & Stratton Engines Mower has failed to proceed

My 20+ year old B&S 3hp fitted to a Scott Bonnar reel mower will not start.
She is nowhere near starting!
Petrol seems to be getting through and I don't think there's a spark, but haven't had time to look properly.
My question is a bit generic but as its attached to a Scott Bonnar that you cant just lift and put in the boot to go to the mower shop I was wondering if there is any common electrical fault it might be, and roughly how much it would cost?
Also how much would it cost to just replace the whole engine as I would need to unbolt it anyway to take it to the mower shop minus the mower, and it is 20+ years old and does puff a bit of smoke.
I'm hedging over the pick up cost they would charge plus repair on a 20+ year old versus just replacing brand new, that I can fit myself

Kempe, unless your engine has been butchered in some way by a previous owner, it should be easily fixable. Briggs engines are notably reluctant to quit, and easy to repair.

Just begin by testing the spark. Remove the spark plug, re-attach the high tension lead to the top of the plug after removal, and hold the metal body of the plug against a bare metal part of the mower (usually the cylinder head). With the speed control in the start position, pull the starter briskly, watching for a series of blue sparks across the contacts at the opposite end of the plug from the high tension lead. If there are sparks, the problem is not ignition. If there are no sparks, tell us and we'll talk about next steps.

The only thing likely to threaten the viability of your engine is the exhaust smoke you spoke of, not trivial stuff like failure to start. The trivial stuff we can sort out in a flash.

Cheers Grumpy, had another look now its getting dark, and there is definitely no spark
Electrical stuff is not my strong point so a walk through some diagnosing would be appreciated.

We need the Model, Type and Code numbers stamped into the cooling air cowl of that Briggs engine, Kempe. Then we can see exactly what ignition system it has. Once we know that, a specific diagnostic process should be easy to work out.

Hi Kempe, and a warm welcome back to the forum.

I had a similar problem with my Briggs many years ago, it just became unreliable; would not start when I wanted to go mowing, was blowing a bit of smoke....not a lot...but enough to worry me...I bit the bullet and re-engined the machine with a G100 2.5HP. Honda and never looked back!
Briggs and Stratton are a good engine to work on, but when getting to the end of their working life can be pernickety and unreliable....the hard part is realizing when that time is reached.

all good advice as always , most times as grumpy said it is an easy fix but also is its time up ? the honda is a fantastic swap for easy of starting AND reliabilty . depends on if you like to keep it all as was meant to be ?
sometimes a good oil change helps a lot too as old oil tends to turn into smoke fast . and again an offer of help if your not too far away ? south aus' is a big place but a good idea is try yourself first , if help is needed then you found the right place
Dave

vccomm, I see Kempe is in Adelaide somewhere, so he may be within striking distance of you, 50 km or so.

Kempe, if you post the details of your Model, Type and Code, plus a picture or two of your mower, it will be easier to talk about your options. I agree that repowering with a premium engine, such as an OHV Honda, will make your mower sweeter to use, but it will no longer be original. Repowering with a piece of excrement, such as several engines I can think of, may make it less convenient to use than it is now, as well as losing its collector value. Other engines range between these extremes.

I have some difficulty in believing that anyone would wear out a Briggs engine by using it on a light duty cylinder mower such as an SB45: it takes several hundred hours of use, unless it is run for a long time in a neglected state. More likely your engine needs a tune-up.

Lets go the DIY route
The numbers are 82232 4016 01 92062403

Your engine was made on 24 June, 1992. I don't think SB45s were being made by then so I think it may be a replacement, but what we need are pictures of your mower, so we can see how the engine and mower match each other.

Here is the Illustrated Parts List:
http://bsintek.basco.com/BriggsDocumentDisplay/Z6ntACVJ1DajI.pdf

Here is the Operator's Manual:
http://bsintek.basco.com/BriggsDocumentDisplay/flivAJX-nfBhU7y.pdf

The most important piece of information right now, is that it was made later than 1982 so it has Magnetron electronic ignition, not breaker points. This simplifies finding out why it has no spark. In most cases where a Magnetron ignition system stops working, the problem is not in the module, but in the kill wire circuit. This is the system for shutting down the engine. There will be a thin black wire coming out of the Magnetron module, and running to the governor plate near the carburetor. We need to disconnect this wire at the module, then repeat the spark test. If there is no spark when the kill wire is completely disconnected, right at its source (the module), there are only two remaining alternatives: defective grounding of the module, or a failed Magnetron module. So, to disconnect the kill wire from the module you need to remove the cooling air cowl, complete with pull-start. You will then see the module close to the outside of the flywheel, with the high tension lead from the spark plug running directly to it. Find the thin black kill wire running to it, and disconnect the slide-on connector at the module. Now remember: with the kill wire disconnected, you have no normal safe way to stop the engine, so you can only test for spark by looking at the gap on the spark plug as previously. You can rotate the flywheel with an electric drill, or temporarily reinstall the cowl and starter. Please report whether there is spark when you make this test.

My machine is a Diplomat (prefer the rear catcher} and it is a replacement engine that I got fitted back then
Will do the testing over the weekend and report back.

Had a go this morning and ran straight into a problem removing the cowling, I only have metric spanners and socket set and the bolt at the top is not metric, tried vice grips but it is solid. (the one partially hidden by the spark plug cable in the photo)
Did manage to remove some cowling that bends round the front and side and I can see wires that looks like what is in the troubleshooting.
Is the 2 wires seen in the photo the kill wire I pull?
Sorry if tinypic is the wrong way to upload

Kempe, this is heading toward disaster. If you and I both went crazy, and the next thing that happened was you pulled off that wire, you then would have no way to put it back on. That is simply nutty behaviour.

Side valve Briggs engines have inch size nuts, bolts, and threads. You can't service the engine, let alone repair it, without having access to the required tools.

even a cheapy set will do the job , most places have tools that will do the job for maybe $70 . please dont damage anything , it just makes it harder as always , pm me if you need help . im out north a little but mostly around port adel'if all you need is help ?

Kempe, vccomm is experienced and very effective at sorting out problems with small engines. I suggest you make his acquaintance - you are fortunate to live near someone who is both capable, and generous with his help. To me, there seems to be no excuse for messing up your engine rather than contacting him.

Hi Kempe, both vccomm and grumpy have given you excellent advice....I have seen at the auto shops (Auto-One, Supacheap etc.) sometimes on special, tool-kits with both SAE...A/F (Inch sizes) and Metric sockets and spanners at very reasonable prices...also check online.