John Deere mower won’t run

[Harleyboy]

Hi, not sure this qualifies for this section but here goes:

JD ride in with 19.5 single cylinder Briggs and Stratton engine. Spluttered to a halt. Has fuel and spark but noticed a breather pipe half broken. Couldn’t see it in the garden but could have been chopped up. Anyway slightly bodged a repair as can’t find a new one but it still doesn’t run. Fuel to carb is fine and have tried a spare carb from sale engine on a defunct spares mower but no luck.

Any thoughts here?

Thanks

[jfdi]

Remove air filter, squirt of carb cleaner or brake cleaner down the carb then immediately try to start. No sign of starting then probably a spark issue, starts then stops then it's a fuel issue.

[LandieMark]

Breather pipe could be the vacuum to the fuel pump, so will need fixing properly.

[Harleyboy]

Thanks. Will try both although not sure I have brake cleaner. Pretty sure the bodge/repair pipe is sealed but will double check that.

[stevieturbo]

Harleyboy said:

Thanks. Will try both although not sure I have brake cleaner. Pretty sure the bodge/repair pipe is sealed but will double check that.

brake cleaner, easy start, etc etc Some form of fuel

[Harleyboy]

Still won’t run. Won’t fire/run on carb cleaner sprayed in directly. Has strong spark at the plug. Seems
To have compression as it blew out unburnt fuel with plug out.

Not sure what else to try?

[Steviesam]

Probably no help at all, but my old MTD wouldn't run. Tried everything and it turns out it was sucking air in around the carb to engine gasket. New gasket and tightened up and seems OK now.

[LandieMark]

Can the valves be adjusted? It may not have enough compression to fire.

[stevieturbo]

Harleyboy said:

Still won’t run. Won’t fire/run on carb cleaner sprayed in directly. Has strong spark at the plug. Seems
To have compression as it blew out unburnt fuel with plug out.

Not sure what else to try?

So it's heavily flooded ? Try a new plug.

Can't say I've ever done a compression test on a lawnmower, but it would make some sense to try. Instead of just guessing

[jfdi]

I picked up a very rough running self propelled mower. In fact didn't start at all when I first got it, new fuel cleaned out carb and it ran but only just. Sounded terrible and no real power. Thought it sounded like a car when the timing is way off. Turned out that is exactly what was up with it. The flywheel had broke the locating key and was about 15 degrees out from where it should have been. As the spark was triggered by magnets in the flywheel it caused the timing to be way out.

[Duratecbuh]

Is it the little Briggs intek motor?

If so... They are famous for snapping the compression release cam spring. Meaning it can never be started, as it can't overcome the initial cylinder pressure to get up and running .

Obviously might not be your problem, but is a well documented one nonetheless.

It's not a terrible job, I had to do it on mine.

If you Google intek compression release, I'm sure there's a plethora of vids on YouTube etc

Happy hunting

[Harleyboy]

Morning all, thanks for the suggestions. I ran out of skill and patience and called my mower guy. So, the problem was a snapped exhaust valve rod. Briggs and Stratton saved money by using steel rods for inlet and aluminium for exhaust. Who knew?

Luckily, I have a spare mower so was able to use the steel inlet rod and we have a fully functional mower again!

[LandieMark]

Good stuff. I thought it sounded valve related when it wouldn't fire on brake cleaner. I wasn't aware of the differing valve materials either.

[Harleyboy]

Yep, you called it!

[Polly Grigora]

LandieMark said:

Can the valves be adjusted? It may not have enough compression to fire.

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