OutdoorKing Repair Forum Forums Repairs and Maintenance Questions on Engines Questions On Briggs & Stratton Engines Mower sounds like it's exploding

The mower is a Rover Quattro 40 which has a Briggs and Stratton engine. It hasn't been used for a couple of months and the carby needs a clean. I tipped a little petrol into the spark plug hole and it starts but it revs loud and fast like it's going to explode and then stops because the petrol has run out. The starter cord is tangled up and I have to take the top off the mower and release the cord. I reassemble the mower put some petrol into the spark plug hole and the same thing happens again. I assume the governor needs adjustment but could there be another explanation and why is the starter cord binding?

Hi tiger. The best place to start would be a few pictures of your machine, if that's possible. Also the model type and code may be needed to correctly identify the engine. When you said 'reassembled' the engine, did you clean carby like you mentioned before, if not I'll go overit quickly.

You have already diagnosed that it is a fuel issue, by putting some fuel into the cylinder. If you have a pulsa prime carby, firstly start by taking fuel tank and carby assembly off the machine, strip, clean and flush, and replace diaphram and gasket with a new one. This is should fix the fuel issue.

As for the over revving, it is super common on that machine that the governor/throttle plate gets bent. This will either loosen the spring and thus make the engine run at very low rpm's. Or it can bend the other way and put tension on the governor spring, this may have happened to you. Inspect the tabs for any bending, and operate the throttle (when engine is off), and look at the governor spring.

As for the starter cord, it's hard to tell you what's wrong, without a photo. It does sound like something is warped or binding. Make sure not to over tighten it. But we have a lot of knowledgable people here, so maybe they would know.

Good luck mate, I'm sure you will figure it out.

G'day James, haven't got to cleaning the carby just yet. Have got some pictures on another one of my posts as I had some governor issues once before. The noise is a squealing sound and from what i saw on youtube it might be the clutch on the starter.

Correct me if i'm wrong, but the Quattro 40 doesn't run a clutch starter, i thought it had a ball top, but again, i might be wrong.
Also over revving could be the governor, but a loose or cracked manifold will give you the same symptoms and also explain why it stalls after the fuel runs out. So just check these when you take the starter off before you start a strip down of the carb.

The quattro 40 came out with both the clutch and cup style starter.

Thanks Joe, i stand corrected.
Tiger, yes, the squealing is most probably the clutch.

The ones with the clutch, had a second metal cowl ontop of the starter cowling with a little plastic cover ontop, the ones using the cup had the big plastic cowling over the single starter cowling... I hope that makes sense

Thanks Joe and Ted, definitely clutch on mine but I've run into another problem, think I'll start another thread though.