MacAllister MLMP575SP46 Key Start Lawnmower - Starting Issue On First Starts

[The Tinkerer]

Hi!
Just thought it could be worth asking to see if anyone has any suggestions on a starting issue with my neighbours MacAllister MLMP575SP46 key start lawnmower which has owned from new and working perfectly until May.

Fast forward 2 weeks, when he went to start it the blade would only turn a fraction and stop, almost like the battery was flat and doesn't have enough power to turn it over.

I disconnected the spark plug, held the start lever, tilted the lawnmower on its side and turned the blade half a turn clockwise to see if it felt free, which it did, then tried to start it again and it started first time, even after emptying the bag a few times.

Then after the mower has been sitting in his shed for 2 weeks, the problem comes back again.

Is it likely to be a starter motor problem? if so are they serviceable?

[Mick]

Hi The Tinkerer, and welcome to TGMForum.

If I'm correct this machine has a Briggs and Stratton InStart engine fitted.  Depending how old it is, it's possibly in need of a wiring harness. There was an issue on the early  InStart engines which would cause this fault. it will just keep clonking repeatedly when you push the start button or turn key etc..

The other thing that can cause it is if something is stuck jamming the blade, or if something else is making the engine stiff to turn, it can have the same symptoms as above.

If you look at the back righthand side of the engine, if you see a white wire connector there then it will have the old loom on it.

Here's what to look for. https://thegardenmachineryforum.co.uk/index.php?msg=2291

[The Tinkerer]

Hi Mick, Thanks for the welcome and reply,

I looked at a few videos showing the starting problems but they all seem to be constantly clicking, this mower seems to turn for a second and then stop altogether, when releasing the key you hear the starter unwind again.

We found out that when its cold, if you take the spark plug out and turn the engine over for a second then put the spark plug back in, it will start.

If it was the battery or the starter, would it only happen on the cold start and be fine for multiple warm starts until the next cold start?