Mountfield Electric Start Gone Rogue – Advice Needed

[Sherlock121]

Hi all, hoping someone here can help.


I’ve got a Mountfield petrol mower with electric start, model SP46LS, and lately it’s started doing something weird — it will start itself without me pressing the start button. At first I thought the switch was faulty, but even with it completely disconnected, the mower still fires up as soon as I pull the handle.


Wouldn’t be a huge deal, except it’s killing the battery really quickly. I’ve stripped it down as much as I can to check for obvious stuff like dodgy wires, but couldn’t see anything.


There is a relay under the battery that looks a bit suspect (possibly burnt? the 2 chips in the middle? — see pic). Could that be the culprit? I’m hopeless with electronics, and the part is £150+, so I’d rather be sure before replacing it.


Cheers for any advice!

 

[jj4091]

There is no doubt that part is faulty and needs replacing. The question is why it has failed I am not familiar with that model but I would imagine if that is a relay then it will operate the starter solenoid. If that is faulty then that may be the cause of the relay failing.
Do a search on youtube for "Mountfield SP46LS starting problems" where you may find the answer. Other than that an auto electrician or Mountfield service supplier is probably the best person to look at it before you start throwing parts at it.

 

[Sherlock121]

Thanks for the advise i got in touch with mountfield and they have changed that entire part it appears to be built into the battery now so maybe there's a known fault