Problem with Petrol Mower - Mountfield SP414

Latest update, managed to get the spark plug removed. The head of this is black , is that a sign of a bad plug ? pardon me for being ignorant of this, it has been a very long time since I had to look at my car engine (back in the days of a Mini Clubman ). The model of this spark plug is a GGP K7RTC

** EDIT 22nd April 14:57**
Cleaned the head of the spark plug with a wire brush and got a good amount of it cleaned up. Put it back in and it first started up okayish and then stalled, repeated the cleaning process again and it is running for longer now but it still misfires every so often. Would this tend to indicate it is a spark plug problem ?


Thanks

TimCS

 

I have never used an air duster but should be ok.

Is the sparkplug dry and sooty as opposed to oily and sooty? If so I would go in the direction of too rich a mixture which could be caused by a restricted air filter or carb issues.
So either to much fuel or too little air.
It could also be the adjustment screws on the carb which adjust the mixture but dont jump in there until all other avenues have been looked at.

 

I would say that it was dry and sooty not oily and sooty.

The fuel was drained out before I removed the spark plug and only a small amount was added at the time as I did not want to put a lot into the tank in case I had to drain it again.

With regards the "air" issue, I have read the maintenance manual and it first states that the petrol cap should not be too tight to allow air in so I have tried that as well.

Is it worth me buying another new spark plug? as they are not too expensive anyway.

Also I have managed to mower the entire back and front garden now but I am unsure how long this will last as it still was "misfiring" during that time

I would like to ask the opinion of petrol mower brands as in which are the best for a home user but I do not want to stray from this thread so am I best posting a new question for that?

Thanks

TimCS

 

It's definitely worth buying a spark plug! Go to a lawnmower repair workshop or even a car parts shop (not a major retailer like Halfords as the plug will probaly cost more than a new mower ).

Take your old plug with you as as the part number may need cross-referrence and comparison if alternative brands are only available.

 

Looking at Halfords prices I do not think that they are that expensive!! If they were I think they would have stopped supplying them . they seem to range between £4 and £8 there, still what harm would it do to get them to give me a price and then see if I faint or not

Thanks

TimCS

 

You can also purchase on ebay £2.42 + free postage.
Despatched within 1 working day.

NGK SPARK PLUG to fit Mountfield K7RTC GGPK7RTC 1x Copper Plug (S6097) | eBay

 

Hi Scudo

Yes I did fine that page on ebay but would like to try and get a spark plug this weekend if possible first just to see if it is that but if I cannot find one, then I will probably get it from there.

Thanks

TimCS

 

Just an update, firstly my internet has been playing up so sorry for the delay, I have tried a new spark plug from the ebay re-seller and this has not really cured the issue.

The mower first started up and stalled , tried again and it seemed to keep running so I stopped it so that I could try and then cut the garden with it, started it again and I could hear it was not running evenly and during cutting the lawn it cut out again.

I would like to ask of the "budget" mowers under £200 are mountfield mowers ok ? I have been thinking on the other makes such as Qualcast and Ryobi

Thanks

TimCS

 

You may be able to get your mower serviced/repaired for a fraction of the cost of a new mower. Shop around for quotes.

If it's a write-off and you need a new one, here's a personal point of view:

Mountfield: Probably

Qualcast: Worth considering

Ryobi: Buy a prawn sandwhich instead. It will last longer and save you a fortune in the long term.

 

I agree with the above, if you are up for it I would see if they would just check over the carb for you if you can detach it from the lawn mower.
Another option ...do you have any neighbours that are in to DIY repairs cars or bikes, by comparison lawn mower carbs are much simpler than cars or bikes.
I still think the issue is in the carbs.

If you are at the point of considering buying a new lawn mower then you have nothing to lose by taking the carb off and having a look.

 

Hi all

Thanks for the replies , interesting views on the models, so I get the impression that Ryobi are pretty useless then, seems incredible considering what they cost.

I am planning on getting another and keeping this mountfield as a back up once I get it sorted.

Sadly I do not know anyone local who knows about engines etc it was something I considering before but all those that I know have moved further away now.

I still want to get this working as a secondary mower and with my lawn it does need a petrol mower as I have tried electric ones and they cannot cope with it.

One other question, when putting a petrol mower away over winter, is it always best to drain petrol and oil ?

Thanks

TimCS

 

Oil I wouldnt bother. Petrol 2 avenues of thought on this, if you drain the tank then it can encourage the inside of the tank to corrode because damp air now fills the tank over winter (tank may have a coating to prevent corrosion though), if you leave the fuel in the tank it can go off although I believe you can add inhibitors (never used them). Definitely drain the carb, I just turned the fuel off and let the mower run until it emptied the carb and the motor cut out.

When I had a petrol mower I never drained the petrol or oil tank (same with motorbikes) and just turned off fuel and run the carbs dry. I am not saying I am correct but never had any issues doing that.

I assume you are not near to central scotland, otherwise I would see if I could fix it for you.

 

The engines for Mountfield mowers are now built in China. When I was shopping for a new mower a few years ago I was told by a trusted retailer not to buy one as the motors are cheaply built and unreliable.

 

I've never drained petrol from any of my mowers and not had a problem, Hayter and Sitga

 

@Scudo

Not sure how I would "turn the fuel off" to drain the carb on this model. Sadly not near Scotland , Derbyshire is where I am .

@Sheal

Interesting fact on Mountfield, makes sense to why it has behaved this way, are the Qualcast models better made do you know ?

@Jiffy

Sounds like you have better makes that I can afford With buying from Homebase I can knock £50 off the price with nectar points that is why I mentioned the models Qualcast and Ryobi but from what has been said here, Ryobi are useless. Anyone heard off the brand McCulloch ?

Thanks


TimCS