[adal]

Last year my lawn mower wasn’t felling very well as it starts well and runs ok but as soon as you try to cut grass with it the power just drops and it seems hard for it to cut the grass.  As well being self drive it is a Mountfield Laser Delta 42 with a B&S 35 classic engine

[poohpouri]

Hi sorry i cant help but i have the same mower and mine has started doing the same so will keep a eye on this post

[Gwiz]

As a first port of call, Have you tipped the machine on it's side to clean underneath? If so, it's a fair bet the air filter is contaminated with engine oil so it'll be worth checking that, or it may just be very dirty.
The other common problem with these is that the carb diaphragm deteriorates over a period of time and will need replacing. They're not expensive.
If you have any more problems, just sing out, and let me know how you get on.

[BIG ZOOK]

If everything is as Gwiz suggested .and things still are runninng low on power .Remove the air filter and place a bit of bluetack between the carb body and governer arm ,so you raise the revs a little.Do not get it running like an F1 car .I have 4 mowers with the 35 engines in that i have used this way for yrs,first time starters and no excess oil comsumption,sounds shabby ,but it works.

[Gwiz]

I've done that myself while waiting for a different govenor spring to arrive

[BIG ZOOK]

I've done that myself while waiting for a different govenor spring to arrive

Some of my older 35 engines,seem to run the same govener spring configaration as the latest models ,but once warmed up  :)they do seem to run at fewer revs (emissions -maybe).However i`m a firm believer in the blue tack trick  .

[adal]

One update on lawnmower new diaphragm and it run’s like new thank you all for the information 

[Gwiz]

It's a pleasure to do "buisness with you"
If you'll just send me your address, and I'll stick my consultation fee in the post.....

[adal]

I live at the hotel California Such a lovely place

[compostqueen]

I wonder about mowers and whether they are fit for purpose.  My husband got the mower out today, big ride-one thing. It wouldn't start, so he gets out another one - a beast of a thing. It started up first crack, went a yard, backfired and stopped, never to re-start. So he gets out number 3. The string broke on that one so it was number 4, the littlest one of the lot. It started just fine and I mowed the grass with it while he tinkered, hammered, banged, swore, went shopping twice for bits, but had to put them all away again as it got too dark to see     Tomorrow I have to collect a new battery for the ride-on, go and find a spark plug for one and a replacement cord for the other    I suggested we chuck the lot and phone Green Thumb 

[Paul Plots]

The joys of a small lawn and a push mower eh? 

[compostqueen]

Oh absolutely 

OH has gone off today with spark plug in hand