Mountfield R28M Ride-on-Mower Mistake? Any tips..?

stuhse

His questions suggest he doesn't. 😀

ThisIsWeird

stuhse said:

His questions suggest he doesn't. 😀

C'mon! The guy's removed the rocker cover from his engine, a job very very few folk have done on theirs!

(Ok, he shouldn't have, but hey...)

Section62

ThisIsWeird said:

Engine Start will very likely get the thing going before the cleaned plug has a chance to be oiled again.

Engine Start will make the engine fire (if there is a spark), but it won't make the oil in the cylinder magically vanish.

The oil also won't magically disappear in the first combustion stroke, hence why we are all expecting lots of smoke in the first few minutes of the engine finally running.

During that time the extreme pressures and temperatures within the cylinder will be atomising some of the oil and doing its very best to get as deeply engrained in the spark plug insulator as it can.  Combustion of the oil on the surface of the insulator will likely take it outside its normal operating range and potentially cause microcracks which will lead to premature failure.

Essentially if you can avoid doing something which risks causing additional damage then it is a good idea to avoid it if you can.  Putting a brand new spark plug into an engine you know has excess oil in the cylinder is a bad idea.  Doing so before you know what other faults there may be with the engine (i.e. because you've just assumed the old spark plug is faulty) is even less wise.

ThisIsWeird said:

And, after the mower starts, and the smoke has cleared (I really hope he videos this...), a few minutes of burning-off the remaining engine oil won't, I don't believe, wreck the new plug in any way. It'll likely only end up having a light dusting of carbon on it, something it would gain after a couple of lawn-mowings in any case.

We have to agree to disagree on that.

sujsuj

Today is my final day of DIY on this because my Garden is worst that neighbour's field...I am going to trying everything mentioned here except blow torch ( as I don't have one..)
Make or Break day...Hopefully the first one

sujsuj

I can see choke symbol, checking manual to see how to put lever in that mode. Looks like just pushing to extreme lower position. let me look around..? Any inputs..?

ThisIsWeird

Section62 said:

ThisIsWeird said:

Engine Start will very likely get the thing going before the cleaned plug has a chance to be oiled again.

Engine Start will make the engine fire (if there is a spark), but it won't make the oil in the cylinder magically vanish.

The oil also won't magically disappear in the first combustion stroke, hence why we are all expecting lots of smoke in the first few minutes of the engine finally running.

During that time the extreme pressures and temperatures within the cylinder will be atomising some of the oil and doing its very best to get as deeply engrained in the spark plug insulator as it can.  Combustion of the oil on the surface of the insulator will likely take it outside its normal operating range and potentially cause microcracks which will lead to premature failure.

Essentially if you can avoid doing something which risks causing additional damage then it is a good idea to avoid it if you can.  Putting a brand new spark plug into an engine you know has excess oil in the cylinder is a bad idea.  Doing so before you know what other faults there may be with the engine (i.e. because you've just assumed the old spark plug is faulty) is even less wise.

ThisIsWeird said:

And, after the mower starts, and the smoke has cleared (I really hope he videos this...), a few minutes of burning-off the remaining engine oil won't, I don't believe, wreck the new plug in any way. It'll likely only end up having a light dusting of carbon on it, something it would gain after a couple of lawn-mowings in any case.

We have to agree to disagree on that.

'Microcracks' ma botty. Yes, we'll have to disagree! For the cost of a plug, I ain't going to entertain such extreme 'possible' scenarios. Coupled with the fact that SS has no suitable method of getting that old oiled and carbonised plug suitably clean.

If SS can get that darned engine to fire up with the new (solvent-cleaned) plug, then almost certainly the  whole issue will be fully resolved in a puff of smoke.

sujsuj

I can see old spark plug gave good spark.
1. I removed spark plug from engine
2. connected to the wire
3. Make its touching engine body for earthing
4. Tried to start engine.
5. Noticed Good spark

Is this means even old spark plug is completely OK..? See video.
Any new suggestions based on this..? Should i continue to use old spark plug..?

sujsuj

https://youtube.com/shorts/fq6Zm3V7jds

ThisIsWeird

sujsuj said:

I can see choke symbol, checking manual to see how to put lever in that mode. Looks like just pushing to extreme lower position. let me look around..? Any inputs..?

Good lawd, man. How have you been starting the darned mower up until now?!

Yes, that would appear to be it. The lever is pushed fully down to the 'choke' symbol for starting from cold. Isn't that what you normally do?

Once it fires, you pull the lever up to between the 'hare' - which is the engine's fastest running position - and the tortoise, which is the slowest (and where it should be left when it's not actually moving).

You have two choices...

First) Wash the new plug in petrol. Let it fully dry. TEST it for a spark as explained by S62. If necessary, set up your camera to be videoing it whilst you jump in the seat and crank the engine. See if it sparks. Then either:

1) Replace the plug, set throttle to 'choke', and crank away as before. Listen for at least a 'cough' from the engine. Give it a good half-dozen attempts of 5 seconds each. If nothing doing, remove the plug, look at it closely, see if it's glistening again, and sniff it - does it smell of petrol? It should. Clean it again, and replace it again. And try it again.

Or...

2) Get some 'engine start'. This time, do not set the lever to 'choke', but set it half-way between the two animals. Squirt a second of spray in to the air filter intake (no real need to remove it). Jump on quickly, and crank away. Give it just two attempts. If now't, jump off, and give it another second's spray. Jump on and crank.

Report back.

Bear in mind that if we find out you haven't turned the fuel 'ock back on, we will hunt you down. 

sujsuj

putting  lever to choke mode looks like this from outside. Inside lever cover and controls next to engine. Thanks