Mower stalls on throttle

[Burnerman]

I have to admit, these rod linkages can be the work of the devil.....what you mustn't do is bend them with pliers!
Sometimes the links can be disengaged by removing the carb from its studs first, but on some machines the stud has to be unscrewed first - a right pain.
The answer to your problems will likely lurk within the float bowl, as that's where the fuel flow is regulated, and the jets that feed the engine. Therefore, that's the first bit to be removed!
John

 

[Hobsini]

Hi, carburettor now off, float bowl removed but can't get pin out to remove float. Is there a knack to that? Have cleaned up carb as best I can using carb cleaner etc. It was covered in dirt on the outside and not great inside but now much better although not perfect. I've seen some comments about soaking it but not sure what I'd need for that. Any other suggestions before I refit? Need to get float off first as well so I can check needle etc.

Knew nothing about carbs before trying this but have learnt a lot - thanks.

 

[Hobsini]

Mower now running - although have a further problem with the powered collector which I have posted under a separate thread.

Burnerman, many thanks for your help with this issue.

 

[Burnerman]

Apologies for missing your post concerning the float pin......more often than not the pin just pushes out, but I have met the odd one that was tapered and therefore could only push out one way.
Anyway, that seems to be in the past now so well done!
John

 

[Hobsini]

Having cleaned the carb and got it working:running properly things now seem to have gone backwards. It is now a real struggle to get the mower started. It turns over ok but won't start. Previously it started fine but stalled when more throttle was added. Now I can't get it to start - most of the time. On the occasions when I do finally get it to start it runs fine - although possibly excess smoke when running at full throttle. Is this the same problem or another one?

 

[Burnerman]

The motor is running too rich - and I'll bet the spark plug is black too. The first thing is to check the air filter, and then the choke linkage, in case the choke is partially on.
Try starting from cold without choke, and see what happens there.
John

 

[Hobsini]

Hi,

Still struggling with this issue. Mower now starts reasonably reliably but is definitely running too rich. It throws out a lot of smoke (often black) and seems to burn a lot of fuel. I have tried adjusting the carburettor fuel and idle speed pins but they don't seem to have made much (if any)?difference. I have replaced the spark plugs and the air filter (although not the sponge part). I am now stuck and although the mower runs it does not really run well. I have still not figured out how to get the PTO working either. Getting to be point where I might have to get it serviced after all!

 

[Burnerman]

Any carb adjustments only affect the slow running mixture as a rule....can you post a pic of the ones you have adjusted?
Are you sure the choke isn't partially on......that's the usual cause!
John

 

[Hobsini]

Thanks - will check.

Also, when cutting long grass would you expect the mower to struggle and chuck out more smoke? I have found it almost runs and cuts better when it is not set to full throttle. Occasionally, it also seems like the throttle setting makes no difference and the revs start to go through the roof. This only happens when the cutter is engaged and it tends to return to normal when disengaging the cutter.

Do the governor settings affect this and could I have impacted them by removing the carb?

 

[Burnerman]

When the machine is under load, the governor tries to get the engine to maintain it's speed by opening the throttle...if there is a choke issue then certainly the problems are as you describe, similarly when the cutters are engaged and particularly if the machine has an electric clutch on the cutter deck.
I'm afraid I can't tell if the governor has been upset but that's most unlikely so long as the linkages haven't been bent.
John

 

[Hobsini]

I don't think the linkages were bent at all when I removed the carb. However, that assumes they are the two relatively thick wires connected to the carb. There was also a third thin wire which runs alongside one of the thicker wires. This probably was put a bit out of shape by removing and replacing the carb. I am not sure what this does but I can't see how this could be moved without it being bent - a little at least.

Will post some pics of this and idle fuel/speed adjustment pins as soon as I can.

 

[lostinthelight]

Out of interest, do you have a separate choke control or is the choke operated by moving the throttle lever past the high speed position?
litl

 

[Hobsini]

There is a separate choke control at the side of the engine. You pull it out and it then (generally) returns to the normal position itself. I think the issue is definitely in this area e.g. choke/governor not working correctly in some way. Will post some pics of this when I get a chance but I think it might have to go in for a service!

 

[lostinthelight]

I think there may be something missing if you have to operate the choke from anywhere other than the driving seat or is it not a key start?
litl

 

[Burnerman]

Sure to be a key start, I think....my guess has to be the choke not coming off fully as the high speed running mixture isn't adjustable. These motors are also very sensitive to a blocked air filter.
John