Ok, I have had this mower for a while and I have also had this trouble for a while and I can't seem to solve it.
This is the engine with th plastic carburettor, membrane and air vane dual spring governor.
It starts and runs but it is very sensitive to pushing and pulling (mowing!) motion.
As soon as direction is changed from pushing to pulling, the engine revs drop off, it stutters a bit, I see some puffs of black smoke and then it picks up again.
Sometimes it will just die off completely.
Often, when just standing there running, the revs will suddenly also drop off, the governor will try to compensate, I see the puff of black smoke end then it picks up again.
Here are my repairs / findings so far:
1) Replace diaphragm kit + clean out everything. NO CHANGE
2) Discovered cracked plastic intake manifold pipe. Replaced. NO CHANGE (!)
3) Fiddled with governor springs on many occasions. NO CHANGE
4) Replaced plug various time. NO CHANGE
Have found that if I manually force the throttle flap closed fully (on the carb itself), the revs do not really go down to an idle sort of speed. How low shoudl the revs go when doing this?
If I let it run a bit and then suddenly force the trottle on the carb open, it splutters and puffs black smoke before revving up. If I then repeat this, it will rev without spluttering until I leave it for a while again.
There are no other adjustments on this thing so I don't know what else I can try.
Perhaps someone here can guide me in the right direction on how to find the cause of this problem?
Regards
Bernt
#2
ILENGINE
How fresh is the fuel. if it is any thing like the crappy gas we have in the U.S., I have had gas that the owner claims he bought the day before that I would put in a small container and can't light it with a match.
How fresh is the fuel. if it is any thing like the crappy gas we have in the U.S., I have had gas that the owner claims he bought the day before that I would put in a small container and can't light it with a match.
You said that you had to replace the intake manifold tube? I had one with the same problem that you are describing. My solution to my problem was the valves needed lapping. What had happened was the crack in the intake had been letting small particles get in and started eating my valve seats. I did a valve job and it corrected my problem. Hopefully this will help you.
