engine hunting

[technic123]

I have a Briggs and Stratton quantum engine that hunts at full throttle

I have cleaned the carb and adjusted everything however the problem still occurs

Also there is a squealing noise from the driveshaft gearbox

Thanks

[Agi-Smash]

Hunting at top end? Sounds like one of the carb diaphragms. Available fron any good garden machinery place for about £4.

Squealing from shaft. Could be dry or have debris wrapped round the shaft or bearing.

[GardenKit]

A Quantum has no diaphragms in the carb, its the smaller Classic/Sprint engine that has the diaphragms.

The issue is a lack of fuel, or excess of air,causing a weak mix. A good ultrasonic clean may clear the jets. The idle mixture screw could also make a difference, even to top end mixture.

But it is not unusual to need a new carb if its a bit worn.

 

As for the screeching noise, first check the drive support bearing (bush) outside the engine, and the roll pins on the drive shaft tube.

 

If they are OK then the internal PTO drive gears are suspect, but not a common problem

[spudulike]

A Quantum has no diaphragms in the carb, its the smaller Classic/Sprint engine that has the diaphragms.

The issue is a lack of fuel, or excess of air,causing a weak mix. A good ultrasonic clean may clear the jets. The idle mixture screw could also make a difference, even to top end mixture.

But it is not unusual to need a new carb if its a bit worn.

 

As for the screeching noise, first check the drive support bearing (bush) outside the engine, and the roll pins on the drive shaft tube.

 

If they are OK then the internal PTO drive gears are suspect, but not a common problem

 

When they wrote that song, one went to mow a meadow, it was Barrie mowing that meadow - he da man on mowers:thumbup:

[Dean Lofthouse]

When they wrote that song, one went to mow a meadow, it was Barrie mowing that meadow - he da man on mowers:thumbup:

 

[technic123]

thanks for that

i have adjusted the screw at full throttle and it doesn't seem to make much difference

i have also cleaned the carb many times with carb cleaner and it hasn't made any difference

it seems to stop hunting after a good 10 mins of running so it may be a sticky governor or something

[GardenKit]

It will not be the governor at fault, its a carb issue. Its running a little weak, but if its Ok after 10 minutes then just put up with it.

[Agi-Smash]

Fair play Gardenquip. I bow to your superior knowledge.

Edited June 29, 2014 by Agi-Smash