Briggs and stratton quantum

[Andysp]

Hi I have a rover lawnmower with this engine.After priming it starts first pull but then dies out.If I keep giving the primer bulb a few presses while its dieing out it will keep going and after a few minutes it will run without help.To restart I have to prime again but it will keep running.I have sent for new primer bulb, do you think this is definitely the problem or could it be something else?

[tomlt]

Hi I have a rover lawnmower with this engine.After priming it starts first pull but then dies out.If I keep giving the primer bulb a few presses while its dieing out it will keep going and after a few minutes it will run without help.To restart I have to prime again but it will keep running.I have sent for new primer bulb, do you think this is definitely the problem or could it be something else?

I had Billy goat with this engine and had exactly the same issue, mine had a remote mounted primer (rather than on the carb). Anyway, mine turned out to be a bunged up Carb, not letting fuel through from the float chamber. A good strip, clean and carb service kit sorted it out.

[GardenKit]

All engines need a little extra fuel to start them, and this is what the primer does. Some need a little extra to keep them going whilst warming up, but the Quantum is not one of these whilst in good order. The problem with yours will be a partially blocked main jet not allowing sufficient fuel through. Although yo say it eventually runs without the primer pumps I doubt its running properly. In the first instance remove the bowl and clean it out, and clean the jet. The jet is the hole in the little brass bolt that holds the carb bowl on. Also drop the float out and clean the needle and seat. Change the fuel for fresh fuel and clean out the fuel tank, this should then do the trick. If not a complete carb clean will be required, best done in an ultra sonic cleaner. 

[Andysp]

Thank you for replies.I will clean the carb and see if that fixes it.

[spudulike]

Just to add to Gardenkits post and knowing he knows his lawnmowers - clean the jet with solvent and or airline, no drills or metal bits up there please!

[GardenKit]

12 hours ago, spudulike said:

Just to add to Gardenkits post and knowing he knows his lawnmowers - clean the jet with solvent and or airline, no drills or metal bits up there please!

To be honest Spud, its really fine to prick out the jets on these larger carbs with a wire. In fact Honda supply a set of picks specifically for this job.

I have the Honda picks which are merely two different diameters of  greatly overpriced steel wire, and have supplemented them with various other made from governor springs with the hooks cut off.

Often, the deposits in the jet holes and the holes in the emulsification tube can be a little stubborn and air or solvents will simply not shift it so a quick rodding with the wire is the best course.

I have even resorted to my set of acetylene torch nozzle cleaners from time to time, but these are like little files and need to be used very gently.

 

However, I never use these tools on two stroke carbs, only solvents or Ultrasonic and only ever use air with extreme care.3

Edited March 25, 2018 by GardenKit

[Andysp]

Cleaned the carb and its running perfect thank you all.If using an ultrasonic cleaner what cleaner do you put in it.

[GardenKit]

56 minutes ago, Andysp said:

Cleaned the carb and its running perfect thank you all.If using an ultrasonic cleaner what cleaner do you put in it.

Glad you got it sorted Andy.

Not sure what fluid I am using in my Ultrasonic at the moment, but its a proprietary one bought through one of my suppliers, probably Kramp.

There are two basic types, one for steels and glass etc, and another non caustic one for softer metals. Its the latter type you need for carbs.

The Ultrasonic will work with just water, but a bit of help from a cleaning agent is useful. In the absence of a proprietary fluid a drop of washing up liquid will help.