Honda GVX160 problem(non-boaty)

[PetiteFleur]

I've aquired a lawn mower from a friend who's downsizing. It's fitted with a Honda GVX160 petrol engine, 5.5HP. It had not been run since last year and then stored in a shed. I topped up the fuel tank & checked the oil level. It starts easily but only runs for about 3 minutes before spluttering & stopping. If you wait 2 minutes it again starts and runs for three minutes etc etc.
I've come to the conclusion it is a fuel/carb problem so I've cleaned out the fuel tank & fuel flows readily from the tank; I've stripped the carb 3 times, dismantled as much as possible and soaked in Carb Cleaner. Fuel still in the carb bowl after stopping. Checked the plug(but not changed it), and still it happens. The tank has a filter in it but it cannot be removed and in any case fuel flows easily. I've removed the air filter and still it happens.

I'm reluctant to take it to a dealer so turned to this forum for any suggestions. I'm a fan of Honda engines but this one has me flummoxed. Any suggestions?

 

[sarabande]

blocked air hole (tiny) in the filler cap would be a first suggestion, but if fuel flows freely ? If you take off the fuel line at a point downstream of the tap, does it flow till the tank is empty, or stop and dribble after a while ?

 

[PetiteFleur]

blocked air hole (tiny) in the filler cap would be a first suggestion, but if fuel flows freely ? If you take off the fuel line at a point downstream of the tap, does it flow till the tank is empty, or stop and dribble after a while ?

This morning I removed the tank, flushed it out with petrol and then half filled it and drained it back into the can and it flowed freely until emptied - but thinking about this, can the hose have delaminated internally?..... but the fuel flow when running must be tiny so I doubt it - also blew thro' the hose.

 

[VicS]

Well worth checking the fuel hose. It would be silly to get caught out by something like that. ( Edit: You have !)

It sounds a bit like a fuel flow problem. Runs until level in carb drops to the point where it stops and wont start again straight away 'cos there's not enough fuel in the carb.
Allow to stand for a few minutes ... carb slowly refills then it starts again.


Apparently no problem with the flow from the tank to the carb ... therefore look at the inlet to the carb. Filter there by any chance?
Needle valve blocked or not opening?... float sticking ?

Some carbs, when fitted with a soft tipped needle, have a small clip that links the needle to the float arm .. so that when the float drops it pulls the needle off its seat

BUT before going to deeply into it make sure you do have a good spark. CD ignition I guess so expect a spark that will jump best part of a cm. It'd be silly to keep pulling the carb if there's no spark.

A new plug would eliminate that as a cause

You call it GVX160 ... did you mean GXV160 ?

Parts diagrams at http://www.boats.net/parts/search/Honda/parts.html but you'll need abit more info to find the right one.

May also find owners manual if required at http://engines.honda.com/parts-and-support/