OutdoorKing Repair Forum Forums Repairs and Maintenance Questions On Ride On Mowers Questions On Cox Ride On Mower Frames Cox 11hp, what year model is it ?

If it took 3 minutes to fill a cup, it sounds as if something is restricting the flow: I'd expect much less than 1 minute. However, a GV400 probably does not use a cup of fuel in 3 minutes. It is important to do the test with the end of the hose raised up to the level of the carburetor fuel input fitting.

When you have a time to fill the cup that way, go back to before the fuel filter and repeat the test. Then try it before the fuel tap. Also see if removing the tank cap makes any difference. Finally, with the fuel hose connected to the carburetor through the accessories (fuel tap and filter), remove the carburetor float bowl and see how long it takes to fill the cup by allowing fuel to run out through the needle and seat, over the float, into the cup.

Did you do the ignition test I asked for (when the engine stops, immediately crank it with a spark plug connected to the plug lead and grounded to the engine)?

looks like i`ve found the problem.mower cut out after only 5 mins use today,did the spark test & has plenty of spark.noticed that the fuel filter was empty again so poured a cap full of petrol down the carby & it started straight away.

went & got 1/2 a meter of fuel line & connected it straight from the tank to the filter.filter filled in about 5 seconds,started first go & ran with no problems while i mowed the back yard.let it sit idling on about 1/2 revs while i did the whipper snipping & it ran until i turned it of,so it ran for about an hour all up.

took the fuel tap off & blew through it,there was definately a restriction in there which i was able to blow out.

so all seems good now,i`m one happy little mower but wondering why it would take so long for the mower to stop with the restriction in the tap ?

I notice you have had the mower run for everything from 45 minutes down to 5 minutes, with the time probably getting shorter as you continued to use the mower. It sounds as if the crud you had in the fuel tap was a floating mass rather than a genuine build-up of hard stuff stuck to the interior.

When you get a time-delay feature in a situation of engine cut-out, chances are it is either temperature sensitive (which will have some cause like ignition module failure, cooling system malfunction, exhaust blockage, or lack of exhaust tappet clearance) or time sensitive, in which case it will probably be a fuel system blockage. Because your engine was initially taking so long to cut out, I started off focusing on temperature sensitivity, but once we'd eliminated that, we were left with fuel system. If you had been getting short run-times earlier in the process, it would have made sense to do the time-to-fill-a-cup-with-fuel test sooner. Floating masses in the fuel system are tricky like that though: sometimes no problem at all, sometimes a severe blockage. In this case, the floating mass suddenly blocked the fuel tap almost completely, right after the first time you did the time-to-fill-the-cup test. That sustained rapid fuel flow during the test was all it took to solidify the floating mass into a more compact, more effective blockage.

You need to flush out the tank and its fittings thoroughly now you know there has been floating crud coming out of it.

thanks for all your help grumpy,will clean everything out tomorrow & see how things go when i mow again next week.

even thought i stripped the carby down & cleaned it last week do you think it would be wise to do it again ? the only things i didn`t clean last week were the tank & the fuel tap.how would you recommend to clean the fuel tank ?

cheers
jason

First, the fuel tank. Here are the disassembly and reassembly instructions from the manual:



You need to remove the starter, top cover, tank stay, then tank. It will probably be most convenient to disconnect the fuel line from the tank before you remove the tank stay.

The interior of the tank needs to be bone dry before you clean it. My method of cleaning is to start with compressed air, then brushes and rags to dislodge the recalcitrant stuff, then more compressed air. Ensure the interior of the outlet is clean.

Here are the carburetor cleaning instructions:


I have found it necessary with this style of carburetor to clean the interior with carburetor cleaner, squirting it through each jet, each emulsifier orifice, and each drilled passage, then blowing the residue out with compressed air. Only the cleaner will remove gum: blowing out, running oxy torch tip cleaners through, washing in petrol etc does not remove gum. If you did all of this thoroughly last week there is no need to do it again, but if you did not clean all of the orifices and all of the drillings with carb cleaner, you need to do it now. If you did a full clean last week, just drain the float bowl into a cup and inspect it for any foreign matter.

thanks again grumpy,will do as you have suggested above & report back next week after i have mowed again.

cheers jason

well i`m pleased to say after cleaning the tank & draining the fuel bowl on the carby & re assembling, the mower ran great when i did the lawns today.no stuttering,spluttering,losing revs or cutting out.it was run for just under an hour straight.

a bit thankyou to you grumpy for all your assistance & guidance.

cheers
jason

Thanks for letting us know the outcome, Jason. A story without an ending frustrates the readers. I hope the whole mower, and especially the GV400 Honda, provide many years of enjoyable mowing. If you have any questions in the future, just come back and tell us - solving problems is fun.

I'll close this thread. If anyone needs to post to it, just PM a moderator.