Mountfield Honda GVC135 engine problem.
 

Hello all,

My aged father bought one of these mowers on recommendation but after only a couple of seasons it is faulty.

It starts fine, runs for about 3 - 4 minutes then stalls - a classic symptom of fuel starvation. Leave it a few minutes and then it starts and runs for a similar period, then stops again. If you try and cut grass while it is running it seems to have no power as even short grass slows the engine - Fuel starvation again springs to mind as the mixture must be weak.

The carb has been stripped,cleaned and blown out with a high pressure airline and fuel changed, fuel pipes checked but to no avail.

Have any of you ever had this kind of fault before?

Please help, otherwise a perfectly good mower will be heading for the dump.

Fixed it!! In case anyone else has this problem - the vent hole in the fuel filler cap was BLOCKED. Mowed both lawns with no problems today.

I've got the same model. I had exactly the same problem and was about to enter an expensive round of repairs with a dealer 40 miles away. Tried your solution and hey presto it works. Well done and thanks for the fix.

Bad news - mower was dragged out last weekend having done last year successfully but now would not start.
Again I pulled the carb apart and blew out the jets. On reassembly it started first pull but only ran for some 15 seconds and then stopped. It will restart a few minutes later, on choke, and run for another 15 seconds and stop.

It seems the filler cap vent solution was a red herring.

I am convinced it is something to do with the vacuum control on the throttle rather than fuel delivery....

Anyone got any thoughts on this?

In case it helps other users in the future ....

Same problem here. Dies after a minute or so. Always restarts but then dies.

In my case I stripped it all down and eventually bought a new (expensive) ignition module which made no difference!!

Finally I bought a new spark plug giving an instant cure. It must have been breaking down electrically when hot.