OutdoorKing Repair Forum Forums Repairs and Maintenance Questions on Engines Questions On Honda Engines Honda GCV160 Won't Idle

I have a 2 month old Honda GCV160 (Victa Mower) and yesterday I mowed the back yard, ran excellent like always, stopped it to have a rest (middle of day, stinking hot) and then went to mow the front yard. The mower all of a sudden no longer likes to be on slow setting and will just die. Still seems to run fine on fast but anything below fine it just stops.

* Mower starts fine
* I have checked air filter and spark plug, both fine.

Hi Alan, welcome to Outdoorking.

What happens if you increase the idle speed setting? If it just will not run below almost full speed (3,000 rpm), we get one solution, whereas if it will run at idle speed (2,000 rpm) but needs more throttle to achieve that speed, we get another one.

If it simply will not run slowly but is fine otherwise, my first guess as to what has happened is that the idle jet is blocked. It is only 0.35 mm diameter, and if you have been less than scrupulously clean in your refuelling operations, this might be the outcome. Here is a previous thread on the subject:

https://www.outdoorking-forum.com.au/forum/u...p;Words=gcv160&Search=true#Post38602

That engine had a more severe case of dirt-in-the-fuel than yours, so it had lean mixture symptoms as well as a blocked idle jet. Yours should be easier to fix, since there is a good chance it just has one simple problem.

Please continue this thread, keeping us posted on what you find - we are here to help, and every thread should end with a solution.

Thanks, I came accross that topic later on. I have the same engine by the looks of it with the same linkage/carby. I'll let you know how I go, thanks.

Yes, it is exactly the same engine, a GCV160, so following what was discussed in that thread should get you where you need to go. Please tell us what happens though, and if you strike any kind of difficulty, just say so and we can probably sort it out immediately.

i have 2 of these at home, and I think it may just be the throttle cable may need adjusting as if it has moved too much forward it can cause the choke to be out of alignment and also when the throttle is pulled back into lower revs tends to switch the mower off.

That's a good point, luvpsi, there are two different maladjustments that could cause this: the idle speed screw could be backed out, or the speed control cable could be maladjusted so that the kill switch operates with the speed control set at idle instead of across the detent, at stop. Just running through a normal tuning procedure would fix either of those faults, without dismantling anything. The mower should certainly be tuned before attacking the carburetor.

Finding out whether the idle cutting out problem is due to maladjustment of the speed control cable should be the work of a moment: just remove the spark plug, attach it to the plug lead, hold it against a bare metal part of the engine, set the speed control in the idle position, and pull the starter. If there is no spark across the spark plug gap, the kill switch is operating and the speed control cable needs to be adjusted. If there is a spark, the problem must be one of three things (in order of how easy it is to check them):
1. Idle speed screw set too low. Wind the screw halfway in or slightly more, and see if it will then "idle" (at about maximum engine speed). If it will, back off the idle speed screw and see how slowly it can run. If it runs perfectly well at the specified idle speed of 1700 RPM, the problem was just a maladjusted idle speed screw. If it dies when you try to slow it down to idle speed, consider possibilities 2 and 3.
2. Idle jet or passage obstructed by dirt. Clean the carburetor, following the method set out in detail in the previous thread referenced above. As part of the same exercise, check for intake leaks at the carburetor insulator gaskets. If you do this job properly and the problem still exists, we are left with the least likely, and most inconvenient, possibility.
3. Internal engine problem. We can discuss this if necessary, after eliminating possibilities 1 & 2. The first question I will ask, is whether the engine still develops full power when mowing with the speed control set to High.