Kawasaki FH601V surging / loping at high rpm

s1283

Forum Newbie
Joined
Jun 8, 2020
Threads
1
Messages
2
I bought a well cared for JD 717a mini z Trak 48” mower last year. It’s old but it is in fantastic shape.
The motor is a 19hp Kawasaki FH601V It idles fantastic, and starts like a dream, but at full throttle and especially under load it lopes and seems to struggle to maintain high rpm.
When I bought it I went right through it and services it to the nines; airfilter, fuel filter, plugs, new oils and filters, new battery, cleaned and greased. Since then I put a tach on it and checked rpm. At idle it’s between 1450-1500, and 3400 at WOT at peak, but will pipe down to 2800. I know idle should be adjusted at the throttle plate closed at 1450, with the governor plate screw to 1550, and WOT governor plate to 3600rpm. I’m not going to mess with those settings until I get the rpm to stay consistent at WOT. Feels like fuel delivery. I checked and ensured my fuel pump is putting fuel out strong. It pumps like a mad man when cranked. Being it’s new I should hope it would. I have taken the carb off and cleaned what I can without pulling off the float bowl. I wasn’t interested in taking that apart for no reason. It doesn’t leak or burn oil. It’s a Nikki double barrel. I drilled the two little covers on the top that keep you out of the jet adjustments. I found that they are both at very different extremes of adjustment. Any idea what they are supposed to be set at before I start manually seeking the correct adjustment? I’ve seen only one other person even mention them in a video cleaning his 25hp version said his were set at 2 turns out. One of mine was at 2.5 the other was almost bottomed closed. I took them out and cleaned them and then set them both to 2.5 and it still lopes. Idk if I should just start at the beginning and close them and back them out slowly until it runs right? Any help would be appreciated. It’s been frustrating trying to find any information on this carburetor. Seems there are a few versions I keep running into and none seem to be mine.
 
Last edited:

s1283

Forum Newbie
Joined
Jun 8, 2020
Threads
1
Messages
2
So update. It’s back together and running well. Cleaning the high speed jets fixed the loping under high idle and load and after some playing with the mixture screws I think I set them somewhere between 2 to 2.5 turns out. Took the time with my handheld tach and adjusted hard idle governer idle and full throttle on the governed plate for a win. I was down 200rpm prior and I’m guessing I’ll notice a big difference in mowing quality. Will see how it mows next week, but it seems to be right.
 
Top