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I have about 32 hours on my new X738 and have a few concerns regarding the Kawasaki engine. I've always heard how smooth and reliable they are but I'm not so sure about the smooth part.

1) There seems to be quite a shake when starting or stopping the engine, almost like a loose/broken engine mount, but I don't see either. I start and stop at 1/2 throttle per the manual.
2) I have to advance the throttle lever almost 40% up the scale before the engine speed will increase at all.
3) At the lowest engine speed and slightly above that, the engine is not all that smooth with a fair amount of vibration. Nearing half throttle is getting a much better and 3/4 throttle and above it is fairly smooth with minimal vibration. Is this typical?
4) If I advance the throttle or pull it back too fast the engine wants miss or skip a beat and then the governor seems to correct and the speed settles into the throttle setting. If I change throttle position slowly either way this does not happen.
5) If I've been running full throttle (mowing) for a while then shut it down (from half throttle per manual) and attempt to restart several minutes later the engine will quickly fluctuate the rpm down then up as seen on the tachometer. Like its going to die but the governor takes over and brings the rpm back up to the throttle setting. This goes on for about 6 cycles then everything evens out and the engine runs properly. Seem like I can avoid this by letting the engine run at half throttle (as indicated on tach) for a few minutes before shutting it down.

With respect to items 3, 4 and 5 my dealer just tells me these engines are real tight when new and when I get past the break in period (50 hours or so) this stuff should sort out. He claims that items 1 and 2 are a normal characteristic. Not so sure I believe him. Would appreciate some input from other owners of these Kawasaki engines as to their experiences.
 

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I have about 32 hours on my new X738 and have a few concerns regarding the Kawasaki engine. I've always heard how smooth and reliable they are but I'm not so sure about the smooth part.

1) There seems to be quite a shake when starting or stopping the engine, almost like a loose/broken engine mount, but I don't see either. I start and stop at 1/2 throttle per the manual.
2) I have to advance the throttle lever almost 40% up the scale before the engine speed will increase at all.
3) At the lowest engine speed and slightly above that, the engine is not all that smooth with a fair amount of vibration. Nearing half throttle is getting a much better and 3/4 throttle and above it is fairly smooth with minimal vibration. Is this typical?
4) If I advance the throttle or pull it back too fast the engine wants miss or skip a beat and then the governor seems to correct and the speed settles into the throttle setting. If I change throttle position slowly either way this does not happen.
5) If I've been running full throttle (mowing) for a while then shut it down (from half throttle per manual) and attempt to restart several minutes later the engine will quickly fluctuate the rpm down then up as seen on the tachometer. Like its going to die but the governor takes over and brings the rpm back up to the throttle setting. This goes on for about 6 cycles then everything evens out and the engine runs properly. Seem like I can avoid this by letting the engine run at half throttle (as indicated on tach) for a few minutes before shutting it down.

With respect to items 3, 4 and 5 my dealer just tells me these engines are real tight when new and when I get past the break in period (50 hours or so) this stuff should sort out. He claims that items 1 and 2 are a normal characteristic. Not so sure I believe him. Would appreciate some input from other owners of these Kawasaki engines as to their experiences.
1. If the rubber motor mounts and attaching hardware a good your dealer is correct. Your tractor's engine is bigger than most motorcycles. That mess/mass of steel is going from a dead stop to 1,000 rpm in a few seconds. All that twisting energy has to go some place. Same thing when shutting it down. Solid steel mounts would stop most of it but would vibrate badly when running. If you think gas engines are bad try a diesel. Have your dealer start one next time you stop by.

2. Fairly normal. My X540 is similar. You pretty much only have 3 positions. Full, middle- 1/2 and idle.

3. Tractor engines are designed for full throttle operation. At idle they will shake more. Believe me that you want it to shake less when you are cutting grass (at full throttle). Plus for the most part you are only running the engine at idle for short periods of time. This may improve as the engine brakes in. Plus 50 hours is only a number JD came up with. In my opinion brake in takes longer than this.

4. When you slam the throttle open or shut this will happen. That's exactly what is happening. The governor is trying to play catch up to the sudden change. Move the throttle slowly unless it's an emergency. Also may improve with more engine hours.

5. Your engine is telling you what it likes. You want to let the engine idle a minute or so before shutting it down. This gives the engine time to cool down a little. Engines actually get hotter just after you shut them down. This is because your stopping the flow of coolant and oil. This is even more important with a turbocharged engine. The wheel inside keeps spinning for a long period of time after shutting down. Stopping it hot will cook the bearing that this wheel/impeller rides on. Letting the engine cool down will also make it last longer. Like over years of use.
Also try shutting it down from idle. That's what I do. The engine should also shake less because the internal parts are turning slower when you cut the key off.

Good luck
 

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Regarding the shaking at startup/shutdown: My x758 does the same thing. My guess has been that they have some fairly flexible engine mounts to keep vibrations down while in use so they flex while inertia is acting on things during start/stop.

The fact that your throttle isn't linear is odd, at least if the gas engine is normally anything like the diesel. My throttle changes instantly and linearly as I move the lever.

Rob
 

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Regarding the shaking at startup/shutdown: My x758 does the same thing. My guess has been that they have some fairly flexible engine mounts to keep vibrations down while in use so they flex while inertia is acting on things during start/stop.

The fact that your throttle isn't linear is odd, at least if the gas engine is normally anything like the diesel. My throttle changes instantly and linearly as I move the lever.

Rob
I agree with your statement I highlighted, Rob. There should be a consistent increase in engine speed with the movement of the throttle lever. If the OP's throttle isn't responding correctly that is something I would definitely check into. The throttle cable positioning bracket (which holds the cable outer housing in place so the inner cable slides to operate the throttle linkage) could be loose or not positioned correctly.

Whenever the dealer says "Oh, that's normal, they all do that", well that means the unit on their sales floor should do the same. Let's Fire it up and show me that is in fact correct. After all, seeing is believing (usually:laugh::laugh:)

It is due to this vibration of the operation of a small engine that it's a good idea to keep an eye on the nuts and bolts on your tractor. Whenever I am servicing the tractor, I usually go from bolt to bolt and check them for tightness. Over time, it's not unusual to find something has worked itself loose. That's why it's important that if you do replace any parts or perform any repairs that you use "Loc Tite" where prescribed and use the correct "Loc Tite" as specified in the Service Manual.

On my diesel, which tends to vibrate a bit, the engine fuel separator / filter canister assembly bolted to the engine block will work itself loose over time. Once, I opened the hood and the entire assembly was hanging on by the fuel hoses and the bolt was gone. Now this is an item which is removed with every service to make changing the fuel filter and cleaning it easier.

It's just a good idea to check the bolts and things will tend to come loose from time to time from vibration. Yesterday I went through my Harley and tightened everything........talk about something that vibrates at idle in it's motor mounts.......(because of the high performance camshaft installed years ago) Let's just say that you never have to wonder if the engine is running when you are setting on it.........It's like the old quarter taking vibrating beds in the "lower priced" motels (or so I have heard........:yahoo::good2:)

Nothing like the "loping camshaft sound" of that THUMP, THUMP, THUMP idle...........It's kind of like a Big Block V-8, if you like the sound of raw American horsepower:usa, these are both sounds which are music to the ears. :pickup:
 

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I will chime in a bit here and am by no means an expert. Just got my X738 last week and currently only have 3.5 hrs on it. Coming from a '16 X590-it is amazing how much more engine vibration you feel in the X738 vs the X590. The X590 was smooth at all engine RPM's-even idle. The X738 definitely has more vibrations at low RPM's, but it definitely feels much better mowing. My X590 and now X738 were finicky with sudden throttle changes from high to low. I think that's just the nature of the small engine's and EFI. Coming from an air-cooled engine to a water-cooled engine....it's amazing how much crap gets stuck to the air inlets around the dash in the X738. The cottonwood trees are blooming like crazy around here in Iowa and it's like a magnet for the air inlets!
 
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