FH500V kawasaki dying without choke... (FIXED)

[mvbighead]

Motor on the Exmark mower I have is not running well.

I took the carb out completely and ran compressed air through everything. Took out the needles, blew out all the passages, and now the engine surges, a LOT.

I've purged all the fuel and put in new, replaced the air filter, and put in two new spark plugs.

It definitely does not run well enough to mow, but I am unsure what else to try here. Under load it dies straight away, without load in only runs while choked. I may just take it somewhere to have it inspected, but figured I'd ask here.

I assume it is a carb problem, but aside from cleaning it up, not sure what else to do.

 

[MiataNC]

Sounds like a vacuum leak.

A "choke" blocks air moving through the carb in order to richen the mixture when cold. So if it will only run choked, even when warmed up, it sounds like too much air is getting into the engine.

 

[PottedMeat]

Under load it dies straight away, without load in only runs while choked.

fuel restriction somewhere? clogged fuel filter? bad fuel hose?

 

[mvbighead]

I do seem to have plenty of fuel flowing through, and had replaced the fuel filter earlier this season.

Too much air... hmmmm. There is one hose that connects to the carb that was not connected on the other end, but for the life of me I couldn't see where it was supposed to go. It was connected to a metal tube at the top of the carb, but the other end is just... hanging.

The tube is connected to "B" in the diagram on page B:
http://www.ereplacementparts.com/kawasaki-fh500vas06-stroke-engine-parts-c-30157_30211_31391.html

 

[MiataNC]

Maybe this will help....
http://www.lawnsite.com/showthread.php?t=334133

 

[PottedMeat]

here's the kawasaki 500v service manual - probably shows exactly where that hose should go

http://www.parish-supply.com/pdf/kawasaki-fh541v-service-manual.pdf

manufacturer's service manual = best manual

 

[boomerang]

To be clear, was it running poorly prior to taking the carb apart or after? Or both?

When was the last time a valve adjustment was done?

There is a vacuum operated fuel pump which may not be supplying enough fuel to the carburetor. If that failed, be sure to check the crankcase for fuel. You might want to change the oil after you replace the fuel pump.

I bought an Exmark late last fall. It has a Kawasaki FR691V on it. I was somewhat dismayed to see that although Exmark does not include it in their maintenance chart, Kawasaki wants the cylinder heads removed and the valves to be lapped every 300 hours of service. Frankly, I think that's rather insane. I would never have anticipated lapping valves every 300 hours - if at all. But that's why I asked if the valves have been adjusted because if you have a valve or valves hanging open, you would not build much power and that could mimic a number of other problems. It sounds like valves may be a bit of an Achilles's heel on these motors.

Edit: That hose you're concerned about I believe is an overflow hose in case the float were to stick. It would not have the other end connected to anything, it would just hang there.

 

[mvbighead]

To be clear, was it running poorly prior to taking the carb apart or after? Or both?

When was the last time a valve adjustment was done?

There is a vacuum operated fuel pump which may not be supplying enough fuel to the carburetor. If that failed, be sure to check the crankcase for fuel. You might want to change the oil after you replace the fuel pump.

I bought an Exmark late last fall. It has a Kawasaki FR691V on it. I was somewhat dismayed to see that although Exmark does not include it in their maintenance chart, Kawasaki wants the cylinder heads removed and the valves to be lapped every 300 hours of service. Frankly, I think that's rather insane. I would never have anticipated lapping valves every 300 hours - if at all. But that's why I asked if the valves have been adjusted because if you have a valve or valves hanging open, you would not build much power and that could mimic a number of other problems. It sounds like valves may be a bit of an Achilles's heel on these motors.

Edit: That hose you're concerned about I believe is an overflow hose in case the float were to stick. It would not have the other end connected to anything, it would just hang there.

It had been running mostly fine with the occasional sputter over the past 2-3 years. A few weeks ago, it simply died towards the end of my mowing, and then I began trying other things.

I got home today, and while it fired up and allowed me to mow for about 10 minutes, it eventually sputtered off and died. And when it was running, it wasn't will full force. I had to back off the speed a LOT to get a clean cut. It seemingly better than yesterday, but I assume I adjusted something with the carb and now it isn't quite right. That, or the stabil I used in the gas possibly purged something in the vacuum based fuel pump. Perhaps that is the next thing to swap out.

And no valve adjustments lately.

 

[boomerang]

It had been running mostly fine with the occasional sputter over the past 2-3 years. A few weeks ago, it simply died towards the end of my mowing, and then I began trying other things.

I got home today, and while it fired up and allowed me to mow for about 10 minutes, it eventually sputtered off and died. And when it was running, it wasn't will full force. I had to back off the speed a LOT to get a clean cut. It seemingly better than yesterday, but I assume I adjusted something with the carb and now it isn't quite right. That, or the stabil I used in the gas possibly purged something in the vacuum based fuel pump. Perhaps that is the next thing to swap out.

And no valve adjustments lately.

I would check the valve adjustment and while you've got the covers off you can see if you have a broken valve spring. The problem not surfacing until the motor gets heated up really sounds like valves to me. It's a no-cost thing to check too. The service manual is linked here with the specs for the valve clearance.

I love this mower. It used to take me 1 1/4 hours with my rider and this does the job in 40 minutes!

 

[boomerang]

Hey, it very well could be a vacuum leak. You'd have to do some disassembly to check the gaskets where the manifold meets the heads. Personally, I think checking the valve clearance first is easier.

 

[mvbighead]

I would check the valve adjustment and while you've got the covers off you can see if you have a broken valve spring. The problem not surfacing until the motor gets heated up really sounds like valves to me. It's a no-cost thing to check too. The service manual is linked here with the specs for the valve clearance.

I love this mower. It used to take me 1 1/4 hours with my rider and this does the job in 40 minutes!

Yeah, it takes me a good hour and a half each mowing, but I would figure a regular rider would be much closer to 2.5 to 3 hours.

As for it heating up, it did seem to run ok after it died the first time for about 2-3 more minutes. I suppose that could be heat, but part of me wonders if that is lack of fuel as when it dies, it just up and stops as if it has no fuel. Could be the heat too, but prior to today, it wouldn't make one pass in the front yard, and today it made about a dozen passes before it finally quit running. Makes me suspect fuel is trickling in over time, and then, when I run, the fuel disappears and can't fill fast enough. Could be wrong, but just grasping at straws.

I am not terribly comfortable with a valve adjustment, but I'll see if I can figure it out with the service manual provided.

If this is what it is, that doesn't seem too bad. Just sucks there is two of them and one will require removal of the muffler assembly to get to. May be doing that at some point here in the future.

https://www.youtube.com/watch?v=NjzX-PUjKmo

 

[RLGL]

Needs choke---Needs fuel
Forget valve adjustments.

 

[boomerang]

Yeah, it takes me a good hour and a half each mowing, but I would figure a regular rider would be much closer to 2.5 to 3 hours.

As for it heating up, it did seem to run ok after it died the first time for about 2-3 more minutes. I suppose that could be heat, but part of me wonders if that is lack of fuel as when it dies, it just up and stops as if it has no fuel. Could be the heat too, but prior to today, it wouldn't make one pass in the front yard, and today it made about a dozen passes before it finally quit running. Makes me suspect fuel is trickling in over time, and then, when I run, the fuel disappears and can't fill fast enough. Could be wrong, but just grasping at straws.

I am not terribly comfortable with a valve adjustment, but I'll see if I can figure it out with the service manual provided.

If this is what it is, that doesn't seem too bad. Just sucks there is two of them and one will require removal of the muffler assembly to get to. May be doing that at some point here in the future.

https://www.youtube.com/watch?v=NjzX-PUjKmo

You're not grasping at straws at all IMO. You're just thinking it through. You don't know exactly what the problem is and frankly, neither do any of us. Unless you work on these things all the time, you have to go through process of elimination to find the problem. If you work on them with regularity, you see patterns that may point you in the right direction initially, but there is no guarantee that your initial diagnosis is correct.

You have disassembled the carb and cleaned it. So, I will assume you're good in that department although your description of what is going on is a little hard to follow. It was running bad, you serviced the carb, then it was surging, then it was running good until it heated up. I may be misunderstanding what you've reported though.

You may have a vacuum leak. Could be where the manifolds attach to the head or the phenolic spacer with gaskets where the carb attaches to the manifold, but I'm sure you got a look at those when you took the carb off. If the carb wasn't loose, I doubt the vacuum leak is in that area. If the manifold is not loose, I doubt that's it too. Still would be a good idea to check it out as part of the investigative process.

You could have a fuel pump that's bad. There is a diaphragm in there that pulses with engine vacuum that pumps the fuel. Generally, those diaphragm's are either good or bad. When they go bad, it's because they've developed a hole in them. You've got a problem that has gotten worse over time and gets worse as the mower is used. I don't see a hole in the diaphragm closing when the motor is cold and opening when the motor is hot. If there's a hole, there's a hole. There is a vacuum line that runs the pump. You should take a close look at that for rot or a crack.

The valves should be adjusted every 300 hours of operation. Only you know if you're at that threshold. If you are, adjust them and eliminate that from the list of possible causes. You'll just be doing the routine maintenance it needs anyway. The video covers the process although the means to adjust the rockers may be a little different. You'll figure it out.

One last thing fuel related. There is a fuel shut off solenoid on the bottom of the carb. When you shut the mower off, that circuit is broken and the fuel flow is blocked off inside the carb to keep it from running on. I doubt the solenoid is acting up but you might want to check the connections related to that.

 

[mvbighead]

You're not grasping at straws at all IMO. You're just thinking it through. You don't know exactly what the problem is and frankly, neither do any of us. Unless you work on these things all the time, you have to go through process of elimination to find the problem. If you work on them with regularity, you see patterns that may point you in the right direction initially, but there is no guarantee that your initial diagnosis is correct.

You have disassembled the carb and cleaned it. So, I will assume you're good in that department although your description of what is going on is a little hard to follow. It was running bad, you serviced the carb, then it was surging, then it was running good until it heated up. I may be misunderstanding what you've reported though.

You may have a vacuum leak. Could be where the manifolds attach to the head or the phenolic spacer with gaskets where the carb attaches to the manifold, but I'm sure you got a look at those when you took the carb off. If the carb wasn't loose, I doubt the vacuum leak is in that area. If the manifold is not loose, I doubt that's it too. Still would be a good idea to check it out as part of the investigative process.

You could have a fuel pump that's bad. There is a diaphragm in there that pulses with engine vacuum that pumps the fuel. Generally, those diaphragm's are either good or bad. When they go bad, it's because they've developed a hole in them. You've got a problem that has gotten worse over time and gets worse as the mower is used. I don't see a hole in the diaphragm closing when the motor is cold and opening when the motor is hot. If there's a hole, there's a hole. There is a vacuum line that runs the pump. You should take a close look at that for rot or a crack.

The valves should be adjusted every 300 hours of operation. Only you know if you're at that threshold. If you are, adjust them and eliminate that from the list of possible causes. You'll just be doing the routine maintenance it needs anyway. The video covers the process although the means to adjust the rockers may be a little different. You'll figure it out.

One last thing fuel related. There is a fuel shut off solenoid on the bottom of the carb. When you shut the mower off, that circuit is broken and the fuel flow is blocked off inside the carb to keep it from running on. I doubt the solenoid is acting up but you might want to check the connections related to that.

Well, I did go ahead and order a new fuel pump. At $12, I figured it'd be worth it just to clear it as a suspect.

As last attempt, it did run for a while. I am not sure if it seems like it is short of fuel when it died off as no choking/not choking changed it, it just sputtered off and died. That would lead me to believe there is no fuel in the carb, but not sure. The hoses all seemed fine when I had the filter off, but I did not take the entire cover off to look at other items.

Given that it ran for a while (just with much less power), I am wondering if I screwed up the carb's adjustment (too much air/too much fuel). I'll be throwing more work at it tomorrow morning, but for now, I figure the new fuel pump should at least help me to clear one more culprit.

 

[Zorba]

Did you use carb cleaner when you cleaned the carb, or just compressed air? If you didn't use the cleaner, I would take it apart and use cleaner. My pusher mower was acting up a lot this year and my weed eater wouldn't even start, after I cleaned the carbs with cleaner they run like new.

Also make sure you got everything put back together correctly in the carb, and play with the adjustments.

 

[mvbighead]

Well, initially I just sprayed some carb cleaner in there. Then later I ran compressed air through all the ports. It ought to be pretty clean, but there is certainly a chance I missed something.

 

[weadjust]

I had a similar deal with my riding mower. I took carb apart disassembled and cleaned. Still ran bad. Took it to a trusted shop. He took carb apart cleaned it and still ran bad. Called me and said I can order a carb rebuild kit or new carb for a couple a bucks more. Labor and parts to rebuild carb was more expensive than replacing the carb. Replaced carb and it runs fine.

 

[mvbighead]

I did read somewhere some talk of people replacing the carb. We'll see if the pump and perhaps another thorough cleaning does the job. It was running ok yesterday until it seemingly runs out of gas. I may have to tweak the carb just a bit more, but I think if it would simply stay running, I could work to resolve the changes in idle.

 

[RLGL]

Clean the carb with an ultrasonic cleaner.

 

[mvbighead]

Clean the carb with an ultrasonic cleaner.

Hmm, never thought of this, but it does seem like a great idea.

Only trouble is, an ultrasonic cleaner of the size needed would run close to $90 (others seem just large of enough for small jewelry like a watch). Definitely would be useful for other things, but need to be sure it would actually do the job.

 

[Zorba]

Hmm, never thought of this, but it does seem like a great idea.

Only trouble is, an ultrasonic cleaner of the size needed would run close to $90 (others seem just large of enough for small jewelry like a watch). Definitely would be useful for other things, but need to be sure it would actually do the job.

How much does the new carb cost?

 

[boomerang]

I am wondering if I screwed up the carb's adjustment (too much air/too much fuel).

I don't really see how. There is no adjustment for the high speed circuit, it is controlled by the main jet. Your only adjustment is for idle mixture. That won't affect high speed operation at all.

 

[mvbighead]

How much does the new carb cost?

The one place I found them it was $230. Not willing to commit to that though. If it comes to that, I'll have a shop check it out first.

 

[mvbighead]

I don't really see how. There is no adjustment for the high speed circuit, it is controlled by the main jet. Your only adjustment is for idle mixture. That won't affect high speed operation at all.

Interesting. Well, I was getting the idle close at one time, but figured I would wait for the pump to see if that resolves the complete dying off issue.

I had talked to my dad a bit the other day, and he suggested it was possible I damaged a diaphragm in the fuel pump when forcing air through the fuel lines. In any case, I should have the new pump tonight and will be popping it on tomorrow most likely and then trying again.

I may also run some seafoam through the fuel system to see if that can improve any remaining bits.

I'm still not sure why it runs poorly during the initial (presumably before the fuel can't keep up) 10 minutes. Too wide of a gap in the plugs? (I believe it called for .030) Coils perhaps?

Maybe the new fuel pump will take care of everything, but I somehow doubt it.

 

[mvbighead]

At the risk of sounding like a moron, I will say that initially on startup it was not uncommon to see some smoke, and through some of my more recent work, it seemed a little more frequent. Nothing terribly, but just enough that it was visible.

Based on a how to article for dummies like me: http://www.doityourself.com/stry/6-symptoms-of-ignition-coil-failure#b

That would seem to suggest a coil pack is a definite possible culprit. As there are two plugs on this guy, I'm wondering if I should just replace both coils. It's a $100, but i am sure it has not yet been done on this fella. Any tests I can do to confirm a coil issue?

Coils I am looking at:
http://www.amazon.com/Kawasaki-Igni...65115&sr=1-1&keywords=kawasaki+ignition+coils