Export thread

Working on a JD 325 with FC540V single cylinder Kawasaki. It was in ROUGH shape when I got it. Intake valve was stuck open, carb was full of sludge, it was bad. I cleaned the carb several times over like nobody's business. I ended up having to replace the float, main jet, main jet holder and gaskets. I removed the cylinder head, removed the valves. Cleaned up the valves and reset them to spec (.06). Cleaned up the piston head and everything on top of that. I've replaced all the fuel lines, new fuel pump, new fuel filter, new oil, oil filter, spark plug and air filter. I've removed the fuel tank and cleaned it thoroughly. Everything on the mower is working correctly, all electrical and mechanical, hydraulic, all working good. I've run a Seafoam treatment through the engine. The engine runs strong but sputters every few seconds and spits out some black smoke, only when it is NOT under load. If I engage the PTO it runs smooth as silk. Makes no difference if the air cleaner cover is removed.

The air mixture screw adjustment seemed to be making no difference so I removed the air mixture screw and gave it a few shots of carb cleaner directly into the jet. The engine seemed to run smooth (or much smoother) when running the engine with the air mixture screw completely removed. I'm guessing that's my issue.


I'm about to take the carb off and do another cleaning. Before I do that I wanted to see if anyone had any suggestions of anything else this might be. Am I missing anything? I know everyone says it all the time, but I had already really cleaned the heck out of that carb.

Is your carb float set correctly? Try to set it a tad lower so it seats the valve a bit sooner. Just a touch.

It's a plastic float so i can't bend the tab to reposition the needle. Is there another way to do that?

I had a lot of trouble replacing that main jet, the jet I got from Trigreen was waaay too big, even though it showed to be the correct part. I had to get the jet elsewhere based on the Kawasake engine model. If that jet is a hair too big, and I mean a hair, would that cause this problem?

Slight oversize main jet won't effect no load running as much as under load. I suspect you have a partially clogged air bleed on the idle circuit of the carb. You have to mix a certain amount of air with the fuel to help atomize it. Without it you will get raw fuel which doesn't burn very smoothly.

arch252 said:

It's a plastic float so i can't bend the tab to reposition the needle. Is there another way to do that?

Click to expand...

Sometimes, simply holding the tab while raising the float will bend them just enough. Careful you dont break it. I have been know to heat them up a little and push on the tab, while out of the carb, of course

Before you do all that though, remove the bowl and flip the carb and see if the float is really parallel too (or just barely above) the carb, and look at the needle to make sure the tip is good. If the floats way off, or you see wear or on the needle tip, you might need to replace needle and float.

I checked the needle before and it looked fine and the float sat level. I guess I'm going to pull it again and go through it once more. I was hoping there might be some other issue I hadn't considered. This could not be a valve issue could it? I was very careful when I set those, but I was also careful when I cleaned the carb!

Was the valve lash 0.006" and your post a typo or did you really set them at 60 thou ?
Way back you were made aware of the idle air circuit, have you checked it is clear ?
How exactly did you clean the carb ?
many times I have to give them multiple baths in the ultrasonic cleaner.
Did you make the rookie mistake of blowing high pressure air from the filter side in thus compacting any dirt in the fine drillings or did you clean it properly engine side out with low pressure air. ?
If you can turn the idle mixture / air bleed screw any more than 1/2 turn in either direction and the engine does not respond at idle then as you were previously told the passage way is blocked.

You have to clean it out backwards so any crud dislodged passes out through the wide end of the funnel.
Once the front bit is clean, block it off with your finger then spray into the screw hole and look for cleaner coming out into the fuel bowl & /or emulsion tube.

That was a typo Bert. I don't have an ultrasonic cleaner so after I completely break them down i soak them in cleaner and then spray them out with the aerosol can cleaner, I don't use any air at all until I have really worked them over with the carb cleaner. I am familiar with the air circuit but no, I have never considered blowing them out from the engine side, I've never paid attention to which side I introduce the air, but I will from now on. I love learning new tricks. I just spent the last hour and a half going over it again. I paid particular attention to the air circuit and I feel as though I may have freed up some air flow so i feel good about it but won't be able to test it out until tomorrow. This was one of the worst carbs I've seen when I started. If it wasnt so expensive to replace one for that engine I would have. Heck, the float alone was $24.

Yes
an hour or two spent working out how to replace Mikunis with a better priced carb is an hour well spent.
I do a lot of work on Amal concentrics and every one some clot has blown high pressure air through the pilot air seat thus moving all of the crud to the pilot air chamber which has two ,003" holes in it to let the air /fuel mix in under the slide.

No luck. I know I had air flowing freely throughout the air chamber. There is one very small hole in the throat beside the choke plate where the air mixture needle will protrude when the air mixture screw is fully seated then three even smaller holes in the throat behind the choke plate. All of those are clear and air flowing freely. Air flowing freely front to back on both sides as well. When i first started it, it ran fine for about two minutes, almost long enough, it seemed, for the carb bowl to fill up and then it started running rich again, just like before. It is still running rich at idle, particularly high idle. At high idle the engine will sputter every 3 to 4 seconds and spit out black smoke. It ran fine under load with the PTO. As I left it at high idle it quickly got progressively worse and then when I engaged the PTO it bogged down and died. When I tried to start it again it began to backfire and would not start. I did not continue trying to start it. I removed the flywheel to check the key and it is fine. I'm going to recheck the valve lash. Suggestions?

I just checked the valve lash. I had set them both to .006 but the engine was cold. I set them at TDC on the compression stroke. When I just checked them the intake was at .014 and the exhaust was .017. The engine was warm, not hot. I wouldn't think a cold engine would cause this much of a difference. The set screws were very tight. I did not pull the push rods. I reset the valves to .006. When I cycled the engine by hand the valves appeared to open fully and everything was moving smoothly.

I drained my oil because it smelled a little off and I wanted to check it for fuel. Doesn't seem to be any fuel in the oil but it did seem kind of thin. Of course I'm out of oil so I'll have to go pick some up to see if the valves made any difference.

Fresh oil in. Valves made no difference. It started easy but sputtered bad from the start like it was choked and died within 20 seconds and would not restart. I didn't keep trying, didn't want to wear down the battery for no reason. Suggestions?

Firstly regards main jets.
Back in the flat head days the only difference between the various Hp ratings within a set of bore & strokes was the size of the main jet and the govenor spring
Thus an 12.5Hp had a slightly bigger main jet than a 12 hp which was sightly bigger than the 11.5 Hp which was slightly bigger than the 11 Hp which was bigger than the 10.5 which had a bigger bore than the 10 hp.
I hope that answers the too big a jet problem.

Next , only gasses can burn so the liquid fuel has to be converted to vapour before it can be ignited by the spark.
Some of this happens inside the cylinder and some happens inside the carb.
At small throttle openings most of the fuel will enter the cylinder via the idle circuit as the low speed air passing over the emulsion tube does not generate sufficient vaccuum to suck the fuel up out of the float bowl.
This is why you have an idle circuit and yours is not working as intended.
Idle circuits work in a variety of means depending upon the design of the carb but most of them deliver a rich air fuel mix into the cylinder to be diluted with the remaining air coming through the main carb venturi.
In your case this rich air fuel mix is too rich causing the carb to be running rich under low load = low throttle conditions.

If you ca not chemically clean it fully then you will either have to remove all of the plugs and physically clean it or replace it.
AFAIK the mikuni rebuild kits do not come with blanking off plugs.
I rarely have to order one as I have the ultrasound and if that can't shift the crud, then it is new carb times as the labour charge in drilling out all of the passageways way exceeds the price of replacement.

Thanks Bert, I'm going to find someone with an ultrasonic cleaner or bite the bullet and buy one.

Any chance these symptoms could be the result of a valve sticking or a faulty coil?

Went through it again Bert, I don't know what I could be missing, there is not a hint of blockage anywhere.

A sticky exhaust valve can cause rich running symptoms at low reves.
I have seen them stick when turning over slow but be fine at faster speeds.
Buy an inline neon tube ( red / orange) spark tester and fit it to the engine.
Watch for irregular flashing when the engine is running rough.

So sounds like valves unlikely to be an issue based on the symptoms but can't rule out the coil without testing it. Here are photos of the carb.

That float is not level..

I see the needle seat, have a pic of the needle?

The mower started out sputtering intermittendly at idle, not under load. That got worse and progressed until it got to where it would bog down and die. Then it would backfire when attemting to restart and then would not restart. That seems like a lot to be caused by what is pictured. I have replaced that needle with another good used needle that I had. No change at all and they both held the float at the same level. I can replace that needle with a new one but seems like I may have other problems.

Pull the engine cover and the flywheel nut and do a quick check of the key.
The 2 halves of the hole should form a perfect square if not pull the flywheel.
As we have stated many times we only have what you tell us & show us to go on.
Usually a partially sheared key will advance the engine which exhibits different symptoms to being rich.
However a retarded ignition will cause some black smoke as the fuel will not have time to burn fully.

At this point in time looks like we will have to start looking at outside possibilities.

I pulled the flywheel Friday and checked the key and it was fine. I'll take the nut and washer back off and snap a picture. I've got the inline ignition tester and I'm going to try to check it as well.

Well, I hate the taste of crow but I'm glad I followed your advice to recheck the key. I don't think this was the initial problem because it won't start at all now and I don't think it would have been running at all before. I think the key got like this when it started backfiring. Perhaps the loose valve lash had something to do with the initial problem. Still not sure how the valve lash got so far out of what, particularly since the nuts were still very tight. I don't have any extra keys so I'll pick up a few on Tuesday and hopefully between that and the loose valves that I corrected I will see some improvement. I'll keep you posted and thanks again for the advice.

On a positive note, at least I have one heckuva clean carb now!

I won't to confess how many times I have failed to tighten the flywheel quite enough, had a backfire sufficient to break the key then spent many hours trying to find the "other" problem.

I was able to pick up a key today. I went ahead and pulled the head and checked for sticking valves. The valves looked great, closed tightly, would not let any fluid pass when seated. I rechecked the valve lash and it was good. I replaced the spark plug again with another new one just in case I had a bad plug. Buttoned it all up and it started right away and ran smooth as silk for about a minute. As soon as it warmed up it started the same thing as before, sputtering at high idle with no load. Every few seconds it would sputter and spit out some black smoke. When the PTO was engaged it smoothed out. The sputter was still there but barely noticeable. I checked the spark with the inline tester. The spark was intermittent when it would sputter. Barely noticeable but not a smooth consistent spark. So...was the spark intermittent because of the sputter or did the intermittent spark cause the sputter? I made a short video where you can hear the engine surge/sputter and see the inline tester. I don't know of any way to upload a video though.

I've about ruled out the float, if it were the float it seems like the problem would have been consistent from the initial start, not a minute later after the engine is warm.

I'm really leaning toward the ignition coil at this point. Am I on the right track? Anything else I should check before I mortgage my house for a new coil?

Part number if you need it 21121-2069 $45 to $62.

That was going to be my next question. When I look it up I see two different coils, both claiming to fit that engine. The one you listed (21121-2069) and 21121-2086.

My engine code is FC540V-DS15. The 13 digit code on my mower is M0G235A070034. It's a single cylinder 17hp Kawasaki.

Based on what I saw I was thinking I needed the 21121-2086, which of course costs twice as much. For some reason the DS15 model is difficult to find parts for. That's what led to my initial problem of finding the right main jet for that carb.

Can anyone confirm?

Stens , Rotary & Prime Line all do aftermarket coils for your engine.

I have used all of them at different times and never had a problem.
Prime Line tend to be the cheapest and their gear has never let me down to date.

Bert, are you leaning toward the coil being the culprit?

Which coil (part #) for that engine?

Yes, that is what the spark test is for.
AT full speed the neon tube testers glow full red.
A misfire or two should not slow down the engine enough to cause the steady red light to flash.
So if you are getting flashing light co-inciding with the misfire the coil is breaking down.
However before you trash the coil you do the same test with the cut off wire disconnected in order to exclude troubles with the mowers wiring.
There are a lot of places to get a random ground short from.

Great idea, thanks!

I checked the coil. I replaced the plug connector just in case that had a bad connection. I removed the ground wire, neither made any difference. I suppose it's time to replace the coil and see if that is the problem. I am confused about which coil I need to get, there are two listed for the FC540V engine.

Kawasaki part #21121-2069 which is John Deere part number AM109258,
Description: Ignition coil for use on single cylinder engines. The models it will fit is 260 265 325 with a FC540V AS15 engine, F525 with serial number above 007892, F710 with a FC540V engine type AS12, 38" commercial mower, 48 and 54" commercial mower with 17hp engine AS11 only and a model LX186 tractor.

and/or

Kawasaki part #21121-2085 which is John Deere part number AM121810,
Description: Ignition Coil that fits John Deere 265, GT262, GT275, with engine numbers of FC420V GS00, HS00, JS00, KS00, DS15, ES15, and FS15, F710 with engine numbers of FC420V DS12 ES12, 325 except engine number AS15, GS75, and HD75 with 17hp engines, and 48" and 54" commercial walk behinds with 17hp engines with DS11, ES11 and FS11 engines.

Neither of these say they are compatible with the FC540V-DS15, the first one just says it's compatible with the AS15 and the second one says it's compatible with the 325 engine except AS15, GS75 and HD75.

Based on this I am assuming I need the second one, AM121810 and of course I can't find this one under $95 and these are non returnable so I want to make absolutely sure I'm ordering the right one. I'm really going to be hating life if I shuck out a bill for that coil and that's not the problem.

arch252 said:

I checked the coil. I replaced the plug connector just in case that had a bad connection. I removed the ground wire, neither made any difference. I suppose it's time to replace the coil and see if that is the problem. I am confused about which coil I need to get, there are two listed for the FC540V engine.

Kawasaki part #21121-2069 which is John Deere part number AM109258,
Description: Ignition coil for use on single cylinder engines. The models it will fit is 260 265 325 with a FC540V AS15 engine, F525 with serial number above 007892, F710 with a FC540V engine type AS12, 38" commercial mower, 48 and 54" commercial mower with 17hp engine AS11 only and a model LX186 tractor.

and/or

Kawasaki part #21121-2085 which is John Deere part number AM121810,
Description: Ignition Coil that fits John Deere 265, GT262, GT275, with engine numbers of FC420V GS00, HS00, JS00, KS00, DS15, ES15, and FS15, F710 with engine numbers of FC420V DS12 ES12, 325 except engine number AS15, GS75, and HD75 with 17hp engines, and 48" and 54" commercial walk behinds with 17hp engines with DS11, ES11 and FS11 engines.

Neither of these say they are compatible with the FC540V-DS15, the first one just says it's compatible with the AS15 and the second one says it's compatible with the 325 engine except AS15, GS75 and HD75.

Based on this I am assuming I need the second one, AM121810 and of course I can't find this one under $95 and these are non returnable so I want to make absolutely sure I'm ordering the right one. I'm really going to be hating life if I shuck out a bill for that coil and that's not the problem.

Click to expand...

High lighted in red does not include engine FC540V at all. I believe I gave you the correct part number of 21121-2069
You are looking for John Deere parts. It is not a John Deere engine it is a Kawasaki. Only look for the engine model number and you will find everything you need and lots of places selling them.

http://www.repairclinic.com/Shop-Fo.../Model-FC540VDS15-Kawasaki-Small-Engine-Parts

21121-2069 google it many choices and prices or go to your local Toro dealer

You've lost me Blaz, I thought part #21121-2069 and part #AM109258 are the same item. One is the Kawasaki part # and the other is the John Deere part # depending on where you are looking up the part, but they are the same part. Same thing on part #21121-2085 and part #AM121810, the first is the Kawasaki part # and the second is the John Deere part # but that is the same part. I wasn't looking for "John Deere parts." I was looking for Kawasaki parts at the John Deere or TriGreen dealer. They do not use Kawasaki part numbers they use John Deere part numbers but they are still Kawasaki parts. If I'm way off on all of this then I need some serious schooling from you guys because you're destroying everything I thought that I knew, what already wasn't much!

You're right that highlighted text does not include the FC540V, it says it fits the John Deere 325 (except AS15, GS75 and HD75) which has the FC540V engine. To confirm that, this is what comes up when I search for the 21121-2085 coil:

Kawasaki 21121-2085

COIL-IGNITION

This part is compatible with the following machines:
•Kawasaki FC540V-DS13 - Kawasaki FC540V 4-Cycle Engine - ELECTRIC-EQUIPMENT
•Kawasaki FC540V-DS16 - Kawasaki FC540V 4-Cycle Engine - ELECTRIC-EQUIPMENT
•Kawasaki FC540V-ES13 - Kawasaki FC540V 4-Cycle Engine - ELECTRIC-EQUIPMENT
•Kawasaki FC540V-ES16 - Kawasaki FC540V 4-Cycle Engine - ELECTRIC-EQUIPMENT
•Kawasaki FC540V-FS13 - Kawasaki FC540V 4-Cycle Engine - ELECTRIC-EQUIPMENT
•Kawasaki FC540V-FS16 - Kawasaki FC540V 4-Cycle Engine - ELECTRIC-EQUIPMENT
•Kawasaki FC540V-GS03 - Kawasaki FC540V 4-Cycle Engine - ELECTRIC-EQUIPMENT
•Kawasaki FC540V-GS16 - Kawasaki FC540V 4-Cycle Engine - ELECTRIC-EQUIPMENT
•Kawasaki FC540V-HS03 - Kawasaki FC540V 4-Cycle Engine - ELECTRIC-EQUIPMENT
•Kawasaki FC540V-JS03 - Kawasaki FC540V 4-Cycle Engine - ELECTRIC-EQUIPMENT
•Kawasaki FC540V-JS16 - Kawasaki FC540V 4-Cycle Engine - ELECTRIC-EQUIPMENT
•Kawasaki FC540V-KS03 - Kawasaki FC540V 4-Cycle Engine - ELECTRIC-EQUIPMENT
•Kawasaki FC540V-LS03 - Kawasaki FC540V 4-Cycle Engine - ELECTRIC-EQUIPMENT

So it appears to me that both coils are for the FC540V, the -2069 coil is for the -AS15 engine only and the -2085 coil is for all other FC540V engines except the -AS15, -GS75 and -HD75. The problem is that my engine is a FC540V-DS15. The DS13 and DS16 are on that list but not the DS15. Of course its not on the list for the 21121-2069 coil either, only the FC540V-AS15 engine is listed for that coil.

I'm sorry to sound like I'm second guessing you but knowing that I can't return a $100 coil if it's the wrong one, I just want to be absolutely sure I'm getting the right one.

As for Repair Clinic, I've checked there for a coil. According to Repair Clinic, all three of the following coils are compatible with the FC540V-DS15: 21121-2069, 21121-2086 and 21121-2070. Just seems hard for me to believe I could pick any one of those three coils at random and any one of them would be good to go.

There are three different types of coils
1) plain coil get used with points or points eliminators
2) coils with multiple terminals used with engines that have an external ignition control module
3) coils with a chip in them , They have a single control terminal.

After that all 3 come is a range of sized to accomodate different sized flywheels
And some have a longer or shorter high tension lead.
fitted new a 5Hp coil will have a shorter HT lead that a 19Hp engine so it makes sense to use different coils but when it comes to replacement parts you can replace either of them with the longer HT lead model.

Add to that, various upgrades over the years and you end up with a lot of coils that will fit.
Some times the old model get deleted while other times it remains in production.
So you ring customer service & check that what you are offered will fit.

Stens & Rotary and Prime Line all do aftermarket coil replacements.
Lookup your coil on their web site and you will see that a single coil can replace 20 or more OEM numbers.

Oh brother, I think I'll head to the Kawasaki dealer and let him tell me what I need, maybe then if it's not the right one he'll have mercy on me. Thanks everyone for the advice.

21121-2086 has the spark plug wire coming out the left side
21121-2069 has the spark plug wire coming out the right side.
That should make it easy to pick the right one.

Been gone a week on vacation but it gave me some time to do some research. The coil I have is the 21121-2085 (or JD part # AM121810). It has been discontinued but there are still a fee out there for about $100. It appears that I can replace that coil with 21121-2086 which is about $40.

Before I order I want to be as sure as possible that the coil is bad. The spark tester seemed to indicate it is. I put an OHM meter on the coil and it read 13.01K OHM's. That seems very high and would lead me to believe the coil is bad. Does anyone have experience running an OHM test on a similar Kawi coil? If so, what does that number indicate?

Only coils for use on a points ignition can be reliably tested with an Ohm meter due to the chip.
A lot of shaved monkeys why learned how to work a video camera put all sorts of junk on the web.
The kit you need to test an ignition module is a bit north of a grand down here so an inline tester on a coil with the kill wire disconnected will do for me.
No one has ever complained and every time I have replaced a coil the engine has worked well after .

Okay, thanks Bert, I'm going to pick one up this week

I suppose it might be time to throw in the towel. I went to TriGreen and picked up a new coil to the tune of $117. Put in on, set the gap and started it up. No change, if anything the surging is worse and more frequent. Instead of running smooth for 2 or 3 seconds and then sputtering for a second with a puff of black smoke, now it is a constant surging that seemed to get much worse as I had it running for about 10 minutes. Finally it got so bad that it bogged down and died. Thinking it must now either be the carb or the valves I removed the carb and went through it one more time just in case I missed something. No change. I removed the valve cover and checked the gap. For the second time I had set the gap at TDC on the compression stroke at .006 for the intake and exhaust. For the second time when I checked they had loosened. The intake was .14 and the exhaust was .11. The push rods were good and straight. I loosened the locking nut and adjusted the set screws to set the gap again at .006. I held the set screw in place while tightening the locking nut. It was too late to crank it to see if that made any difference but I'm not hopeful. At this point I have no idea what could be causing the surging. I have replaced the spark plug twice (in case one was bad), new fuel pump, fuel filter, fuel lines, air filter and pre-cleaner, new battery and the carb has been cleaned about a dozen times. I have fresh oil, oil filter and fresh gas. I'm at a loss and guessing it might be time to take it in and have a professional check it out. That's the last thing I want to do but I'm out of ideas. Don't know why the valve lash is not staying set.

So what happened with the spark tester ?
last we heard from you you were going to get one and check for a constant spark.

If the valve lash seems to changing all the time that is a sign of a loose guide which is new head time

arch252 said:

I was able to pick up a key today. I went ahead and pulled the head and checked for sticking valves. The valves looked great, closed tightly, would not let any fluid pass when seated. I rechecked the valve lash and it was good. I replaced the spark plug again with another new one just in case I had a bad plug. Buttoned it all up and it started right away and ran smooth as silk for about a minute. As soon as it warmed up it started the same thing as before, sputtering at high idle with no load. Every few seconds it would sputter and spit out some black smoke. When the PTO was engaged it smoothed out. The sputter was still there but barely noticeable. I checked the spark with the inline tester. The spark was intermittent when it would sputter. Barely noticeable but not a smooth consistent spark. So...was the spark intermittent because of the sputter or did the intermittent spark cause the sputter? I made a short video where you can hear the engine surge/sputter and see the inline tester. I don't know of any way to upload a video though.

I've about ruled out the float, if it were the float it seems like the problem would have been consistent from the initial start, not a minute later after the engine is warm.

I'm really leaning toward the ignition coil at this point. Am I on the right track? Anything else I should check before I mortgage my house for a new coil?

Click to expand...

I had already checked it with an inline tester a couple of weeks ago.

Sorry. I must have missed that.
I check ignitions by disconnecting the cut out wire and watching.
The magneto sparks each revolution so will always appear solid even when you have a miss caused by the carb.

I have not messed with the governor linkage. It is possible that could have anything to do with this?