Snapper 21" mower engine swap - FJ180V KAI

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  #1  
Old 10-01-15, 06:44 PM
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Snapper 21" mower engine swap - FJ180V KAI

Hi Everyone,

Been a while since I've been on here - hope all is well!

I've got a Snapper CP21550KWV 21" commercial walk-behind from the '90s originally equipped with a Kawasaki FC150V. That mower has about 2000 hrs on it and though it has been EXTREMELY reliable, the engine is starting to show its age. I was never happy with the amount of power even when new so I decided to try something new.

I bought a Kawasaki FJ180V-AM22S (KAI model, oil filter, 25mm x 3 5/32" shaft, variable speed throttle, choke, blade brake) to replace it. From what I understand, Snapper never offered the KAI model on their walk-behinds so I'm in somewhat uncharted territory.

That being said, I've got a few questions:
1. The new motor has a 25mm shaft and the old one has a 7/8" shaft. I have a new 25mm blade adapter and pulley on order. Do I need to order new keys too? The parts lists I've checked are inconclusive.
2. Do they make a front-exit muffler for this engine? I'm worried about the exhaust melting the chute. Some sources I checked seemed to indicate that the muffler from my FC150V will fit the FJ180V, though I have not confirmed that yet.
3. Will my throttle cable and blade brake cable interchange? If not, can someone suggest appropriate part numbers? I'm OK with disabling the brake and rigging a way to ground the coil if I must.
4. Anyone know the thread pitch on the mounting bolts off the top of their head? If not, no big deal I can figure it out.
5. Anything else I might run into that I haven't thought of yet?

Thanks!!

- Joe
 
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  #2  
Old 10-03-15, 02:53 PM
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Ok, made some progress today. Got the new motor on the deck. The IPL lists the engine bolts as 3/8-18 but that's a typo - they're actually 3/8-16. I tapped 3 holes put the motor on the deck and noticed that the muffler guard hits the hump in the hi-vac deck. I used a 4.5" angle grinder and a sanding pad and cut enough off for it to clear.

This particular model comes with a fuel tank but it won't fit - it contacts the driven disc on the self-propelled drive. I removed the bracket and tank from the engine and fabricated a mount on the handle bar where the bag attaches to. I simply took some scrap bar stock I had laying around, drilled two holes through it and two holes through the handle bar and put two 1/4-20 bolts through the whole shooting match. I had 6 ft of 1/4" fuel line laying around and used a fuel shutoff valve to splice the two lines together (the FJ180V KAI doesn't have a fuel shutoff valve). Problem solved.

The blade brake cable is too short. I simply removed the brake assembly from the engine and repositioned the coil ground from the brake assembly to the throttle assembly. No trickery needed here - appears it is designed to be swappable.

The throttle cable was too short. I had a Stens throttle assembly laying around that was a bit longer - that did the job. Just note that this particular engine is REVERSED. A standard Snapper mower's high throttle position is down and low throttle/stop is up. The FJ180V is reversed - up is high throttle and down is low throttle. I may order a reversible throttle assembly from Stens.

My blade adapter and pulley haven't arrived yet so I cranked the motor up disconnected and it purred like a kitten. Excellent throttle response.

The only problem I've been unable to solve so far is finding a front-exit muffler. The side exit muffler that the engine came with will definitely melt the grass chute. When I tear down the old motor (going to rebuild it and give it to my neighbor to replace his POS Briggs 4 HP I/C) I'll see if the muffler looks interchangeable. In the meantime if anyone knows if the FJ180V has a front exit muffler available and can provide a P/N that would be GREATLY appreciated.

Hope this helps someone down the road - looks like this is going to be a winning combination! I can take pictures and post them if anyone cares.
 
  #3  
Old 10-03-15, 03:06 PM
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On a hunch, I checked the part number of the muffler on my FC150V and that part DOES cross over into the FJ180V line. I ordered another muffler - will let everyone know if it fits.
 
  #4  
Old 10-03-15, 04:23 PM
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Yes post pics please I am interested in seeing them !!
 
  #5  
Old 10-04-15, 04:25 AM
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Here's what things looked like when I called it a day yesterday. Took about 2 hrs to get to this point.

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  #6  
Old 10-04-15, 08:38 AM
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Looks great, however, you will probably need to change the air cleaner or put some kind of guard in front of it, while you are mowing you will be running into stuff and under stuff, the banging will destroy the intake. I have Tecumseh XL 2-cycle mounted on a Lawn-Boy deck and that is what happened to it. Have a good one. Geo
 
  #7  
Old 10-04-15, 10:19 AM
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Good point - hadn't thought of that. Maybe a U-bar that bolts onto the height adjusters?
 
  #8  
Old 10-04-15, 03:25 PM
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Point of interest - I pulled apart the old Kawasaki FC150V expecting to find major problems (keep in mind it is almost 20 yrs old and has around 2000 hrs on it). I mic'ed every single clearance and they were all well within spec. The only actual problem I could find was a blown head gasket between the bore and pushrod area.

The valves faces are a little worn as well but everything else is perfect. Ring end-gap spec said max .040". I couldn't get a .015" feeler gauge in there.

Another interesting thing I discovered is everything I've read (including the Kawasaki service manual) says this engine is splash lube and that the oil filter is "fake" on these motors - that the oil pump simply pumps oil through the filter. I confirm without a doubt that the FC150V is a full pressure lube motor (as "full pressure" as a small engine can get anyway). There are holes drilled for lube on the PTO end of the crank and the crankpin. The flywheel side has a ball bearing so that is moot.
 
  #9  
Old 10-04-15, 03:28 PM
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I tried to turn my engine 180 but the bolt pattern wouldn't let me, if yours would it would solve the air filter and muffler problem. Have a good one. Geo
 
  #10  
Old 10-07-15, 06:13 PM
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Tried turning the motor 90 degrees so the spark plug faces left. The oil filter hits the driven disc on the self-propelled. Contacting the driven disc seems to be a common theme here...

The rest of the parts I have on order should be here by this weekend and I'm fairly confident this will complete the project. I'll post pics of the finished product. Hopefully this will help someone down the road re-power a snapper mower - from what I've been told there aren't too many re-power options out there besides briggs motors. I've had more problems with briggs motors after just 200 hrs than I've had with the Kawasaki FC150V after 2000 hrs.

I'm still a bit shocked that the Kawaski service manual could misrepresent their product so badly... parts for the FC150V that should be in the motor (such as an oil slinger) simply aren't there and there isn't even any mounting boss for it! I bought the mower new so I know for a fact it hasn't been tampered with.
 
  #11  
Old 10-18-15, 02:00 PM
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Ok, the project is complete. I can confirm that the front-exit muffler for the 20-year-old FC150V (Kawasaki P/N 49070-2491) fits the FJ180V KAI series with no issues.

I ordered an oil drain tube because Kawasaki appears to have cheapened out on the drain plug. The FC150V had a brass drain plug that you could attach a rubber hose to to make oil changes less messy. The new FJ180V has a plastic drain plug with no such provision. Loosening the drain plug would coat the deck in oil.

I mowed the lawn with the new motor last weekend it the power difference is very noticeable - like the grass wasn't even there!

While it may look like the air filter sticks out in the pictures, it didn't even come close to contacting anything so I don't think a guard is needed in my case.

Here are a few more pics of the finished product - hope this helps someone down the road!

Any questions, let me know!

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  #12  
Old 11-21-15, 07:04 PM
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I am attempting something similar: re-powering my Early '80s 21" walkbehind Snapper with a 25mm shaft engine. If you would, please post the source and part numbers for the blade adapter and pulley you used?
Thanks for your work!
 
  #13  
Old 10-12-16, 07:47 PM
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Sorry for the extremely late reply. I searched through my emails and here are the part numbers. I was working on a couple of machines at the time so not 100% sure but pretty sure these are the right ones.

7015626YP is the blade adapter
7015780YP is the engine pulley for the wheel drive system

The parts were ordered from mowpart.com but anyone should be able to get them.

I love how they still make parts for these older machines!

Joe
 
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