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Kohler 4A22 generator engine parts availability

Carl's repair

Registered
I'm working on a 4a22 right now, had it running and all the electrical stuff works great. It is on propane and is really hard to start from cold, once it's run it starts fairly easy. I discovered now that cylinder 3 isn't helping at all, surprised me because once it's running you barely notice the miss but if I pull #3 plug wire nothing changes. The plug is firing and no change if I swap plugs around also compression on that cyl is only about 20.
The owner doesn't want to put more money into it but I'm curious what the parts availability is for these engines? If it would need rings or valves etc. are they available? I might consider trying to just buy it. Now that I've worked with it and seen it's uniqueness I'd hate to see it just parked or junked.

Update: Thanks Keith for helping me get this in the right spot.

I did check things out more now and I'm wondering if the intake valves on 3 & 4 are not closing completely. With all plugs out (but still plugged in and laying on the head so they would fire) I checked compression etc on each cylinder and a leak down on #3. Seemed like I was leaking out the intake from #3. #4 was also very low compression and I noticed when I plugged #4 hole I could hear more air coming from #3. Would that indicate both intake valves aren't closing completely since the share the same intake port?

I'm thinking these two cylinders hardly helping or not at all is my main starting issue. Still can't believe it ran as well as it did once I got it to take off.

Again, my main question is are parts available like head gasket etc. I'm hesitant to take the head off to check things if I can't get a replacement gasket.

Thanks, Carl
 

Vanman

Subscriber
Last Subscription Date
07/10/2019
Just to be clear, you have a water cooled flathead four, which sits on four cast iron feet, with the generator hanging off the back? That would be the Kohler L600 engine. These are excellent plants.

I have one I’ve been working on, and parts availability has been mixed. Gaskets, seals, and piston rings have not been a problem. But I am still trying to find one more rod bearing.

Keith
 

Tracy T

Subscriber
Last Subscription Date
07/16/2019
not knowing your engine but your symptoms indicate a blown head gasket. with parts availability questionable you need to isolate the two suspect cylinders and recheck to determine where the problem lies. I would start by backing the valve adjustment off on those two cylinders and check with compressed air. you may have to foul the engine some how to do this to keep it from rotating when air pressure is applied. if air is escaping into the other cylinder you may have to go one step more and remove the intake to nail it down. in other words to see how it is getting into the adjacent cylinder. how does the oil look? another test would be to put a pressure tester on the coolant and run it, if it fluctuates that is also a indicator of a blown head gasket. sorry i am not @100% tonight a few pictures would help!
 

Tracy T

Subscriber
Last Subscription Date
07/16/2019
Hell i am overthinking this! please do a compression check on all 4 cylinders and post your findings. I bet its a valve not sealing and bleading over into the other cylinder thru the intake!
 

dkamp

eMail NOT Working
Taking the head off is not a really high-risk situation... unless it's been really seriously hozed, it'll probably come out with no ill isssue for re-use.

Yes, most likely, you just have a valve (or three) that aren't seating fully, and if it's been sitting unused for a long time, it needs a little gentle TLC with a wire brush, lapstick, and valve spring tester anyway.

Drain the block, pop the head off, pull the valve side cover, and rotate the engine, watch all the valves.

Remove each valve, scrub the stems clean, wire brush the valve heads, dig out any crud in the ports, check the spring pressures, drop the valves back in and address the seats with a little grinding compound and lapstick, clean it up, reinstall springs and keepers. Of course, if you find one really-sacked-out spring, then ask, someone here has spares.

"Blown' gaskets don't happen all that often on the L600 that I've seen... the castings are beastly, and even if they're overheated, can't warp much. With compression ratio being very low, and combustion pressures low, and lots of gasket surface, they're not susceptible to gasket blow-out.

Flush out the head and block... stick a long screwdriver, dig around with a coathanger, etc., and flow a ton of water through... because you can. Scrub off the top of the pistons. Drain all the oil, clean off the block. Drop the pan, scrape out the sludge, replace the pan... I don't know from first-hand, but Keith will know if the gasket is likely to survive, or if a bead of RTV will do it.

When you reassemble, wire brush all the bolts. IIRC there's one or two that protrude into the water jacket, and I use teflon thread sealant on those, and anti-seize on all the 'blind' holes.

Unless you find something really-really obvious, a basic freshening-up will wake it up very nicely.

By the way, Carl- Don't think about it any more, just buy it. You won't find anything on the planet that's more dependable, simpler, more reliable, easier to work on, and sweet running, than that little bugger... and it's output rating is VERY conservative.
 

Zephyr7

Registered
Careful putting any thread sealer or other compound that can act as a lubricant while tightening a bold — you can overtorque things that way if they’re in critical spots.

Bill
 

Carl's repair

Registered
Thanks everyone for the helpful info. I left it set for several weeks and now the owner called me and said, lets fix it, it's no good like it is. So.... back to it.
Took side cover off and checked valve clearance hoping to find a couple of tight intake valves on #3 and #4 explaining the air sound changing in #3 plug hole when I check #4 compression. Intakes were slightly less than speck but not tight or holding valves open. I had already checked valve movement thru plug holes and all are free.
I did notice this time checking compression on #2 that the sound in #3 plug hole changed as well. I'm thinking head gasket now but haven't succeeded in coaxing the head off yet.
Do the studs holding the thermostat cover on have to come out? Or does the head slide off of them without removing the studs? That is all that is holding but they are rusty and it wont come up. Don't want to use too much force but I put some rope in #1 plug hole and if I put pressure up with the piston the head wiggles but won"t move on that corner. Pretty sure that's all thats keeping it on.

Thanks Carl
 

Vanman

Subscriber
Last Subscription Date
07/10/2019
The thermostat studs are threaded into the block. Probably just rusted up inside the holes in the head. Once free, the head will lift off, leaving the studs behind.

Keith
 

Bent Trigger

Subscriber
Last Subscription Date
10/03/2019
Liberal amount of PB Blaster and movement no matter how slight will free the head. Patience and tenacity. You can not use too much PB!! 😸
 

Carl's repair

Registered
Thanks Keith. That's what I thought but wanted to double check so I don't break something. Don't think I ever acknowledged, it is the L600.

I've been soaking it with Deep Creep off and on for several days. It'll come yet now that I know for sure what I'm working towards. Ready to have it off so I can see what's going on.

I'll try to let you know what I find.

Carl
 

Carl's repair

Registered
Well i'm finally back with results. Tried off and on for a couple of weeks and finally got the one stud to loosen in the head and then come out of the block so I just had one holding. That one didn't seem to care what I did, it wouldn't loosen up. I double nutted the top end so I could try to "flex" them and work lubricant (tried several different kinds, even homemade brew, acetone and trans fluid) down in them, that's how the one loosened up and then backed out.
Finally put rope down #1 plug hole and pushed up with the piston while tapping on the stud and managed to get the head to start moving up. Spent nearly 3 hours yesterday pm till I got it high enough to see that the gasket was indeed bad and I could turn the head enough to know the stud would come out of the block. Once I finally had it high enough to leave something to get ahold of, I cut it off below the head. Now I can press the remainder out of the head and also remove the short piece from the block with a visegrip.
The head gasket has about 3/4 inch gone between #3 and #4 cylinder and was starting to go between #3 and #2 also. Can't believe this thing actually started and ran much less ran half decent with the gasket in that bad of shape!
Can anyone point me to a good place to find a replacement head gasket? What should I expect to pay etc. I think that's all I'll need. Any other minor gaskets I can just make.
Thanks again for your help. Carl
 

Vanman

Subscriber
Last Subscription Date
07/10/2019
I’m not 100% sure (memory is dubious) but I believe I got a lot of my parts from Colburn Power.

But also try eBay and even a general web search with the part numbers.

Keith
 

Carl's repair

Registered
Your memory's still good. They had one and looked like the best price from what I found.

I've got things cleaned up and ready for the gasket, I'm looking forward to hearing this thing purr on all four!

Sure appreciate the help, Carl
 

Tracy T

Subscriber
Last Subscription Date
07/16/2019
If you plan on keeping this unit I believe i would snatch up another gasket, WHILE YOU CAN STILL GET THEM!
 

Carl's repair

Registered
The head gasket number is 241453. Not sure about the manifold gasket number as I didn't need one. I got the head gasket thru Colburn Power, was around $85 with shipping.
And, I've got this one purring again! Thought it ran good before, well, now it pops right off and just sits and purrs. Pulls a load well and everything seems to be like it should be. Owner decided to hang on to it for now, Maybe later I'll get a chance at it, who knows.
Thanks again all of you for the help.
Carl
 

Partsman

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Last Subscription Date
02/05/2020
I have manifold gaskets for the 600 Jim,s Antique Small Engine parts, Sponsor on this site
 
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