ebinmaine 69,958 #1 Posted August 15, 2019 For reference, we are talking about a Kohler k582. For future knowledge, we are talking about pretty much any two cylinder engine. I know what the specs say. Minimum 90 lb. Maximum 15% across two cylinders. What I'm wondering is what your real world experience tells you. How much difference between the two can you really get away with and not .. A. Have something that runs terrible? B. Damage your engine? Share this post Link to post Share on other sites
pfrederi 18,223 #2 Posted August 15, 2019 Army specifies more than 10 psi variance is grounds for turn in to maintenance for an AO-42 engine (air cooled two cylinder 14hp). Talk to the Onan guys with bad valve seats some of them seem to run on one cylinder. 1 Share this post Link to post Share on other sites
posifour11 723 #3 Posted August 15, 2019 (edited) 12 minutes ago, pfrederi said: Army specifies more than 10 psi variance is grounds for turn in to maintenance for an AO-42 engine (air cooled two cylinder 14hp). Talk to the Onan guys with bad valve seats some of them seem to run on one cylinder. And it's returned to maintenance, it'd be pushed all the way to the 40 level (Depot, full rebuild and put back in the supply chain). For a regular consumer, with low-hour use and lives not depending on it, I personally would be ok with 15-20% difference. But, I'm not the owner with skin in the game. That kind of decision is up to the owner's comfort level with it. ETA- I'll say that I'm more trusting of engines than most and have had lots of mishaps. If I was back in the army and doing things right, it would get a full rebuild, but I wasn't paying for it. Edited August 15, 2019 by posifour11 1 Share this post Link to post Share on other sites
ebinmaine 69,958 #4 Posted August 15, 2019 What kind of damage is done if an engine is run with low compression.? Just kind of a future reference question. I don't even know what I'm going to do with this 582 yet but if I was to leave it alone at 95 and 125 ... other than running rough, what happens? Share this post Link to post Share on other sites
953 nut 56,969 #5 Posted August 15, 2019 You might have a bit of reduced power and some ring blow-by resulting in crankcase pressure being a bit high. You may find that there isn't much of a problem after it has run for a while. 21 minutes ago, ebinmaine said: don't even know what I'm going to do with this 582 yet A hot rod comes to mind. 1 1 Share this post Link to post Share on other sites
ebinmaine 69,958 #6 Posted August 15, 2019 3 minutes ago, 953 nut said: hot rod comes to mind. I'll keep you posted of course but if I can get this thing running it's going to end up in a C Series with large wheels 2 1 Share this post Link to post Share on other sites
pfrederi 18,223 #7 Posted August 15, 2019 So the difference ,did the test show it to be valves or rings???? Valves are adjustable and/or cleanable. Rings ..not so much. A leak down test would give you a much more accurate assessment of your issues than the oil and compression test. 1 Share this post Link to post Share on other sites
ebinmaine 69,958 #8 Posted August 16, 2019 24 minutes ago, pfrederi said: So the difference ,did the test show it to be valves or rings???? Valves are adjustable and/or cleanable. Rings ..not so much. A leak down test would give you a much more accurate assessment of your issues than the oil and compression test. Didn't have enough time to get to it tonight. Ran right out of daylight.. I got the switch wired so I have power to the coil when I should, and should not. Probably be Saturday before I get a chance to work on it again. Share this post Link to post Share on other sites
AHS 1,482 #9 Posted August 20, 2019 On 8/15/2019 at 4:22 PM, ebinmaine said: What kind of damage is done if an engine is run with low compression.? Just kind of a future reference question. I don't even know what I'm going to do with this 582 yet but if I was to leave it alone at 95 and 125 ... other than running rough, what happens? Well the 73 wheel horse that I got had 35 lbs...it had sat for 5 years... anyway I put a battery in it and it fired up.. I don’t know how many lbs it has now; but bad valve seats, or just rings? I dunno. But it smoked when I first started it, now no smoke. If your determined to get that kohler twin fired up, 👍😄 ( I would!!)I wouldn’t worry about it. 1 Share this post Link to post Share on other sites
ebinmaine 69,958 #10 Posted August 20, 2019 6 minutes ago, AHS said: Well the 73 wheel horse that I got had 35 lbs...it had sat for 5 years... anyway I put a battery in it and it fired up.. I don’t know how many lbs it has now; but bad valve seats, or just rings? I dunno. But it smoked when I first started it, now no smoke. If your determined to get that kohler twin fired up, 👍😄 ( I would!!)I wouldn’t worry about it. Agreed. I spoke to a couple others in person today. All I can really do is try it and see...... Yepp. Works for me. 1 Share this post Link to post Share on other sites
