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My Cummins onan 2.8 just started developing a nasty oil leak, I recently discovered it was getting very hot by the head I've got it leaned out as far as I could get it without surging new plug new oil 660 hours on it after I felt it was getting a bit hot from the backside I went through and tuneducated everything still runs to rich and stinky had nasty crap in the bottom of the crankcase so I ran it 3 times changed oil three times got it smooth and nearly clean running then got it hot changed the oil again and now oil is soaking the rag I have plugging the drain hole after it started leaking more and more I found, small leak by the head two headbolts were tight the right side two were not but I don't see the big leak leaking almost a ounce every hour oil starting to develop around head by gasket before I tinkered with anything. I was forced to add air hole locations around head area as head was just getting to hot no matter what I do since I got it using racing 40 with a little zinc it runs good now heat not so bad but right near the bottom of the motor is a leak I cannot find not drainplug, anyone know how hot these things are supposed to get and where most likely a oil leak will develop on the onan 2.8 which is used with nearly every dolphin? Small leak by head and oil coming from back near drain plug getting worse and worse everything runs great on it but I can't nail this oil leak unless I rip the generator out if these things overheat do they crack or warp or what? Please someone has to have run into this issue I did hit a pothole that may have nailed the already damaged deck with asphalt but I found no damage indicating this could have nailed my Cummins 2.8 onan starter and brushes I do know need replacement so many hours the starter is having troubles kicking the first couple strokes found small amounts of oil leaking into the cylinder might be the cause after giving thicker 40 racing oil as it is worn and has no oil filter kicks easier now finding lots of oil leaks but hardly have to fill it I'm not finding much that I have to refill with been a week soaked three rags put maybe a ounce of oil in it if that already 50 hours since last change I've looked all over only one spot I'm seeing fresh oil come out by the head near muffler how durable are these things to heat someone please help about to lose my rear end all my leaf spring bushings are mostly gone icant afford another generator or home, lost my doctor again no chance of surgery because this is my only home nothing to help with pain management and I need tons of meds to live but because I'm homeless in which racist doctor caused because he hates America I'm screwed every day is a year off my life if I tear this out I have to know what I'm looking for so I'm prepared for the worst please help just getting the conduit out means bending the coach frame support its pinched in between frame and deck no clue how I can get conduit free far enough to get the genset out I can't afford another generator 660 a month doesn't even get me plugged in for 3 weeks in Oregon.

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Running lean will cause overheat. I assume these gen sets have points, sounds like timing or vacuum leak. Timing probably set with correct points gap. Vacuum leak could be because your head bolts were loose. My opinion, pull it out of the coach so you can really look it over. Continuing to run it in it's present condition could cause irreversible damage.

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I looked up the specs on this 86 model and saw nothing indicated about points does run slightly rich but as soon as I started using it I got on top of the heat issue it really hadn't been used much in Las severalyears so sediment had collected at the bottom when I first checked oil before starting it looked clean not even twenty hours it was black, has a new carb no leaks I could find nothing inside but that that has been touched original everything has gears for timing but I've got that idle lean rich screw a half a turn out it from all the way tight it runs so rich went to a ngk plug standard helped it run smoothly heat didn't change lean or rich starter is nearly dead or timing is off somehow but if it sits in heat for long enough it doesn't have a issue starting or running just started leaking after last oil change I think it's already been overheated and someone put stop leak of some sort in it and is why it leaks I've looked all over tiny leak by head where it bolts too block but most of it is coming from the backside of crankcase or oil cover somewhere I can't see, everywhere from the front of cover everything is clean and intact and exhaust isn't buring my eyes or hand 3 inches away from end I was just hoping if it did get damaged overheating before I got it where most likely it would crack warp or leak and where? I can't check the timing without tearing it out but appears from my experience and my pdf specs timing is good or it would be surging like crazy and nothing would let it run right as far as fuel mix have the throttle screw at a a quaternary turn with 2500 watts being pulled off it runs great perfect mix not to lean or rich just this damn oil leak and a starter with wiring that was redone for another generator definitely not the original from the shit ball wiring job it had has external resister diode and charging system with a failed diode ran two 30 amp relays to a switch when it's at 50% auxiliary power I use that like the diode would work according to specs when I run for more the a hour I have it switched to a 2/10/50 amp charger so I can alternate and not overload anything using a set up of relays nothing coming off onan that goes too auxiliary or too regulator power inverter assembly. Only wires are the 3 120 ones the electronic regulator wires white one missing oddball for old onan and a white ground rated at 90 amps by gauge size for everything and one from battery for the battery to truck motor another underrated wire goes from that battery all the way to auxiliary was charging good at first then after plugging in the diode died or my brother vandalizing my box with a pressure washer unsure when I got it someone had just put in this generator and I don't think hardly ran it had 600 almost when I see it was swapped out but everything looked correctly done to specs and it puts out good ac voltage hope you might have more insight stator and armature seem a bit hot on start up nothing scolding no more then 195 degrees when I checked it on first run but second run the deck fell apart which kicked the temperature up about 20 extra degrees bUT it's been in the 90s also put some holes by the head near exit for the air to flow a bit better got way cooler haven't put more then maybe 80 hours on it since I fixed the dirty oil and deck and heat issues heat exit is where the exhaust comes out good amount of air flow now. Eerg I can't let it burn up and die it is a model with oil level switch and electronic ignitor weird thing is I haven't hardly had to put any oil in it and it let's me know if it's even a little low.

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After I snuggled the head down a little on the right where I saw the leak it nearly stopped definitely head gasket leak by the push rod area torque was way loose on right side still a little tiny leak keep a eye on it but that appears to be what happened got to hot before I got it and screwed up the bolt tightness because gasket got crushed, it will go for awhile but eventually I got some work to do, brush replacement,  starter, head and diode for the inverter been running it all day no issues still a bit warm but muffler is pretty rusted and area by it where air passes through is a little torn up insulating the muffler from motor, at least it's not cracked thank god

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