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Subject: 9n blown head gasket or cracked head

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Jerry Gere    Posted 02-08-2017 at 23:10:09 [URL] [DELETE]        [Reply] [Email]  
  • 9n blown head gasket or cracked head
  • I have had a 9n for about 20 years. Had a rebuilt engine installed when I got it. Been running fine since with only regular maintenance. Recently i was running it pretty hard skidding and loading logs. Was backing up with nose down on steep bank when radiator started to boil over. it has never overheated even brush hogging in summer. I pulled away from steep slope and it ran fine, checked coolant and was only down slightly.

    Since then, it's winter in NEPA, it has been really hard to start. Sounds like no compression/ firing on one cylinder until after minutes of on and off cranking runs on two cylinders, backfires a few times, then three cylinders then four and runs fine.

    Next time it starts cold same thing. I recently noted that coolant is going down slowly and the oil dipstick is brown/milky foamy. Compression ranges from 105 to 115 psi front to back. I set each cylinder at TDC and applied 120psi compressed air. No bubbles in radiator but there is steady blow by from dip stick hole. Of course i have not done these tests in the past because it was running good!

    Thank you for reading this far. Ideas?

    Jerry Gere    Posted 03-18-2017 at 23:39:43 [URL] [DELETE]        [Reply] [Email]  
  • Re: 9n blown head gasket or cracked head
  • Ok folks, sorry for the long delay. Your collective advice was right on the money! Did tune up including new plugs, points and condenser, distributor cap and rotor. Changed oil and filter, topped up coolant (just above the top radiator hose inlet) There is a small baffle in the radiator at that level.Now starting and running fine! This is a working tractor. Never been garaged. I have been careful to keep it covered when not in use, especially when rain or snow is forecast. That said there were a couple times last fall when I did not cover it and we got heavy rain. So a little water got into the crankcase through a faulty oil filler cap. The "cap" was a piece of a round tree branch that I stuck in the filler pipe when I lost the original cap in the woods. So now i see that i also have water in the hydraulic oil, no doubt from the same rain. The boot on the gear shift is in bad shape so that was inviting the water in. A classic lesson, look for the simplest stuff first! Thanks again. Jerry

    steveVa    Posted 02-09-2017 at 11:16:00 [URL] [DELETE]        [Reply] [No Email]  
  • Re: 9n blown head gasket or cracked head
  • Sounds like it could well be a blown head gasket. Also sounds like your distributor got wet and you need to dry out good and set the points and clean all the connections. Sometimes just unpluging the plug wires and putting them back restores a good connection. If you were nose down and the radiator was overfilled it may have just overflowed and not overheated.

    Jerry Gere    Posted 02-09-2017 at 22:11:46 [URL] [DELETE]        [Reply] [Email]  
  • Re: 9n blown head gasket or cracked head
  • Thank you for the input! I am taking a night off from the 9n in the garage. It's 10deg F out and I did not feel like firing up the heater.
    I have not pulled the distributor lately, I did confirm a nice strong blue spark during one recent startup session. When I get back to work on it I will pull cap at least to make sure points are clean and dry. In 40 plus years of tinkering I have developed an if it ain't broke don't fix it attitude with ignition points.
    Engine oil and filter were changed in fall and I have never seen that foamy light brown look of water in the oil with the 9n.
    Thanks again and I will keep you posted. Sap is going to run this weekend and I need the 9n to gather it...

    Rustyal    Posted 02-09-2017 at 09:53:23 [URL] [DELETE]        [Reply] [No Email]  
  • Re: 9n blown head gasket or cracked head
  • I agree with Tim. You should do a tune up. Don't overfill the radiator. Fill it up just past the cooling tubes. A few inches from the top. Then run the tractor and see if your oil is contaminated. Cause it sounds like you have a few things going on.

    Tim Daley(MI)    Posted 02-09-2017 at 06:21:33 [URL] [DELETE]        [Reply] [No Email]  
  • Re: 9n blown head gasket or cracked head
  • Hi Jerry-
    It sounds like you may have a multitude of issues going on. First, don't overfill the radiator. Often this is the culprit for overheating. Murky oil or hydraulic oil? Clean fresh motor oil should be a honey brown shade and hydraulic oil too. Engine oil will be black or dark brown if its old. Murky foamy oil is a sign of water contamination. A cracked head would get water in your engine oil. Misfiring and backfiring could be an electrical problem. When you boiled over the radiator, chances are good you got your distributor wet and thus will need to pull it off and may as well rebuild/tune it up once you do that. Bad wiring and/or short can cause misfiring and backfiring too. When was the last time you did tune up and oil change?

    Tim *PloughNman* Daley(MI)

    *9N653I* & *8NI55I3*

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