Blown Head Gasket
pxctoday

» Log in

User Name:

Password:

Not a member yet?
Register Now!

» Find OEM Parts

» Jobs

» wallpapers

Page 1 of 3 123 LastLast
Results 1 to 10 of 25
  1. #1
    I dream skis E350's Avatar
    Join Date
    Jul 2015
    Location
    Sacramento Delta, CA
    Posts
    529

    Blown Head Gasket

    1988 Kawasaki X2 650: I thought that maybe there was air being sucked in through the crankshaft. So I was interested in learning how to do the leak down test. Here:

    http://www.pwctoday.com/showthread.php?t=476515

    But @Myself said this: "
    I use the air compressor with regulator turned down for 10psi. Im guessing you have a blown head gasket. Take off the cooling line from the head and smear soap bubbles over it then put some air into the pulse fitting. If the bubbles start blowing up then you have air leaking over to the cooling side. Normally from the head gasket."

    In fact, there have been a couple of symptoms I observed that are consistent with a blown head gasket. For the last 4 or 5 trips, the exhaust has been "hotter" and more gaseous than usual -- less "water full" than usual. Engine compartment seemed hotter than usual.

    Well now we know:

    DSC09011.JPG

    Winner winner chicken dinner! = Myself

    See that blue hose coming from the head where I stuck my $5 ebay stethoscope into? That was just pouring out air. And when I remove that red cap from the right angle brass fitting on the head, air pours out that too.

    A couple of things of note. My home made block off plates don't seal off air. Although this neoprene was supposedly closed cell foam it clearly is not. I probably need some wetsuit neoprene. There was no visible air leaking from the crank seal or from the flywheel cover with the flywheel cover plug screwed in. Air pressure used was 5 lbs. No need to do a vacuum test until I fix (hopefully only) the head gasket.

    ANY SUGGESTIONS FOR WHERE TO BUY THE HEAD GASKET AND HOW TO INSTALL IT WOULD BE APPRECIATED ! ! !
    Last edited by E350; 09-03-2018 at 03:59 PM.
    Learning Slowly...

  2. #2
    PWCToday.com Is My Home Away From Home
    Join Date
    Oct 2013
    Location
    funky town
    Age
    87
    Posts
    7,254

    Re: Blown Head Gasket

    Use actual rubber. Like an inner tube.
    Hit up zigler, at watcon/rcjs. His user name here is john zigler.
    I'm only here to make you mad



    I'll tell your girl you said "hi".


  3. #3
    I dream skis E350's Avatar
    Join Date
    Jul 2015
    Location
    Sacramento Delta, CA
    Posts
    529

    Re: Blown Head Gasket

    Good News! I didn't blow the head gasket!

    There wasn't one.

    DSC09012.JPGDSC09029.JPGDSC09028.JPG
    Learning Slowly...

  4. #4
    PWCToday.com Is My Home Away From Home Myself's Avatar
    Join Date
    Jun 2006
    Location
    Arkansas
    Age
    43
    Posts
    5,743

    Re: Blown Head Gasket

    Looks like a nice setup. .25mm over rebuild with recut and o'ringed stock head. Guessing there is mild port work too. I see several areas in the head closeup where exhaust gasses have left a trail out to the cooling holes in the head. Good news is don't touch the carb......that wash pattern looks great. Get some new o'rings and use a dead flat surface and some 320 wet sandpaper to smooth up that head.
    http://www.facebook.com/twinlakesjetskirepair

    '89 Kawi 650SX 42.4 GPS
    +3" stock pipe, ported ex. manifold, drilled waterbox, blueprinted pump, Ocean Pro ride plate

    '99 Yama GP1200 65U 61.8 GPS
    ported cylinders, matched cases, milled head, blueprinted pump, long ride plate

    '96 Seadoo HX 717 53.13 GPS
    light porting, massaged cases, lightened flywheel, port matched manifolds, Rossier pipe, stubby pump cone

  5. #5
    I dream skis E350's Avatar
    Join Date
    Jul 2015
    Location
    Sacramento Delta, CA
    Posts
    529

    Re: Blown Head Gasket

    Hey Myself !

    Thank you for answering my thread! I am confused though. Do I not order the stock flat head gasket and buy "O" rings instead? If so, where do I buy the "O" rings and what size?

    Eric Burton (currently in Lake Havasu City) built the engine so it doesn't surprise that it is modified. I won't touch the carb.

    Finally, I guess the elephant in the room is why do you think I blew the "head gasket" and how can I avoid that again? It looks like it had an additional cooling exit on the head (that right angle brass thing with the red cap on it). Should I try to get dual cooling going again?
    Last edited by E350; 09-03-2018 at 07:58 PM.
    Learning Slowly...

  6. #6
    PWCToday.com Is My Home Away From Home Myself's Avatar
    Join Date
    Jun 2006
    Location
    Arkansas
    Age
    43
    Posts
    5,743

    Re: Blown Head Gasket

    An o'ring head doesn't use gaskets. Just new o'rings and sealant. The rubber o'rings get burnt out quicker than a standard head gasket with metal rings. Clean the head, color it with a sharpie, then rub it on some 320 grit. Just need to make sure it's true. Measure inner and outer groove with caliper and thickness, that will be your o'ring size. A place like Mcmaster Carr will have them.
    http://www.facebook.com/twinlakesjetskirepair

    '89 Kawi 650SX 42.4 GPS
    +3" stock pipe, ported ex. manifold, drilled waterbox, blueprinted pump, Ocean Pro ride plate

    '99 Yama GP1200 65U 61.8 GPS
    ported cylinders, matched cases, milled head, blueprinted pump, long ride plate

    '96 Seadoo HX 717 53.13 GPS
    light porting, massaged cases, lightened flywheel, port matched manifolds, Rossier pipe, stubby pump cone

  7. #7
    I dream skis E350's Avatar
    Join Date
    Jul 2015
    Location
    Sacramento Delta, CA
    Posts
    529

    Re: Blown Head Gasket

    Myself: Thank you buddy! I actually understand that. It is like bluing on a rifle stock to see what is high and low. I will ask a machine shop what they recommend for a "dead flat surface." Should I remove the head studs and sandpaper that surface as well?

    Will report back with pictures. Have a great week!
    Last edited by E350; 09-04-2018 at 12:22 AM.
    Learning Slowly...

  8. #8
    I dream skis E350's Avatar
    Join Date
    Jul 2015
    Location
    Sacramento Delta, CA
    Posts
    529

    Re: Blown Head Gasket

    You know, now that I have slept on it, I don't think that the apparently unrestricted large volume of air coming out the the blue water jacket cooler line can just be from a leaky "O" ring. So, I am going to rotate the pistons and look carefully for a crack in the piston cylinders. I guess it is also possible that a leak could be where the cylinder block attaches to the crankcase, but I have no desire to break that seem to look unless I absolutely have to.
    Learning Slowly...

  9. #9
    PWCToday.com Is My Home Away From Home Myself's Avatar
    Join Date
    Jun 2006
    Location
    Arkansas
    Age
    43
    Posts
    5,743

    Re: Blown Head Gasket

    An old window or scrap piece of marble or granite countertop will work fine as a flat surface, probably even your kitchen countertop. Put a ruler on edge and shine a fkashlight on the backside, if it's good both directions tape the 320 down and wet it with soapy water. No need to push down on the head, just back and forth a couple enches each direction and check your "bluing".
    At a machine shop they have what is called a sign plate. It's a heavy cast iron part used for checking flat edges.
    Normally the cylinder deck doesn't warp like a head as it's a much larger,thicker part. When doing a full overhaul I true up every gasket surface.
    http://www.facebook.com/twinlakesjetskirepair

    '89 Kawi 650SX 42.4 GPS
    +3" stock pipe, ported ex. manifold, drilled waterbox, blueprinted pump, Ocean Pro ride plate

    '99 Yama GP1200 65U 61.8 GPS
    ported cylinders, matched cases, milled head, blueprinted pump, long ride plate

    '96 Seadoo HX 717 53.13 GPS
    light porting, massaged cases, lightened flywheel, port matched manifolds, Rossier pipe, stubby pump cone

  10. #10
    I dream skis E350's Avatar
    Join Date
    Jul 2015
    Location
    Sacramento Delta, CA
    Posts
    529

    Re: Blown Head Gasket

    I have never had the head off a two-cycle jet ski engine before, so I have the following observations and questions:

    1. I peered down through the water jacket holes in the cylinder block into the water jacket cavities and noticed that the water jacket cavities are extremely clean bright shiny aluminum (so likely no intrusion of exhaust gasses into the jackets in the cylinder block. For some reason I thought that the water jackets protruded through the cylinder block gasket into the crankcase block, but they don't so that gasket cannot be the source of the leak.

    2. The cylinder sleeves have no cracks and look good to me.

    3. So the exhaust gas is likely going directly from the piston cylinder across into the water jackets in the head. I will measure and buy nytril "O" rings.

    4. Or, since I replaced the exhaust manifold a month or two before I noticed the "too hot" / "more gaseous than usual" exhaust symptom. Is there some way that pressurizing the cylinder with compressed air could cause the air to escape from the crankcase to the exhaust manifold to the cooling lines in the head?

    5. Are those "domes" in the cylinder head milled into the cylinder head material themselves or are the domes a separate component which is fit into a cavity in the cylinder head? If they are separate, what keeps them stuck in place?

    6. Finally, to true the head the Practical Machinist's forum says (like Myself says) to use silicon carbide paper, not sand paper or aluminum oxide paper, and a petroleum base fluid like kerosene or mineral spirits on a true flat surface like glass.
    Last edited by E350; 09-05-2018 at 01:09 PM.
    Learning Slowly...

Page 1 of 3 123 LastLast

Thread Information

Users Browsing this Thread

There are currently 1 users browsing this thread. (0 members and 1 guests)

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  
Powered by vBadvanced CMPS v4.2.0