1978 GS750 Head or Exhaust Oil leak?

[mmaurin]

i thought i had a oil leak at the head gasket, but now im not so sure...
it seems to be leaking from the bottom of the exhaust valves... if thats true, does that mean my rings are shot becuase im getting oil out of the ports? my exhaust is not smoky... so im a little confused...

here's some pics... i just realized i must have broken the cam cover gasket because im getting oil on the right inside spark plug wire... which is a new leak... that was an expensive gasket too...





tach hole dry
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oil on the lower fins but not upper
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higher exhaust bolts dry, lowers wet...
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I torqued the head bolts...
i put a little pressure on the exhaust bolts and they all turn freely (which is great because i hear they get stuck and break off easily) but may have been loose... so maybe just 4 new exhaust gaskets? but still if oil is coming out, and not gas, thats a bad sign right? do these bolts touch oil jackets within the head/case?

[tom203]

Get a OEM cam cover gasket- prices seem to have almost doubled in last year at dealers-. clean old gasket off carefully and thoroughly. This is a likely source of leak finding its way down fins.

[earlfor]

There is no oil to leak from the exhaust manifold. I see three possibilities. There is a "O" ring seal on the tach drive on the cylinder head that commonly leaks. There is a gasket on top of the cylinders/jugs between them and the head, and in the front center of the engine between the 2 and 3 cylinders, there is a bolt that can only be seen when laying under the bike and looking up at it. Sometimes that bolt works loose, weeps oil down the center and airflow blows the oil around the head and across the gasket seam. I think it's a 10mm, so if it is loose, don't go gorilla on tightening it. It WILL break or strip if you do.

If the oil leak starts below the valve cover gasket, then that gasket is not the problem.

[mmaurin]

thanks
i bought an oem one from my dealer, im assuming its no good to put it back together with a little gasket gunk like i do with the half moons at the end ogf the cams... or could i?

the 10mm bolt that you speak of can be torqued to 14.5-18.1 for a standard bolt or 21.7-26.8 for a "S" marked bolt... does it need a lock washer or copper washer to seal better?

how hard is removing the head and replacing that gasket? do i need special tools to deal with the pistons and/or rings? i assume some pistons will be sticking part or the way our of the cylinder at top dead center...

[earlfor]

thanks
i bought an oem one from my dealer, im assuming its no good to put it back together with a little gasket gunk like i do with the half moons at the end ogf the cams... or could i?

the 10mm bolt that you speak of can be torqued to 14.5-18.1 for a standard bolt or 21.7-26.8 for a "S" marked bolt... does it need a lock washer or copper washer to seal better?

how hard is removing the head and replacing that gasket? do i need special tools to deal with the pistons and/or rings? i assume some pistons will be sticking part or the way our of the cylinder at top dead center...

Before you do take anything apart, you must first know where the leak is originating. Get a can of spray on degreaser (Gunk or whatever). Buy a can of spray starch too. Degrease the area from the valve cover down to the engine cases and rinse well with a hose. Get it as clean as you can. Let it dry. Then spray the suspected areas with the spray starch and let that dry. It will be white when dry. Once the starch is dry, start the bike and let it run while watching closely for any oil stains that appear.
When we know where the leak is, we will know what we need to do to get it fixed.

[mmaurin]

so i scrubbed like crazy last night, blew it dry and used the spray but it wouldnt dry white... is there a specific brand of strach that dries white? i expected it to be a little foamy when you said that it would dry white... honestly, ive never used starch to iron, and i cant recall my mom doing so either... so i was taking a shot in the dark...

i almost bought the one that was called "niagra" because it had a foamy picture of hte falls, but i bought faultless heavy starch instead...

[1_v8_merc]

If you replace the head gasket, the piston-rings won't come flying out, the pistons can't go any higher than the cylinder jug. However, you will have to reset the engine-timing, once you take the cylinder head off. All you do is rotate the engine and line up the marks for 1-4(points plate), then set the Cams to the appropriate position. You also must pull up the timing chain prior, to take up the slack, and reset the Tensioner too.
(it's actually very simple, just look in the manual.)