Do you guys think I need a new head gasket?

[Jpich85]

I pulled the engine out from the back of the garage after its been there for over a year, I thought I'd run a compression test on it to see if it was OK just to paint and fit back in the bike. 

I bench tested it and was getting 150 across the 4 cylinders but afterwards I noticed it was wet with oil along the head gasket line. 

I know this engine looks in a dirty state anyway but it definitely wasn't wet with oil when I started the test and it's been drained of oil for a year. 

I won't to fix whatever issues it's got and I'm thinking it'll need the head off and new gaskets and a look to see what's what on the pistons.

It's from a 1985 slabside 750 with unknown milage. 

If I do take the head of is it worth doing the piston rings while I'm there but obviously that'll be more money.

I'm not sure what's best to do this will be my first big engine work I've done. 

Someone people told my it's the camcover gasket but it's not wet with oil there so I don't think it's that. 

[coombehouse]

Looks like the cam cover gasket has been leaking for a very long time.

[Devilman]

1 minute ago, coombehouse said:

Looks like the cam cover gasket has been leaking for a very long time.

Yup, this is the conclusion I came too also. The 4th and 5th picture clearly show that classic "oil and dirt" caked to the chain tunnel, right up to the cam cover.

[Captain Chaos]

9 hours ago, Jpich85 said:

it's the camcover gasket but it's not wet with oil there so I don't think it's that. 

there are oil/dirt drain holes from the spark plugs to the front of the engine, just below the exhaust ports.

If oil reaches the spark plugs (faulty cam cover gasket for example) it leaks out like on your engine and looks like a leaking head gasket.

[Jpich85]

Thanks everyone I'll give that another look then, 

If I was to change the head gasket and I kind of won't to change those oil tubes as they are really rusty, 

Would I need to change the base gasket also?

Would I need to replace the piston rings too if I remove the barrels to do the base gasket or can you still re use the piston rings once you remove the piston from the barrels?

It's a restoration job on this bike so want the engine to be up together.

[wraith]

No you don't need to replace the piston rings when removed the barrels, and with the compression you say it has of 150 across all 4 cylinders that's not bad 

Yes them front drain tubes do look a bit bad but when/if you take the head off, you will need to remove them to replace the rubber oil rings on them.

On air cooled motor you always replaced the base gasket if you replace the head gasket or removed the head, not 100% on the oil cooled motors as they use a different type of gasket and the head and base gaskets can be resprayed and reused but until someone with more know says yes or no, I'd replace or respray and refit.

[Swiss Toni]

And those drain tubes will probably collapse when you try to twist them. Beware of rust falling into motor. Shove some small bits of rag as far down the tube as you can get them. Try to guage where the rag is, and cut the tube above this line. When cut, shove the rag further in, preferably to the case opening. Then try to get the tube out. 

[Jpich85]

Thanks everyone, I've decided it's probably best to give this a top end rebuild as it does look like it's had a lot of use and maybe not the best looked after, I don't think I'd be comfortable going any deeper like splitting the cases and checking over the crank and gearing, although I'd like to I just don't think I'd be able to do it, 

I'll get a gasket set and some new down tubes and fit them and I'll follow tyour tip @Swiss Toni

after looking at the price of piston rings I'm not sure if it's worth the money just to replace them for the heck of it. 

I've seen some people hone the barrels? Is that something I should do before refitting the pistons or is that for fitting new piston rings?

I'll relap the valves and check them over too and the cams.

[Jpich85]

4 hours ago, wraith said:

No you don't need to replace the piston rings when removed the barrels, and with the compression you say it has of 150 across all 4 cylinders that's not bad 

Yes them front drain tubes do look a bit bad but when/if you take the head off, you will need to remove them to replace the rubber oil rings on them.

On air cooled motor you always replaced the base gasket if you replace the head gasket or removed the head, not 100% on the oil cooled motors as they use a different type of gasket and the head and base gaskets can be resprayed and reused but until someone with more know says yes or no, I'd replace or respray and refit.

Thanks mate you boys gage helped me come up with a plan of action just hope no gremlins pop up afterwards lol

[wraith]

2 hours ago, Jpich85 said:

Thanks mate you boys gage helped me come up with a plan of action just hope no gremlins pop up afterwards lol

 there's always a gremlin hiding somewhere 

[Devilman]

2 hours ago, wraith said:

 there's always a gremlin hiding somewhere 

Only if you feed the Mogwai after midnight 

[wraith]

1 hour ago, Devilman said:

Only if you feed the Mogwai after midnight 

 or spill water on the Mogwai