Oil leak - New head gasket?

[Snow]

Oil is leaking pretty badly (seeping) in the area circled in red. Does this mean I need to replace the head gasket?

Btw, this is on Nina, my 'new' E model. I just got her running and close to road ready, but I certainly can't ride her with a leak this bad.

[TopCatGr58]

Hey Snow,

Congrats on getting your fingers on "Sticky"....aka Nina!!

Hate to ask, but have you checked the torque on that lower nut, should be 14 ft/lbs? That area as you should now know after splitting your cases is not a high pressure area, just being flung from the cam chain. Have you checked and retorqued the other head nuts, or checked the compression?? If it's good, then you might just try putting some oil resistant sealant all around that area to try to get it sealed.....not necessarily RTV!
T.C.

[Snow]

Yes, the first thing I did was check torque on the nut.

I went ahead and pulled the head and replaced the headgasket as I had a spare from a complete kit I had gotten for my other bike that I don't need (she gets the big bore cometic).

When I got the head off I could see that the two parts that stick out on the gasket were not in one piece. I'm not sure if that happened while I was taking it apart or if that is the cause of the oil leak, but it doesn't matter.

To be on the safe side (and hopefully I didn't mess myself up), after carefully removing all traces of gasket using a razor blade, I put a very thin bead of Yamabond 4 around the cam valley on the cylinder side including where those two "lower" head bolts go.

I had previously done a compression check and it came out:
140
125
140
140

After I get the cam timing set tomorrow, I'll go ahead and do another check just for giggles. Hopefully the Yamabond won't cause any leaks.

[TopCatGr58]

Well,

I didn't know you had a spare gasket, that's make it easy!

Yamabond is great stuff, I used it to seal my SOFA after putting the O-ring groove in it, seemed to have worked so far!!

Since you had the head off, you should have done a valve lapping to help insure a good top end seal, that way any low value of compression could then be attributed to the rings!? But I can understand your urgency to get it back together and on the road ASAP since your previous main ride is still getting itself together!
T.C.

[Snow]

I'm glad *someone* understands! It's been 3 months since I began tearing Maya down... it has been worse than cigarette withdrawal!

I kinda assumed ( uh oh, there I go again...) that Dave may have done lapping when he replaced the valves after she threw her cam chain way back when, so didn't think much of it. If she has compression/leakdown problems, I'll definitely look into that after I get Maya up...learned my lesson about not having a spare running bike

So far I've *very* impressed with the Yamabond - I used it a couple days ago to put Nina's tensioner gasket on (I put it on with just gasket and it leaked oil) and tonight it just simply popped off with gasket fully intact!

[mro]

Nina, my 'new' E model

couldn't but help notice the aftermarket headers with the custom spacer on number three cylinder

mro
btw
do they come in that red/brown color stock???

[Snow]

Heh, you do what you gotta do to close up exhaust leaks Those "spacers" actually came with the exhaust bolts in a little clear plastic container

[Snow]

New headgasket seems to have done the trick - no more oil leak. Also, I ran a compression check again after replacing the hg. Here's the original numbers:

140
125
140
140

Here's with a new hg:
170
170
180
165

Guess the hg was damaged!

Now to change my rear inner tube (just got back from a run to the Yamaha dealer - only place open past 3pm on Saturday)

[mro]

compressed

First set of numbers are close to stock.
Second sounds like you could have a "big bore kit"


mro
btw
While I would not re-use a head gasket on a customers machine, have used em a few times on engines that were mine when the gasket looked in good shape. I always spray a thin coat of copper on em first which will helps them seal.

[HobbyMan]

If get about 155 all the way across on mine after letting it sit a few days.

[Snow]

Btw, this bike had a hone and ring job about 2,000 miles ago IIRC if that makes a difference