oil leaking from head/cylinder interface right above tensioner

[BA80]

This ain't my first rodeo. Just replace the gasket and torque it properly. And check your valve clearances while you're there. Perfect time to adjust any that need it.

I've seen MANY leaky valve cover gaskets do the very same thing and I've seen MANY people right here on this forum react just as you are. Including myself.

[clcorbin]

BA80,

I'm agreeing with you. Today, I get around to pressure washing the bike. Low and behold, as the "easy" to remove oil came off, what was left was the older, baked on stuff. And what I eventually got down to was baked on oil right around the second valve cover bolt from the left side (right above the #2 exhaust).

It was baked on to both the head side AND the valve cover side. There was a solid line of carbon about 1/8" wide from the seam straight down the head for about 1/2" or so. Pretty clear that THIS is were that oil is coming from.

So, when the gasket I ordered last week gets in, I SHOULD be able to get this little problem fixed.

Now to figure out what to do with the jetting. The process itself is pretty straight forward. It's the pulling and stabbing the carbs a half dozen times to get it right that scares the heck out of me!

[DiverRay]

The jetting is easy. Use the chart, and ONLY GENUINE MIKUNI JETS!! Do you still have the stock airbox? what exhaust do you have? How many turns out are you on the idle mixture? These three questions are the important ones. The big thing to remember is if you go up two sizes on mains, you need to go up one size on the pilot.

[clcorbin]

The jetting is easy. Use the chart, and ONLY GENUINE MIKUNI JETS!! Do you still have the stock airbox? what exhaust do you have? How many turns out are you on the idle mixture? These three questions are the important ones. The big thing to remember is if you go up two sizes on mains, you need to go up one size on the pilot.

Stock airbox
Kirker 4-1 exhaust (probably needs to be repacked again)
Right around 1-3/4 to 2 turns out on idle mixture

A biggie for me is I am in Albuquerque at 5200ft and it will be very rich with the stock getting. Right now I am one size down on mains and pilots and it is acting rich (still want to do the throttle chop test to verify WOT is rich).

I am half tempted to pull the header off and weld a bung into it so I can just use my wideband O2 on it. That removes a LOT of guess work.

[motoman]

Stock airbox
Kirker 4-1 exhaust (probably needs to be repacked again)
Right around 1-3/4 to 2 turns out on idle mixture

A biggie for me is I am in Albuquerque at 5200ft and it will be very rich with the stock getting. Right now I am one size down on mains and pilots and it is acting rich (still want to do the throttle chop test to verify WOT is rich).

I am half tempted to pull the header off and weld a bung into it so I can just use my wideband O2 on it. That removes a LOT of guess work.

....just a lttle rich, even with the 4into1. Elevation has little to no effect, least not much having the vacuum diaphrams. Mine was just fine at 6,500ft. elev. where I bought it new and road for some ten yrs with majority of riding at 10,00ft. and higher.with absolutely no adjustment nor jet change. I now live in G.Junction, which is some 4,800ft. elev........all stock intake and exhaust and runs fine with no noticed richness from plugs or otherwise.

[DiverRay]

Quick, dirty trick on the airbox may help. Remove the lower part of the box. Note that the air filter fits around an oval in the center of the bottom. Inside the oval is DIRTY AIR, and the CLEAN AIR is on the OUTSIDE of the filter.
Drill 4 1/2" holes in the CENTER of the bottom, inside the oval. This will suck in warm air off the engine part time, but it also allows more air flow. The Kirkers REALLY LIKE THIS!! When done, you should not need to change anything on the jets.
At sea level, '79/Kerker I was up 2 on mains, and 1 on pilot and it ran and sounded good.

[clcorbin]

I'm pretty sure it already has the holes drilled in the bottom of the airbox. It had the Kerker on it when I bought it in 89.

I'm off Friday, so I should have the time to do some testing and plug reading. Of course, I have a new AR that needs to be taken to the range for break-in and dialing in, so maybe it will have to wait until Saturday!

Of course, I am going to laugh and cry if I find out the mains are actually lean...

[clcorbin]

I did a hard, full throttle run up a decent hill today. At about 90 mph, I pulled the clutch and killed it. The plugs were all pretty much white. There was only a small amount of tan on them in the corners and I am pretty sure that is tan from idle and mid range.

Bigger main jets are definitely in order tomorrow.

My plans to change the valve cover gasket was hosed today. My sisters cats got on the table and decided the new gasket would be a perfect chew toy.

I was pissed.

As I didn't want oil dripping off my ankle after the test ride, I ran a thin bead of RTV ultra black on the seam of the valve cover gasket from the timing chain tunnel to the first screw on the outside. I had previously pressure washed it, so the metal was very clean and dry.

After the tests, the bike was still bone dry. At the very least, I now KNOW the valve cover gasket is the problem and even were it is leaking.

Just as soon as the NEW new gasket comes in...

[DiverRay]

I hope you only go up 1 size! If there was just a little tan, you are very close on the jet size. You DID check all 4, correct?

[BA80]

45 pilots and 140 mains work quite well in my 79 engine at this altitude.

Be sure and buy GENUINE Mikuni jets when you replace them or you will have tuning and running issues.