82 Seca 750 - Oil From Intake

My Seca has been out of commission for a year while it waited for me to fix a small electrical issue. I finally got that sorted out, changed out the old gas with new, gave it a check over to see if anything else was out of place, and started it up. Seemed to run fine, took it for a quick spin around the block, then put it up on the center stand and changed the front fork oil, which I've been meaning to do for a while.

Anyway, that went fine, and I took it down off the stand, started it up, revved the engine a bit to warm it up, and walked away. When I came back there was a puddle of oil dropping down, as far as I can tell, from the air intake area. Probably 1/2 - 3/4 cup of oil. My assumption was that it was just from how the bike had been tilted on the stand, much like my mower gets oil in the air intake if I tip it on it's side, and went out for a short test ride.

As best as I can see, this oil leak keeps happening every time I really rev up the engine. If I rev it up at a stop, it'll piss oil for a minute and then stop and be fine. I can't see the exact source of the leak, but like I said it appears to be coming from the air intake area, and there's a bit of oil under the air filter.

Any thoughts as to what my issue might be?

 

Issue ?? shut the bike off and hide the key !!

The most likely "issue" is gasoline in the crankcase
You are up against a carb re-build and a petcock re-build (search for it)
and an oil change.

You can't just keep running the bike - it needs some fixin !!

 

Either that or you overfilled it when you changed the oil.

If that's not the case, then the above advice is your answer.

 

while your riding that oil goes all over our back tire, that's never a good thing

 

Not planning on riding it anywhere else until I get the issue worked out.

Next best step then would be an oil change, make sure I put in the correct amount, and then run it again to see if it spits more oil?

 

Pull the line off the petcock and see if it drips

then - add 2' of clear line to the fuel line, tape it up vertically, and load it with gas. It should hold a level, not slowly go down.

 

First step would be to remove the oil filler cap, insert nose and have a whiff. If it smells strongly of gasoline, you got a carb-fueled overfill and need to fix the stuck float(s.)

 

Removed the oil cap and smelled, it doesn't seem to smell of gas. I haven't yet had a chance to try the gas-in-a-tube test, that will be next.

I did realize that I had forgotten to move the petcock from Prime to On while running the bike the day I was experiencing the problem, could that in some way have an impact?

 

If that is indeed what caused the issue then you DO have gas in the oil plus a stuck float or floats.

 

So the next stop would be here then - http://xjbikes.com/Forums/viewtopic/t=2908.html

 

Yep.

Followed by: http://www.xj4ever.com/setting%20fuel%20levels.pdf

Then: http://xjbikes.com/Forums/viewtopic/t=14827.html
With Part Deux: http://xjbikes.com/Forums/viewtopic/t=29209.html

And then a running vacuum sync (with the YICS blocked.)

Then, after making sure you check this: http://xjbikes.com/Forums/viewtopic/t=15874.html

And these, especially: http://xjbikes.com/Forums/viewtopic/t=41400.html

along with: http://xjbikes.com/Forums/viewtopic/t=41403.html

Then it should be rideable. If it does turn out that your "petrorooster" has issues, you'll need this: http://xjbikes.com/Forums/viewtopic/t=25058.html

Howzat?

 

Well. Looks like I might be able to get the bike back on the road before it's 40th birthday. Darn.

 

While I'm in there, are there any particular parts I should replace / upgrade during the process?

 

Stainless steel brake lines are a major improvement over the stock rubber ones.

 

The bike is currently failing the clear 3' tube test - drained 4 inches of the line in 10 minutes. Does that confirm the diagnosis?

Petcock is not leaking, so no problem there.

 

What's the best guide for a vacuum sync?

Rebuilding the carb actually went really smoothly. Parts organization, taking my time and no only running into stuck bolts when I tried to take out the bowl drain screws, which someone stripped before I owned the bike. A drill and my screw remover made short work of that and replacements are on the way. Overall, a good experience, let's hope the rest goes that easily.

 

you admins should sticky this or move to FAQ suggestions.....

 

Got in some new parts to go with the carb rebuild (like new gaskets since mine were destroyed) including some nice new chrome. As I went to post this picture this morning, however, I realized I made one stupid mistake. Can anyone spot it? I certainly got a good laugh out of it. - http://cl.ly/image/1Q3z40362o0h

 

Just measured my float levels - 2mm 2mm 3mm 0mm. I can guess which one might be the problem.

 

Ok, so here's a question, post-new-shims my valve clearances look like this-

Intake - .127 - .152 - .178 - .152
Exhaust - .203 - .178 - .178 - .178

Most of those look fine to me, and the ones that are just slightly high should wear their way into the middle of spec over time, but that .178 on Intake #3 worries me a bit. That valve was a .102 before replacement, and I measured twice to be sure, so I assume that the original shim was worn down, so moving up .05mm with a new shim was in reality a larger move if that original shim was out of spec.

Should I be worried about that valve having .025mm too large a gap?

 

I'd swap it if I were you. You don't want the cam to spit out your shim destroying everything it touches 8O

 

It seems you forgot a spring on your work bench.

 

That reminds me of the gags that guys in the shop would pull on each-other.

One afternoon, after watching a Master Tech do an MGB Clutch in world-record time ... we put a pair of new Throwout Bearing Retainers under the cardboard box the clutch came in.

When he cleaned-up and found the clips; he nearly fainted.

 

Darn, was really hoping to get the bike back on the road over the long weekend, and now I'll have to wait for a new shim to come in before I can vacuum sync and color tune.

And yeah, that's what I forgot when I first re-assembled. Got all the carbs back together and took that picture, then came into the house and was looking at it and realized one of the springs didn't make it into a carb. Much easier than a throwout bearing retainer to fix though!