Yes... Another oil leak (sigh)

[lsc8]

Tracking down another oil leak. Pic below of the oil tube removed. Everything felt tight. Do these 2 small bolts do anything? Could they be leaking oil? Should the oil tube have any sealant on the npt thread? I have already retorqued the head bolts to 32 pds. Didn't want to go much more. Thanks!

 

[5twins]

Those two small bolts hold the front cam chain guide in place. They should have copper sealing washers under them I think, so should the larger chrome nuts under them. They thread into the aluminum guide so don't tighten them much past 7 ft/lbs. Did you have that motor apart? If not, I think it's due, lol. No sealer on the oil tube threads but do use two wrenches, one on the fitting in the engine, the other on the oil tube flange nut .....

And if you expect to get things to seal, you're going to have to clean that area up some. It's a real mess.

 

[lsc8]

Yea it needs cleaned up. Started trying to track down the oil leak before it got cold last fall and am just now getting back to it. I didn't see any copper washers under the 2 small bolts? Can I take these out 1 at a time without ill effect? Why is it you think the motor needs to come apart?

 

[5twins]

Well, if it turns out to be the base gasket, disassembly and replacement is about the only cure for that. I checked the parts diagram and, yes, it does indicate a sealing washer under those small bolts. In fact, Yamaha calls it a "gasket" not a washer. Unfortunately, they list it as obsolete which seems strange because it's still in use on models today. Yes, you could pull one bolt at a time and add the washer. If they really are missing, that could very well be the source of your leak(s).

 

[lsc8]

I would assume the base gasket requires engine removal? Do you know if this is a rubber or copper gasket? I could make something work I think.

 

[5twins]

It's a paper gasket and yes, engine removal from the frame is required. The studs that hold the cylinder block and head down are very long, extending right up through the top cover. There's no room above the motor to lift those parts up off the studs while it's in the frame .....

 

[lsc8]

Sorry I meant the gasket on the 2 small bolts. Thanks for all the help. I think you answer 90% of my questions.

 

[5twins]

Yamaha calls it a "gasket" but it's actually a copper washer like those used under many of the other case bolts. However, all of the others are larger, being used on M8 or M10 bolts or studs. You need to find some M6 copper washers, or maybe an American size close to that. Being copper, you could easily file the hole a little bigger if need be.

 

[lsc8]

Ok in town and will head to the hardware store or try to find a copper brake banjo bolt washer. There wasn't anything behind the bolt so maybe this will fix it. Funny it didn't leak before now.

 

[weekendrider]

The copper washer that go under the bolts are still available?
http://www.partzilla.com/parts/detail/yamaha/YP-90430-06014-00.html

 

[5twins]

Well, I would hope so since it's still used on current models, but boats.net says no. On some of these sites though, you don't know if something really is there until you put it in your cart and try to check-out.

 

[weekendrider]

Yes I was a little surprised that boats.net said no go.
Yamahas speed and sport site still lists it as available so I'd bet the dealer could supply it without having to order.
Like you noted it is used in a bunch of applications.

 

[5twins]

This is a handy size to have on hand because besides those two bolts up front, they are used on the 4 lower right side cover screws - and you often find some of those missing. I bit the bullet and sprung for a 50 pc. bag from McMaster-Carr. Cost me like $11 but hey, if you wanna play, you gotta pay, lol.

 

[lsc8]

$11 is better than driving around trying to find one.

 

[weekendrider]

Hell drill a hole ina penny and cut it down with dykes.
Nothing in lifes manual says a washer has to be round.

 

[lsc8]

Reread this for a torque spec and realized there were no copper washers on either small bolts or the chrome nuts they screw into. Cleaned up and new copper under both now. Hope that takes care of it and its not the base gasket. Thanks for all the help!