retorqued head now Base gasket leaking

[ThatXS650Guy]

Ok. So I followed the advice from the board and re-torqued my head. It runs great but I have oil seeping/streaming from my base gasket. I may have screwed up when I took the head nuts off because I took the opportunity to replace the old rubber washers with brass washers and also to replace the upper mount with a HHB unit. There was about a week between when I took the old washers out and re-torqued the head.
Am I screwed? I've already re-torqued the head big nuts to 30 ft lbs a second time.

This is after riding about four miles.

 

[gggGary]

could be I have always done just one nut at time on retorques. Clean the oil off with some mineral spirits, dust it with some talc, start it and make SURE you know where the oil is coming from. Oil can run down from the cam chain tensioner area and LOOK LIKE it is leaking out the base gasket. Did you do the 2 bolts under the spark plugs?

 

[louis]

I had oil leaking from my cam chain tensioner gasket and it looked like your problem, check that, might not be the end of the world.

 

[ThatXS650Guy]

Ok, I'll clean it all off, re-tighten the cam chain tensioner and see what happens.
Thanks everyone.

 

[ThatXS650Guy]

Woo Hoo! It looks like the problem was the cam chain tensioner not tightened all the way. Started it and ran it on the stand for a few minutes and not a trace of oil. I'll take it out tonight when I get home to make sure before I head to the Dogwood Rally.
Thanks everyone.

 

[gggGary]

There is a single 6mm bolt on the head gasket that sits just above the tensioner, its the only fastener for a long thin strip of the gasket. You have to be VERY careful cause it's small and easily stripped and it's a bit hard to get to but make sure it is snug.

#11 NOTE: 7 foot pounds!

http://www.xs650.com/forum/showthread.php?t=2034

View attachment 62867

 

[650performance]

30 lbs. of torque isn't necessary and can cause distortion, which creates its own problems. On 750cc race engines you only need 27 - 28 lbs. Bud Aksland, who build KR's engines used a 1" long & 1/8" thick steel shim that fit between the fins under the head bolts to spread the load out and then torqued to 28 lbs. He told me that anything more than 28 without a shim could warp the casting, leading to any number of potential future problems.
Also, the stock studs are fairly soft steel. When torqued to more than 28 they can begin to stretch but, of course, won't do so evenly, so there's another potential source for more issues. A number of engine builders had studs made from higher quality steel, but that's overkill, especially for a non-race engine.
Bottom line: if the surfaces are flat and clean and the gasket is good quality you should never have to go over 26 lbs. on a stock engine.

 

[NorazDad]

30 lbs. of torque isn't necessary and can cause distortion, which creates its own problems. On 750cc race engines you only need 27 - 28 lbs. Bud Aksland, who build KR's engines used a 1" long & 1/8" thick steel shim that fit between the fins under the head bolts to spread the load out and then torqued to 28 lbs. He told me that anything more than 28 without a shim could warp the casting, leading to any number of potential future problems.
Also, the stock studs are fairly soft steel. When torqued to more than 28 they can begin to stretch but, of course, won't do so evenly, so there's another potential source for more issues. A number of engine builders had studs made from higher quality steel, but that's overkill, especially for a non-race engine.
Bottom line: if the surfaces are flat and clean and the gasket is good quality you should never have to go over 26 lbs. on a stock engine.

So I just did a top end: 650 kit from Mikes....pistons, rings, with gaskets, valves, seals and cam chain. Torqued to the board rec 30 ft lb and I am getting an oil leak at the base gasket. Can I loosen the head, let it rest and the re torque to 26? Or have I screwed the pooch and need to disassemble and reinstall a better gasket?
I guess I'll try it and if I'm still leaking, then I'll get a better gasket and re roque...
Or maybe the jug isn't perfectly matched to the old case...then in that case we need to see if they will eventually settle in, (mate)...or not.
I'm interested in any input.

 

[nj1639]

Yeah, you can loosen them all and retorque. There's three different torque settings as there are three different sized nuts/bolts so torque accordingly. Specs should be in the manual.
I recently retorqued a rebuilt that I had originally torqued the large acorns to thirty lbs. Had a leak right side front head gasket. Retorqued to the lower spec setting and so far so good.

 

[xjwmx]

Front oil pipe fitting leak will blow backward and look like a base gasket leak.

 

[NorazDad]

I have a lot to keep my eye on an it looks like a little hope.
Thanks

 

[NorazDad]

Ok, so I may have hijacked this thread thinking that I may have installed the base gasket incorrectly. Wrong. The oil was blow back drip down from the cam seal. I had no gasket and used permatex. Bad. Took XSLeo's advice and mounted it with a new o ring dry. That seems to have done the trick.
I did order a new seal and gasket. Hope the seal is not the three lipped devil. If it s, I'll send it back.
So far my top end is perky and idles dead on at 1200
I have accelerated to 65 but only for a moment still trying to seat the rings and such. So far so good. I like that there is no lag between getting on it and just cruising along.
Thanks for everyone's help
The learning curve is a constant
Peace, All!

 

[nj1639]

Ah yes, the old cam end seal. I'm doing a break in on this rebuilt engine in the '78. I saw some oil on the left side, fore of the spark plug. On further examination it was coming from the cam end seal, left side. I pulled the chrome cover off and discovered that I had missed tightening those three Phillips head screws. They were hand tight but not impact tight. One of the many reasons for having an impact driver is those three screws, whether taking them out or putting them in. I got the driver out and set them good, no more leaking.

 

[NorazDad]

Thanks for that input. I don't think I have the guts to impact them, but I did give them an armful.

 

[Chinooutlaw]

My 81 xs650 wasn't running for 7 yrs got her up n running and noticed oil leaking from bottom of jug on left side

 

[gggGary]

Well read the,thread do the retorque then follow the other suggestions let us know how it works out?