Crack in jug leaking oil

Argh! Just did a head gasket, adjusted the valves, cleaned it up and put it back together. My 82 xj650 looks and runs better, but it leaks oil like crazy now. There is a hairline crack in the jug, right in the front, that maybe was patched by a previous owner. Cleaning it must've unpatched it. I've tried a coat of JB Weld on the outside and while idling it seemed like it wasn't going to leak. But once I got on the road it leaked pretty bad.
I guess my options are
(1) to try with the JB Weld again - Anyone think it's a good idea? Is it worth it?
(2) find a new jug and take it apart again. Anyone have one to sell?
or (3) Is it possible a machine shop could weld it and look for other leaks?

Number 2 seems best to me, but I've always gotten such great advice on this forum, so I thought I'd see if anyone has any thoughts on the matter.
thanks in advance,
Scott

 

Replace the cylinder bank, it's not that tough.

 

^^ what he said ^^
But only if you can snag a set of jugs that don't need a rebore. The other option is to pull the jugs and have the crack professionally welded by an experienced shop. Welding would be the less expensive route if your replacement cylinders need machine work.

 

This. Cylinder jugs get really hot, and it's doubtful that any type of repair ---- jb weld or real weld --- would last all that long.

 

Thank you Len. I was kind of leaning toward that too. Makes the most sense. Time to hit EBay.

 

Phew,

Trust me, I know the difficulty of finding decent cylinder jugs. You'll want to make sure they're in service limits 63mm to 63.1mm,

Anyhow - ebay is a good bet. My cylinders in my engine were 63.14-63.17. I just purchased a set off of a 82' seca (non yics).

You're in luck however, I found significantly more YICS cylinder jugs than non-YICS, a much larger selection to choose from on Ebay.

 

Dude, what bike?

 

jmlliken it's an 82 xj650 Maxim. It's YICS. Maybe you think you have one? That'd be great!

Gulrok, thanks for that info. I was actually thinking after my initial post that I should ask that question.

 

The cylinders don't get hot enough to melt aluminum (under normal conditions). An experienced shop will be able to either prep it for welding (when done correctly the repair will be permanent) or tell you that it is beyond repair. I've seen cylinders, cases, and even heads that were been repaired by welding 30 and 40 years ago which are still in regular use.

 

Here's a question for more experienced mechanics/machinists; If these aluminum cylinder blocks have steel sleeves, does the crack have to penetrate all the way through to the cylinder in order to leak, or could this oil be coming from an oil passage inside the block moving oil from the case to the head? I guess it would help to know where the crack is?

 

The crack only needs to get from the outside to the inside for the oil to be able to leak out. If the crack is through the cylinder wall, that's a whole different solution- get a replacement cylinder block. The only thing that's in the cylinder block, other than the cylinders, is the oil. If there's a crack, the oil is gonna push through. Now, if you happen to have an X, then there is a water jacket as well..........in that, if you have a crack, it could be into the oil passages, or the water jacket, or crossing between the two, etc......

Dave F

 

It would be coming from an oil passage. There would also have to be a crack in the cylinder sleeve for the leak to come from there.

 

if the steel liner was cracked, you'd leak more than oil. the compression would come out and that would be obvious.
i'd find a used one and then try every sealer known to man, get the new one first, then once you have a spare you'll never need it........that's just how it works