have a mild possible serious problems with my jugs.

[Zombis]

So about 2 weeks I was cruising my 1980 XS, put about 150 miles on it for the first time since i bought it. I was pretty stoked on life and it was one of the first days that it stopped raining. pretty happy about it although it was ticking way louder than normal. When I mean louder than normal I mean it sounded louder than the exhaust, which was fairly unnerving. Got it home that night and reved the engine, not high just to like 4000 rpms in neutral reved it one more time and PING PING PING and then the engine died. tried to kick it over once and it sounded like a gurgle. effing $hit nuggets... pulled the spark plugs and turned the rotor over by hand once....

The intake valve on cylinder 2 was stuck wide open

Drained the oil, let it cool down over night and pulled the engine the following morning. After I pulled the tappet covers i found that the valve retainer exploded, dropped a valve, bent it all to hell; pulled the head valve gasket was toast, pulled the jug and noticed that the base gasket was torn in a couple spots. Piston didn't look bad just two small ding marks.

noticed something a little odd on the #2 jug above the the highest point along the head gasket area. There is a dent almost a chip in the cylinder sleeve. catches my fingernail and sits higher than any other spot on the jug/ head gasket surface.

I'm thinking it's going to need a new sleeve what do you guys think? or at least a used jug. I'll post some pictures later tonight and show all of you folks and see what you guys think.

stay tuned

 

[shotgunjoe]

Would help to 'SEE' what you are asking about.

 

[kopcicle]

Every time I did something like that there wasn't enough left to diagnose the cause .

~kop

 

[Zombis]

 

[kopcicle]

Stone the top . Rigid hone (lightly) the bore . Check valve guides for cracks . Examine all rockers for abuse and wear . Toss all retainers and keepers in the bin . Carefully examine the guide bores and valve stems for galling . Once all damage is corrected assemble with 60% molly loaded lube/grease and correct clearances .

either that or kick rocks :-/ . You got off easy . As I said I usually cut them in half or something equally as exciting .

~kop

 

[Zombis]

 

[Zombis]

stone the top? like with a hammer? or like a oilstone?

 

[Zombis]

but yeah the intake valve guide has like 4 cracks in it. so that def needs to be replaced. do you just drive them out with the special tool/reamer and a hammer? All of this really set me back and with my current job funds are limited so this rebuild is going to take quite some time.

anyone have any idea what causes valve spring retainers to shatter? I really dont want this to happen again.

 

[shotgunjoe]

Guides are easy to remove, you will find a good write up on doing this.

Shatter like that? RPM's? Valve lash too tight?

 

[XSLeo]

Generally when the term stone is used, that don't mean hit with a hammer. The stone you use to sharpen your knife with will work fine.
If some one suggests hitting with a hammer the term usually used is peen. As in "use a small ball peen hammer to peen the pins on the camchain master link."
Leo

 

[mouser]

I dropped a large hammer onto my cylinder once and it made a dent in the edge twice that size in roughly the same place. It was high both on top and inside the bore. I took a three stone hone in a drill and made a few passes until the bore was nicely crosshatched and the high spot was gone. Then I took a sheet of 220g emery and stuck it on an absolutely flat cast iron drill press table and by doing small figure 8's and turning the head 1/4 turn after each pass I was able to remove the high spot. Then with a tiny half round file I cleaned up the little chamfer on the edge. It was fine after that.
I replaced valve guides once and was able to drift them out of the head easily after a good soak in kerosene. Then I put the head in the oven for 1/2 hour at 200-250 and put my new guides in the deep freezer for the same time. They went in easily. they are good to this day...seems to me I used a deep socket that fit over the guide and onto the little lip of the guide made sure they were going strait in and tapped them in in a couple of blows from a plastic hammer.
The drift I used to remove them we made on a metal lathe Smaller than the outside of the guide with a one inch end turned down to the inside diameter of the guide.

 

[Grinder]

Maybe a plastic surgeon could help. They do wonders with jugs!! somebody had to say it.

 

[Zombis]

plastic surgeons... lol

So i ended up taking the jugs to a machine shop to see what they had to say. The local machine shop is kind of expensive like $200 to hone 2 cylinders. when i was about to leave there was a pretty cool guy there that told me i should just take a rigid hone through the cylinder and very carefully take a file and some emery paper to the top.

Done.

checked the end ring gap on the new rings and everything is to spec. only thing is when i ordered everything from mikes I forgot to get new piston clips and the gasket kit that yamaha sold me didnt have valve stem seals... so now I'm playing the waiting game with mikes xs. Next time I'm totally ordering from a company that has business hours in the pacific time zone.

my next hurdle is trying to get the cracked valve guide out of the head and properly peening the new cam chain back together. At this rate I may have the bike back together by the end of this summer : (

I was reading something on here about using a oven to heat the head to like 200 degrees ? is this safe to do? or can it warp the head?

 

[jayel]

normal operating temp will reach 240+ easy

 

[pcoumbe]

when you heat the head in the oven, the whole component is heated uniformly so no problem with distorting. Good advice, and remember to freeze the guides also

 

[pcoumbe]

Also forgot to mention, I've got a problem with my jugs also, new baby and can't seem to get my hands on em

 

[Punkskalar]

I had the same damage in my first rephased XS650 engine, running way to high of RPM's, I split the valve collar, dropped a valve and did the same damage you are looking at. New valve, guide, and springs/hat and its been running for 18K more miles since...

 

[mrriggs]

Check that piston for side clearance on the rings. I tore down an engine with a bent valve and the top ring land was bent down, pinching the top ring.

 

[1974jh5]

Stick the locating dowels in the top of the jug then lay the old head gasket on them, look to see if the ding is in the part covered by the HG. If it is, hmm I'd be concerned about poor sealing. Even .004 or so will give combustion gases a spot to 'blowtorch' their way out. Use an old HG because on a new one the metal 'fire ring' hasn't been compressed and will cover a different area than an old one. If it doesn't touch the HG I'd just, as everyone says, stone out the mark carefully and button it back up.

Cylinder sleeves aren't hard to replace. Sounds scary but it's not hard, I've done them by sticking the new sleeve in the freezer overnight, then heating the aluminum 'block' with a torch till the old sleeve slides out. You need to slide the new sleeve in immediately and then let the whole thing cool. If it doesn't get all the way in immediately, no biggie. Just warm the aluminum with the torch again till the sleeve slides all the way in.

mrriggs is right, check that piston's lands to make sure the rings can be turned easily by hand. If it clamps the ring in place, you'll have blowby problems.

 

[scabber]

I split one in half like Punskalar. Well over 7500 RPM my guess valve float was the cause. I went with a new set of springs from RD and Alum. retainers, #1 cam hoos racing. No more high RPM For me.