New/old member here..

[harpo57]

Hi people! I'm Mark. I live in Spokane Wa. USA. I joined a couple of years ago. I finally acquired my first XS, a 79 special basket case. partially disassembled, burned hole in piston... So now I can be an active member! I look forward to seeking advice from the group. First order, fix engine! Any other members in Spokane Wa. area?

 

[robinc]

Welcome to the forum actively now Mark. Pics? We like pics. Any pics. We like pics of bikes. We like pics of parts, We like pics of piles of parts.

Good luck with your build!

 

[harpo57]

Welcome to the forum actively now Mark. Pics? We like pics. Any pics. We like pics of bikes. We like pics of parts, We like pics of piles of parts.

Good luck with your build!

 

[harpo57]

Hi Robinc! yes, I will work on pics... lol. And thank you for wishing me luck!

 

[harpo57]

Hi people! I'm Mark. I live in Spokane Wa. USA. I joined a couple of years ago. I finally acquired my first XS, a 79 special basket case. partially disassembled, burned hole in piston... So now I can be an active member! I look forward to seeking advice from the group. First order, fix engine! Any other members in Spokane Wa. area?

 

[harpo57]

,

Welcome to the forum actively now Mark. Pics? We like pics. Any pics. We like pics of bikes. We like pics of parts, We like pics of piles of parts.

Good luck with your build!

 

[TwoManyXS1Bs]

Anybody else see his front guide?

 

[azman857]

Now that you mention it... Oh my....It's NAKED!

 

[robinc]

Anybody else see his front guide?

Ruh-Roh, parts list is growing Mark. Ah well, you'd want to replace it anyways since you're in there.

 

[YamadudeXS650C]

You'll get plenty of advice here, Mark.
Good luck with the rebuild and welcome.

 

[gggGary]

Let me guess; 2 into one exhaust, stock jets in the carbs.
It's almost always the RH piston.

 

[Meddy]

Hi Mark, welcome to the forum.
I have a 79 special, also had the matching piston.

 

[harpo57]

Anybody else see his front guide?

Me... I see part of it... lol.

 

[harpo57]

Let me guess; 2 into one exhaust, stock jets in the carbs.
It's almost always the RH piston.

Stock exhaust. I havnt gone thru the box's of parts yet. Seller suspects an intake leak...

 

[grizld1]

Lean jetting might aggravate the mess, Gary, but I've only seen one XS650 motor with a holed piston that didn't show a worn timing governor with points set to the retard mark or a timing governor damaged because it came loose (and because the owner tried to "ride through" misfires and limp the bike home). Have a look under that right side ignition cover, harpo!

 

[harpo57]

You'll get plenty of advice here, Mark.
Good luck with the rebuild and welcome.

Thank you. Part sourcing/merchants advice welcome.

 

[harpo57]

Lean jetting might aggravate the mess, Gary, but I've only seen one XS650 motor with a holed piston that didn't show a worn timing governor with points set to the retard mark or a timing governor damaged because it came loose (and because the owner tried to "ride through" misfires and limp the bike home). Have a look under that right side ignition cover, harpo!

Ah.... timing gov.... In one of the part box's I hope.... or its hanging off the harness. seller said they replaced point set.... bad timing could be cause of damage huh?

 

[MaxPete]

Anybody else see his front guide?

Oooooohhhhhh....yahhhhhhh.

Harpo57 - your front timing chain guide has completely failed. There should be a plastic component bonded to that metal “shoe” - and so I would take a good look down into the sump and the area between the two cylinders for a chunk of plastic. (See photo below).

My guide failed in exactly the same way about 3 weeks ago (see thread entitled “Lucille pulls another one on me”). That missing piece of plastic will affect cam timing and therefore ignition timing. Would it be enough to burn a hole in a piston....I don’t know, but it sure wouldn’t help.

Anyhow - THAT, in addition to the piston itself needs to be addressed in your rebuild of the engine.

 

[harpo57]

Yup, its a basket case project. I received it disassembled. Box's of parts to go thru and inspect. New parts to order. Plenty to learn! It did come with a repair manual. Not having disassembled it myself, a challenging puzzle to put together.

 

[Paul Sutton]

Welcome Harpo57. I posted a note in another thread a few minutes back where you had shown a photo of your pistons. I then discovered this thread of yours so deleted my comment. I asked if the hole was melted or was it a crunch due to a foreign object getting into the cylinder? The edges of the hole just seem too sharp/thick for melting. Also, did you clean the top of the piston or did it self-clean due to overheating? I pointed out the issue with the guide but I see this has already been thrashed out.

Best of luck.