Need a engine!!!

[GLoweVA]

Edit: It was #4 piston.
Here's the thread documenting my head removal and the jugs to get at the piston.
http://www.xs11.com/forum/showthread.php?t=33964

This is what I found after I got the head off.

[crazy steve]

I talked with andres and I guess I'm going to try and tear my motor down....

Check the valves before you rip it apart; if you don't know when they were last adjusted, that may be the whole problem...

[DRedel]

I had the mechanic and he knew what he was doing with olderjap bikes but not necessarily the xs11 although he has the book for it in his garage. He took the top off and checked the valves. He said that they were all inspec except one but he dident have the right shims. But he said it wasn't that bad. I made peice today with the fact that I'm just gonna man up and fix it myself. With the form to help me I'm sure I can do it. I can't make it at worse than it already is. I'll make sure to check the valves before I go any further tho.

[natemoen]

Valves and what is your compression?

[GTXS1100]

Edit: It was #4 piston.
Here's the thread documenting my head removal and the jugs to get at the piston.
http://www.xs11.com/forum/showthread.php?t=33964

This is what I found after I got the head off.

Ahh Ive seen that before. Thats what number 3 looked like on my bike. It was that way when i bought it. Guy told me it had carb issues. Obviously i didnt know that the guy screwed me till it burnded all the oil out of it and locked up on me goin down the road. Found a used motor and the rest is history. Good luck on your rebuild im sure there is enough help here to ensure a success.

[psycoreefer]

GTXS1100 and GLoweVA, did you guys both have 81 model year motors?

I'm only asking because if it is I've now seen and heard of 3 melted pistons all on 81's... and I've not seen anyone post of melted pistons on earlier years (that I've read or remember). Just wondering if there is a pattern emerging, maybe based on the leaner jetting as EPA regs cracked down on emissions???

When mine burnt it was in 100+ heat in south central CA in the middle of a road trip, bike was otherwise running great.

[cywelchjr]

I don't know, I thought the 80 and 81's were jetted the same, but only having an 80 I could be wrong. I've got an 81 engine in mine, but the carbs are 80 carbs with everything else being from 80.

[GTXS1100]

Mine is an 80G and now i have the motor from a 79SF. Couldnt tell you what caused it. Just the luck of the draw i guess. Luckly i was able to pick up a motor for 25 bucks from Bob Jones's shop when they were cleaning it out.

[ViperRon]

For things to look for in doing that type damage. Original cam chain adjuster. Valves sticking or adjusted incorrectly. Incorrect plug installed or the washer left off. Carbon buildup. heads shaved and not enough clearance. Red line overrevs. Weak broken valve springs. And my most favorite running too lean. Nitros has a habit of doing these things too.

I did know an idiot once that put a screwdriver in the spark plug hole at one time on another bike to break a bolt loose.

All you need is a little crack some heat and time.


Make sure to check the guides for buildup. When worn with bad seals they can get build up and cause a valve to stick or lag closing and just one time is all it takes

[BA80]

Those melted pistons are caused by running too lean. Carburetor issues.

[GLoweVA]

Mine was caused by running way too lean on only 2 cylinders for an entire ride home from work in the rain. I found out that I had a pick up coil issue and 2 + 3 went out and I was on the interstate and limped it home at WOT for about 25miles. #4 was just a little leaner than #1 and by the time I got home it was DONE/TOAST!

The obvious symptoms thou were NO compression on that cylinder and pressure build up in the crankcase that blew out a cam cover plug.