Just Trashed my XS1100F

[xs1100newb]

Hello all,
I have sad news to report. Thanks to people on this site I have gotten my XS1100 completely functional. Everything was working well and the bike is in completely stock with original paint and exhaust in great condition.

I finally got the carburetor tuned today and got back from a short ride and decided to change out all of the spark plugs with new ones. The #3 spark plug was a real bear to get out (that should have been my warning to leave it alone). After finally removing it I noticed that there were metal shavings on the threads of the spark plug as well as in the spark plug hole. Someone really overtorqued that that spark plug. The threads are so bad I cannot get a new plug in the hole and I know for a fact that some aluminum metal shavings fell down into the hole.


I understand I could take the top end to a machine shop to fix the thread but that is out of my budget (especially since I would need a new head gasket) and out of my skill level. I am going to either sell the bike as is, or part it out. My understanding is the exhaust alone is worth some good money.



What do you guys suggest is a fair asking price? The bike is a 1979 XS1100F with original exhaust and paint. Minimal surface rust and it has approximately 40K miles. The bike runs like a charm (or atleast it did until this fiasco, but I am now to scared to turn over the engine)


Adam

[bikerphil]

Sorry to hear of your problem. You could vacuum the shavings out of the cylinder and use a Helicoil to fix the threads. Not too difficult. Don't have to take the head off for this. Good luck.

[James England]

I would definitely hoover the bits of thread out and then buy a 14mm helicoil kit on eBay. You can fit the helicoil without even taking the head off. It seems a shame to break the bike because of something simple like that?? You could have it fixed in less than an hour.

In the old days, riding Triumphs and Nortons, if the plug threads stripped we used to wrap aluminium baking foil round the plugs and tighten them back in! Then they invented helicoils and our problems were over....

[xs1100newb]

Can you be slighly more specific? Is there a special vacuum I need? Can the helicoil be done with the top not removed? Has this worked successfully for anyone in the past?

Adam

[bikerphil]

I'd use a wet vac to suck the shavings out. IIRC, they can be sucked out the exhaust port on the head. Someone who has done the Helicoil I'm sure will chime in with the specifics.

[xs1100newb]

Ok, so it seems that I can helicoil the thread and use a vacuum to get out the loose pieces of metal.


That is something I am willing to try, however, I just turned the engine over a couple of times with the electric start and there is almost no compression on that cylinder. I tested this by placing my thumb over the hole and turning over the engine. I could barely feel a thing! This makes me worried that the cylinder is already trashed. Is this a valid concern? I rode it earlier today and the cylinder was hot and firing.

Adam

[Rasputin]

I have never done the heli-coil repair. I have been told that if you want to do a plug repair on these aluminum heads you need a special heli-coil kit made for the application. The steel of the heli-coil and the aluminum expand at different rates when the engine is warm which can cause the normal kit to loosen. Just something to check out before buying any old 14mm thread replacement kit. It may be bunk but that is what I have been told.

[James England]

I would get a hoover extension tube and tape a piece of smaller diameter flexible tube to it... then stick it down the plughole and wiggle it about (with the hoover switched on of course!).

You should be able to do a helicoil with the engine in. Have a look on eBay... they often have instructions in the listings.

Re compression... the thumb test can be a bit unreliable... I've done it myself. A dry thumb gives a lower reading than a wet thumb! Not a reliable indicator. I mean... your bike was running fine... you devided to check the plugs routinely and not in response to any problem... the thread stripped as you undid it. That wouldn;t make anything cause lack of compression...

[natemoen]

A plain old drinking straw with the bendy head on it taped to any vacuum with good section will clean out the metal bits.

Here is a link to a kit (the plugs are 1.25 thread pitch right?)

[James England]

Try this.....

http://www.youtube.com/watch?v=vIVzE5cOWac&NR=1

or any of the other two thousand clips on uTube about helicoils!

[xs1100newb]

Ok, thanks guys. I am undecided if I will get a professional to do the helicoil or if it something I can tackle myself.

This is a damn shame. I have had the bike running for about two weeks now, but today was the first day I took it out for an extended drive and it performed lovely. I was very excited about this and I have hit this road block. I will keep you guys updated on what happens.


Adam

[cowboybob998]

red neck way

JB weld it if ya aint got no money it sure as h**l aint gona hurt nothing, did it on a chain saw onece and it worked.
How long had the bike sat befor you got it runing, the compression may come up after you get some miles on it when the rings seat back in

[xswilly]

its possible that a piece of shavings fromt the threads
has gotten lodged beteen the valve and where it seats
this would cause loss of compression
it could clear out once you get it running
or it could just stay jammed in there
may have to pull the head and pick the shaving out of there
helicoil it then do a correct compression test
with a gage
good luck

[Rasputin]

Somewhere on here fairly recently someone posted on how to rig a vacuum to blow into the cylinder while working on the spark plug hole to keep shavings, filings, etc from falling in there. I think it was Fredintoon that posted it. Probably a good thing to look into if you are going to do it yourself.

[ViperRon]

One more thing

One more thing to check. I have read your posts and even though this is a simple thing I have seen it happen before to people. Plugs usually have a washer on them I have seen these not on the plugs. Check the new plugs against the old plugs and make sure they are the same length from top of thread to tip of plug. If the plugs installed are longer you may have a concern. I had an uncle who was very unfamiliar with engines and when replacing plugs went to a store and got plugs. The plugs were not the same brand and were actually the wrong plugs and a bit longer. One plug had the washer missing. At first the bike had a hard time starting then made a tapping hissing noise when running. What had happened was the plug had hit the top of the piston cracking it causing loss of compression. My Uncle not knowing anything assumed the plug was not tight and then overtightend the plug damaging the threads. I told him I would help fix it but latter found he put JB weld in it and pawned it off on someone. I now avoid the uncle. The only suggestion is first check the plugs to make sure they are the correct length then use a compression guage to check the compression. Not trying to worry you but giving an explaination to the compression issue. If this is a bike you just got compression is something you should check.