my Spark Plug popped outta of my 82 xj 650

That's right on my way to work at a stop light. My name is Jimmy and live in the burbs of Chicago.

Just a quick background I picked up the bike this past winter and it was in perfect shape. Tank is in perfect shape(no scratches no dents paint shines), the seat was just re-upholstered, 4-1 pipes, carb cleaning just done and complete tune up. I picked it up with 18K miles and have put on about 4K more since summer began. I've changed the oil twice since owning it and changed out the air filter. I pulled one of the plugs when I first got it and they looked good so I figured I would ride those out until the end of the summer.

The problem: For about a month I've been hearing some air coming out of the block/pipes/gaskets I didnt know where. But it would happen when I would first start the bike up and It would die down as I continued to drive it. I took it to two people I know that work on vintage bikes both told me it was nothing to worry about. Well while sitting at the stop light the spark plug popped out entirely out of the block, no harm was done to anything. I was able to pull into a gas station screw the plug back in by hand and drive it back a mile or so back home. Once there I got my wrench out and tightened it down to find out the threads in the block are stripped :x

Has this happened to anyone??? What are some options I have, how much do you think this will cost to fix? Any suggestions are greatly appreciated and sorry for the long post.

Jimmy

 

Retap your head, I would have a shop do it, if your not to mechanically inclined.

 

Agreed you can retap or if that fails you can install a helicoil. not a huge problem. You will have to take car not to get shavings down in your cylinder. There have been some threads on here where folks have done it.

 

Thanks for the reply gentleman and making me feel a little better about the situation. I would most certainly take it to a shop but what would you think would be a reasonable price to "retap"? It's the cylinder on the right-inner bank.

 

You can get helicoils or heilcoil like inserts that will do the job. (You drill out to a larger diameter, retap for an insert, then place the insert that has the correct internal thread for the sparkplug) The main problem is that you will probably have to pull the head to avoid the possibility of getting any metal flakes in the cylinder.

Here is an example http://www.sjdiscounttools.com/hel5334-14.html

I don't know if people on here know any tricks so that you don't have to pull the head but as far as I can tell there is no way around it as metal flakes in the cylinder are very bad. (Though a good shop might be able to pull this off)

If you pull the head you will need some new gaskets and such so I would recommend that you do a bunch of work on other things while your in there (lap the valves, replace valve seals, re-adjusting the shims afterwards, de-coke the head, inspect the cylinder walls).

As for tools (if you decide to get the helicoils and do the work yourself) you don't need too much besides a torque wrench, a manual, a 10, 12 and 14 mm set of sockets and wrenches. (more if you want to lap the valves). Time wise it takes me about 2 hours to remove the head and another 2 to reinstall, then about another 2 to get the carbs setup again. (Or if you dont pull the head it would probably about 30 minutes and just the helicoils - I just don't know how you, or the shop, would avoid getting metal flakes in the cylinder).

 

You can pull the exhaust pipe and replace it with the end of your shop-vac hose; make sure the piston is at the bottom of the stroke, and the throttles open, and turn on the vac during the process.

Or, you can pull the exhaust pipe, be sure the piston is all the way down, and stuff a lightly-oiled rag in on top of the piston. When you're finished, use your shop vac to suck out the rag and the shavings it captured.

 

Suggest you demand and pay for a Threaded insert (wurth?) rather than a helicoil. A whole different league 'better' long term fix.. and Should be the same cost. G'luck

 

ok well just got back from camping this weekend and I'm getting ready to take my bike over to the shop. Would you guys think I could drive it there? It's about 4 miles from my house, or would you recommend I haul it there?

 

Heres some info if you do it yourself - its not that bad really.


http://xjbikes.com/Forums/viewtopic/p=1 ... tml#127838

 

From what I can see, the only advantage to a threaded insert is "easier" installation. There is nothing wrong with the longevity of standard helicoils. Many people have used them as a one time long term fix. We even used them somewhat regularly on helicopters when I was in the Marine Corps. They saved us from having to change or scrap major components on a few occasions.

 

Problem fixed!

My buddy went in thru the carbs to stop any shavings from going down into the motor. And while in there he cleaned out my carbs.

thanks for all the advice!

 

glad to see you are back up!