HELP!! Spark plug insert to head stripped 82 GS850GL

[Guest]

The insert the spark plug goes into that goes into the Head stripped out. It’s stuck to the plug, I would have never noticed had i not washed the bike and saw exhaust come from the plug area. Anyone have a quick fix until I get another head in? Plug with a bigger base as a temp fix? Anyone have this happen?

[gordinho80]

Heli-coil maybe?

[Nessism]

The spark plugs thread directly into the head. No insert. If you bike has inserts it was done after the bike left the factory. Maybe someone tried the install an insert but it's failed?

You might want to post some good photos so we can see what's going on.

[Cipher]

I wonder what the prob is galvnic corrosion or a ridge of carbon that yanked the insert out?

[Blue Falcon]

Photo of plug and insert

[roeme]

Uh, maybe upload it to imgur or something in a higher resolution and size

[Cipher]

an hones to god insertwell cant you uses a double nut set uo to extricate the plug? Whats the writing on the insert say? Maybe not seted properly?

[Sandy]

I had one of those from the previous owner in my GS1000. It too sometimes would come out with the plug, sometimes not. I found a nut with the thread same as the outside of the insert, cut a slot across one of the flats and clamped it in a vice to remove the plug from the insert (PITA). Some sort of fine thread, forgot what size though. It too eventually ate away at the threads, probably galvanic corrosion as mentioned. It lasted long enough that I just replaced the head when I did my valve seals and rings a couple of years ago.

[Nessism]

It's hard to tell but that looks like one of those solid inserts like being sold at auto parts stores.

A Timesert is sort of similar except they are mechanically locked into the head using a setting/expansion tool during install.

At this point I think you will have to get that insert off the plug and reinstall it into the head. I'd use something like high temp retaining strength threadlocker. Or, see if you can find someone with a timesert tool and have one of those installed instead. Problem you may have is that the hole is larger now, so you gotta find a large size insert. A helicoil is off the table at this point.

[Blue Falcon]

Cylinder head side plug...... checking our autoshop to see if the have a 3/4-16 tap. The plan is to tap it out, use a smaller helicoil wire, heat up the helicoil wire wrap it around the insert pop some green loctite on it and see if it sticks to the wall until I get a new head.

First I am going to try a m19x1.5 tap to rethread and put a new head side plug in. It may just need a rethread....and some serious green loctite.

couldn't find the tap locally, ordered the plug and tap.

[roeme]

You gonna take off the the head for tapping? Or am I overestimating the risk of metal chips falling down into the cylinder?

[gsrick]

Chris said the machine shop will do it with the head on. I did it once on a Rebel 250 engine at MMI, but I don't have the tools for the job. You can fill the tap flutes with bearing grease to catch and grab the shavings, but there is still a risk of missing some.

[Nessism]

Cylinder head side plug...... checking our autoshop to see if the have a 3/4-16 tap. The plan is to tap it out, use a smaller helicoil wire, heat up the helicoil wire wrap it around the insert pop some green loctite on it and see if it sticks to the wall until I get a new head.

First I am going to try a m19x1.5 tap to rethread and put a new head side plug in. It may just need a rethread....and some serious green loctite.

couldn't find the tap locally, ordered the plug and tap.

Bad idea. Get a proper spark plug insert like the Timesert. The more you monkey with the hole and make it larger the bigger job it's going to be for the machine shop to fix it right.

[Blue Falcon]

Bad idea. Get a proper spark plug insert like the Timesert. The more you monkey with the hole and make it larger the bigger job it's going to be for the machine shop to fix it right.

Its going to the machine shop on Monday, 99% chance same day fix and the do it in place. No need to pull the head. “Cylinder head specialists”. According to them, it’s a very common problem on aluminum heads.