Plug thread timesert came out twice!

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auldblue

auldblue

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Plug thread timesert came out twice!


Lost my second plug thread timesert after only 150 miles, what's up and how to keep it in!
 
Now that you have tapped it for the timesert I think it is too late to go for the Heli-Coil. When you put the new timesert in place make sure that both the timesert and the threads in the head are absolutely clean. Brake Clean should do the trick. I would dry them both with a heat gun before applying maximum strength (Red) locktite. Make sure the locktite gets on the whole thread. I would even put a couple of drops on the internal thread of the head. Now, screw the timesert in firmly. Put a spark plug into it with anti-seize on the plug. Snug the plug down in order to "pull" the timesert up toward the top of the thread. By doing this you are making sure that the timesert is in metal to metal contact with the thread in the head rather than having locktite on both sides of the thread. Let the locktite harden over night. You can check your work by taking the plug out and seeing that the timesert stays in place or you can just torque the plug down to full torque and go for a ride.
 
motorson said:
snipped before applying maximum strength (Red) locktite. Make sure the locktite gets on the whole thread. I would even put a couple of drops on the internal thread of the head. snipped
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That looks like a spark plug repair insert? Am I correct? If so, you need to use Loctite 2620 ultra high heat red loctite. I know from past experience [CHT gauge on a Mk III], that this area can easily reach 450 degrees F when running flat out. Most Loctite products are only good to about 400 F. The one linked below is rated to 650F See

http://na.henkel-adhesives.com/adhesives/product-search-1554.htm?nodeid=8797948444673
 
Cheers guys I checked the 2620 out after reading motor sons comment , I am going to give it a shot as I've nothing to lose now. Why has the timesert broken up at the end?
 
auldblue said:
Cheers guys I checked the 2620 out after reading motor sons comment , I am going to give it a shot as I've nothing to lose now. Why has the timesert broken up at the end?
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Have you double checked to make sure the bottom of the TimeSert is not hanging down into the combustion chamber? The old one looks like the steel is eroded, possibly from the plugs' spark going next to it??? That could easily happen if the insert is to long.
 
chaztuna observation is why we need a village to keep up with Commandos.
Timesert or helicoil would fail in plug wall application, with nothing to seat on like a case stud thread. If not trimmed/counter sunk enough putting in plugs torq could screw repair into chamber to fry thin edges, then adhere to plug when twisted out. Alu, especially Commando head alloy losses its grip on life deep into metal grains surrounds after various traumas and melt temps. Might not be able to glue in repairs long term either. Btw rigid Timeserts are considered more robust than Helicoil springs.

If worse case, might consider filling threads with special rod then re thread in this harder material for the longer term next owner may give ya a nod on. I've done this to fractured primary case to be pleased, it wasn't in area that showed, as worked at treat but is rather darker tint than Norton frail castings.

https://www.youtube.com/results?search_query=muggyweld+super+alloy+5

https://www.muggyweld.com/?gclid=EAIaIQobChMI87T7qNGu2gIVHLjACh2vSQUWEAAYASAAEgIjMPD_BwE
 
I would contact Comnoz to ask if he has a bronze insert fix for plug threads.

BtW, Loctite is electrically nonconductive, thus its use might cause weak to no spark.

Slick
 
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If the repair piece is so loose fitting there's nil metal contact - space enough loctite will electrically insulate then a good thing if won't spark/start in that case or might blow plug out on the fly as things thermally expand. Wasn't it the Brits that said, in for a penny down for a pound?
 
Cheers guys, I think it's time to wrap a wet towel round my own head and jist send the bikes head to Norman White and get an insert made. A would like to go to the NOC red bull ring rally on this bike and there's no point in chancing it on a big run. I'll speak to him today and see if he can do it. The fact that it's came out twice does not fill me with confidence.
As for your comment Steve, down for a pound.....yer right!

Chaztuna, spark eroding the timesert , tried to get info from wurth the timesert suppliers ,they were poor and uninterested in the problem. I still would like to find a course for the missing bits on the 'cert as they are almost identical!
 
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The time sert is designed to be self locking.when you install it the the installation tool is supposed to go all the way till it gets easier to turn, at that point the insert will have expanded aganist the threads to form a permanent lock. IF THE INSERT IS TOO LONG IT WILL NOT LOCK INTO PLACE.

I have used these several times and they are superior to any wire insert.


Craig
 
74850 said:
The time sert is designed to be self locking.when you install it the the installation tool is supposed to go all the way till it gets easier to turn, at that point the insert will have expanded aganist the threads to form a permanent lock. IF THE INSERT IS TOO LONG IT WILL NOT LOCK INTO PLACE.

I have used these several times and they are superior to any wire insert.


Craig
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Except that when you use them on a Norton they come very close or even into the valve seat bore. I have worked on several heads where the valve seat came out after a crack developed between a thick walled plug insert and the valve seat bore. Jim
 
As Jim said, the insert can come pretty close to the intake valve seat. In heads with big valve conversions, you can get interference between the intake valve and a too long thread insert. I don't know if that can be an issue with stock valve sizes.

Ken
 
A few of us rode Nortons from Canada to the California border to attend the INOA rally in Ashland. We "allowed" a Triumph Tiger to come along. We camped in tents along the way, and every morning when we started the bikes, the Triumph would run badly on one cylinder, occasionally the second cylinder firing with loud explosions and flames shooting out the muffler. Sleeping children woke up crying and groggy parents stuck their heads out of their tents in disbelief. 2000 miles later, back in Canada, the Triumph owner found out that a helicoil for the sparkplug was loose and wouldn't ground until the engine was hot. I wonder what the parents had to say to those kids about British bikes.

Stephen Hill
 
Even if it doesn't go all the way into the seat here is the real danger. This head had not lost the seat -yet- but it came out with barely any pull. Some heads have the spark plug hole closer to the valve than others.
Plug thread timesert came out twice!
 
comnoz said:
Even if it doesn't go all the way into the seat here is the real danger. This head had not lost the seat -yet- but it came out with barely any pull. Some heads have the spark plug hole closer to the valve than others.
View attachment 4616
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Wow, that is close! So Jim, what repair is possible for a stripped plug thread?

Slick
 
texasSlick said:
Wow, that is close! So Jim, what repair is possible for a stripped plug thread?

Slick
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If I were needing a quick fix I would use a simple wire helicoil. Sometimes they do fail but at least the head is still easily fix-able. If the coil is installed correctly so that neither end of the coil comes all the way to the end of the hole they generally stay in and hold pretty well.

Otherwise the repair I do was designed to solve the cracking problem.

Once it has had a thick walled insert fail the only good fix is to remove the valve seat, weld up the area and machine a new bore for an oversized seat.

This gets expensive and unfortunately the head will never be the same again as the welding will anneal the aluminum to where it can not be brought back to it's original hardness.

On the head in the picture I made a threaded aluminum insert that screwed into the hole above the end of the crack. Then I milled out the crack and tapered the plug hole below the insert with a die grinder. Then I welded in the whole area and machined a new valve seat bore and spark plug hole.
 
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