Repair the thread or candle well
Content
Fillet or spiral stacking
Methods and costs
When working on a motorcycle, a biker is never safe from finding a damaged or faulty filament unless he has generated it himself by tightening the spark plug too tightly. Because it is the fragile alum head that welcomes the candle. And when the key spins on its own, that is a really bad sign, and especially a sign that the thread is dead. Peace to his soul.
This becomes very problematic and difficult when these threads touch the crankcase or cylinder head as our example of a defective spark plug.
Inserted spiral polo or fillet, double intermediate thread:
Placing fillets or bulk foil in a candle well is the best option.
I take the opportunity to quickly update Helicoil (insert name created by eponymous brand) or insert mate or insert. Thus, "Helicoil" is a double intermediate thread.
Inside the insert mesh, the thread is compatible with the candle thread. Outside, the thread to the thread diameter is made directly into the cylinder head. This allows the insert to be screwed using the provided tool.
There are several types of faucets, including the threaded rod, which seems to be the most suitable: it mechanically lifts the markings when performing the counter-rotating rotational motion required for threading.
Using the insert, screw in until 2 candle grids (2 "lines") appear, break the ergot with the appropriate tool and lift the candle to a new place. We find a stronger thread that allows you to enjoy your new bike. Perfect repair and, above all, an additional guarantee that the motorcycle will maintain distance and impact.
Now it remains to be seen whether we do this without or with disassembling the engine, and whether we risk doing it ourselves or go through a professional.
1. Without disassembling the engine, taking into account the risks (slime, well at an angle)
Repairs are risky. You do not need to be mechanically jammed to think that usually pieces of alloy in a round and welded tubular enclosed space, swept away by a piston, and all this in an explosive environment where the temperature and pressure are very high, they do not mix well. Solution?
Get it done by a pro:
Now you must find it! According to our research, Luc Moto, a dealer in the Paris region, had a mechanic capable of performing the operation. Not everyone dares to maneuver. Only a few operators can install an insert containing a new stream without risking (too much). The repairs are priced at around € 100 and you should be able to bring your non-rolling motorcycle to the garage.
If you know this type of repair and have good addresses where to do this service, your testimony is appreciated. Quality and highly competent professionals are a valuable commodity, as is good advice.
In the comments to the restoration saga of our Kawazaki Zx6r "1364" shared his experience. So I come back here commenting. Thanks to him.
My uncle, a car garage, performed an operation similar to the one I was considering. After raising the piston to a highly neutral neutral phase distribution (adjustable from the crankshaft), it attacked the rattling of the well after covering the greasy tool. The fat keeps the chips in Gujur, which is quite reassuring.
It is also possible to create a "sterile field" in the operating room, with a rag surrounding the area we will be working on to avoid getting into it. This has yet to be clearly seen, so good light is essential. The hole inspection performed allows you to see if everything is going well.
For my part, I have a small remote endoscope type camera. It also features dimmable LED intensity lighting. I connect it to your choice on a tablet or smartphone and look where no eye has ever set foot. I found it for 8 euros at Action.
We blow as much as possible into the chamber to get any chips out of the cylinder. Of course, since the cylinder head is often made of aluminum, you cannot magnetize the boot. On the other hand, with chamber + rod + fat, it makes an effective and well-controlled combining agent, and I imagine we can get possible residues. After cleaning the new faucet with solvent, the spark plug base diameter insert can be crimped, accompanied, sealed with high temperature thread brake or roller glue.
Not bad at all, it is! The most difficult thing is to find a stop in the network so that it does not protrude too much into the cylinder head. It is possible to connect the insert to the mentioned old plug before installing the new one.
Do it yourself with the Tim-Sert system
The American system makes it very easy to remodel a candle well (among other things). All without dismantling. This is Tim (product and trademark) certification. The link is in the directory at the bottom of the article. A thorough operation, but a priori simple and risk-free. We haven't had a chance to test this yet. On the other hand, the kit costs at least 110 euros, just as expensive as its made by a professional.
2. Having disassembled the engine
Disassembling the entire upper engine and cylinder head to easily perform this repair may not be worthwhile, but if it happens during a global motorcycle restoration, it is a good option.
Do it yourself by disassembling the engine head and cylinder
Once the cylinder head is open, we use the same insert / Helicoil self-insertion tool kits, but no longer take the same risk. Indeed, for example, you cannot discard files in the rest of the engine.
It takes from 40 euros for a kit with all the necessary tools.
Take your cylinder head to a professional
You can also walk through a pro by bringing the cylinder head to the garage (easier than moving the motorcycle to restaurants) for around € 30. There are garages specializing in this type of operation (see catalog)
Given the small difference in price between the two options, why deprive yourself of a professional?
This is the option we chose when repairing the spark plug on our Kawasaki ZX6R.
Budget:
- Repair cost: from 100 euros for the installed pro cylinder head, from 30 euros for the professional, disassembled cylinder head.
- Set price: 40 euros.
Tools:
Faucet and professional (or kit)
