Disassemble the high part of the engine or not?

Operations with a disassembled cylinder head engine

Saga of the restoration of the sports car Kawasaki ZX6R 636 model 2002: 6th episode

But what is a tall engine? This is the part of the engine that includes the cylinder head (and its spark plug bore) with its distribution (intake and exhaust valves, shlags, pulleys) and the cylinders with their pistons. The tall engine takes care of the engine's energy management, between the distribution of the oxidizer and the fuel.

In our case, as we saw during our pre-purchase Kawasaki observation, spark plug # 1 is dead. Peace to his soul. Because the cylinder head provides high closing of the cylinder (s), the engine will not turn until it finds the missing cylinder. Shortly speaking. DIY Impossible: There is high pressure in the cylinder and you don’t laugh with pistons, spark plugs or explosions: you need a strong and durable one.

Defective spark plug good on Kawasaki

I am looking for the best solution for a good spark plug repair while continuing to move forward on the rest of the bike. From the beginning I know that repairs can be repaired by installing returned fillets or "insert" or "Helicoil" as they usually say. Of course, there is no need to operate the 636 engine with an open heart, given that a spark plug is repaired well without dismantling ... but the prospect of investing in this motorcycle, spending time caring for it, bringing it back to life and soul fascinates and delights me. Not knowing either the condition of the engine or its past, I said to myself: "Enough to check and do as much as possible!"

First lines of reflection on engine recovery

Option one: Replace the engine with a used engine or completely redo it

Some professionals offer complete repairs with measurement and replacement of worn parts. To do this, you must remove it from the frame, attach it to a pallet and send (or transport yourself) to the appropriate professional. The best solution for creating a new and good bow thruster that we can have confidence in. It even has to be a runaway. Amazing.

Awesome, but honestly not given, you can imagine it. The cost of the operation? From 1000 euros, to which any replacement parts must be added and, of course, the cost of "guarding" the motorcycle. Not to mention the "masculine" time it takes to get him out of his current home: the bike is complete (or nearly). It must also be prepared, packed and sent (by the operator, as it does not fit in the mailbox ...). Finally, “there are some who tried ... There were problems. Not to mention the period of about 1 month, introduced by the repairman. I found an engine between 636 and 450 euros with a mileage of less than 35 km. But I could not manage the logistics part in an optimized way and the cost was high again.

He complains very quickly in terms of cost and especially in terms of investment. So I quickly forget this decision, expecting to at least get rich. This does not prevent me from sharing with you the fruits of my investigations: spring motor pro: RC Engine (see catalog for details)

My goal is not to spend too much in order to get a good result and fully ride the motorcycle. In the absence of funding, I go to Plan B.

Second option: change the cylinder head to a new or used one

If you don't change the whole engine, you can change part of it. This is necessarily a much cheaper solution, whatever. There are Kawasaki ZX6 R and ZX6 R 636 cylinder heads on the internet from 2002 for about 90 euros. A little more in a case or used parts retail store. The chances of finding happiness for all motorcycle models are slim, and the condition and history of a part is never detailed. But when I did my research and made my choice, there was no more accessibility, no more equipment that is not really guaranteed or controlled, at least not available.

Buy full cylinder head

Cylinder head replacement cost:

• new cylinder head price: € 1
• used cylinder head price: € 100 to € 300 depending on the number of parts and the engine, but 636 are pretty rare.

With the natural pot I have (in addition to Gaston Lagaff, I am also called No Bowl, as in the movie Hot Shots), I avoid this solution in order to focus on the one that seems less expensive and most consistent to me: the setup insert / net inserted into the candle. In any case, replacing the cylinder head, as well as repairing it, involves the same thing, namely disassembling and reassembling a large part of the bike. Therefore, I choose "homemade". Finally, for being in the garage to attend. That leaves Plan C.

The third option is selected: so unload the entire upper engine to neatly re-thread the threads and establish a sustainable solution.

Therefore, this requires a complete disassembly of the top of the 4 cylinders.

Okay, this is serious. Anyway, I already planned to drain all the fluids on the motorcycle, whatever they might be. Therefore, the operation seems to me less expensive and less complicated than if it was carried out out of context. Moreover, the insert itself is the most economical solution.

Engine operations, cylinder head disassembled

Therefore, we can check and intervene in many important engine components. I feel like the renovation and fitness budget will be revised upwards! In a programme:

• Coolant cleaning
• Dismantling and serviceability of the radiator
• Dismantling and cleaning the exhaust line
• Dismantling the air box and cleaning the K&N air filter
• Removing the cylinder head and installing Helicoil
• Engine oil change
• Cleaning accessible and exposed parts (pistons, ...)

An already interesting list to which you can add without forcing too much and without much extra cost:

• Cleaning and operating the carburetor ramp and then adjusting after lifting the motorcycle
• Cleaning the valve and replacing the valve tail seal
• Valve clearance
• Checking the distribution chain and its tensioner
• Replacing the spark plug

And if I am not satisfied with the engine, I know that I will also have the bodywork, as well as cosmetics and general maintenance, including a brake purge and why not get it repaired, depending on what I see. There are parts for sand and repainting, elements, including ... a full body. And electricity is not up to the mark. The fork prompts me to clean her up and make her Spis, with her little lewd oozes. Finally, "grease". This is the advantage when the bike has almost everything to do: you never get bored.

On an adventure!

Getting into the big mechanic is an adventure in itself. Especially when, a priori, we have theoretical knowledge and practice, limited to classic motorcycle maintenance (stoves, brake cleanings, etc.). So, starting on a "big" 4-cylinder and attacking a liquid-cooled engine is sporty. Also, first of all, it is possible to obtain a good culture of the engine and, in particular, this engine. An engine that I don't know anything about. Of course, I wouldn't know the transmission's past, but I will be able to appreciate it, offer it a nice revision and a more definite future.

For me, a complete assessment of the real state of 636 is important: it is about my life, on the one hand, about the life of the engine, and then, and above all about financial investments, which, in my opinion, become more important than expected when my income is not planned to increase. I better understand ads like “sell a motorcycle for abandoning a project”, followed by succinct explanations of what it cost, trying to justify the often high selling price ...

In the end, I only paid “only” 700 euros for the bike and I think I’m willing to take the risk. While I'm doing this and while I'm crazy, I decide to open the Kawasaki curling shoe myself. I know I will curse for a little while, but that's it, I think I put my finger in it, as they say. Well, you have to know where to put it, exactly, your finger, which, let's face it, is not really my case. They say that the simple are blessed. I need to swim in happiness, I ...

I have two Bibles ZX6R 636: Revue Moto Technique in French and Workshop Manual in English, which I was able to get. I also have the entire knowledge base of a more erudite Internet than myself, including the Ladle Technical Forum and some specialized sites. With that, I feel ready!

Murphy's Law (Editor's note: Law of Maximum Appearance), you know? Well, we became friends with Murph 'during the implementation of this motorcycle rebuild ... Of course, I have not tested simple solutions. Not those who go through the dealer. On the other hand, I decided to carry out as many actions as possible and call on qualified craftsmen who specialize in the most difficult tasks. At least most of the time. Otherwise it would be too easy.