TOPIC:

Thought I would give you an update on where I am at with my bike. As previously stated in another post I finally got my bike on the road, but unfortunately this was short lived . If you recall my bike had been sitting for some substantial time before I obtained it and started my restoration. At the time I took a punt on the engine, albeit knowing deep down what the likely result would be.
I managed to get three relatively short rides on her before she started blowing blue.
The sitting and probable rust build up has taken it's toll. Compression test results in two cylinders at 120psi and the rest around the 80-90psi.
Now my dilemma is how far do I take the engine reconditioning.
At this stage I have not removed the head or barrels so am not sure the full extent of any wear etc.
So the question I am asking myself is how far do I go with the rebuild.
Do I stick with just doing the top end, either rings and honing if the wear is not excessive and within tolerance, rebore and new pistons and rings, or go the whole hog and replace everything, finances allowing.
Thoughts......

Also, where is the best place to get engine parts from at a reasonable price. I have seen the big bore kits on ebay ( have read some posts on these ) and have checked out the supply of parts on Z1300.de, which is quite expensive. Also checked Zed-parts and zpower, but they have limited parts available.
Are there any other places you guys can suggest.

Thanks in advance.......again

I think most of us have come to the same situation you have - and it is indeed a big question because the cost is substantial.
And here in North America anyway , the chance of getting more than 20c on the dollar should we decide to sell is a big loss.
So the first question for me was , do I really like this bike enough, to justify spending what ever was necessary to get it to run right.
The answer in my case was yes.
The fix. If the bike is only ridden ocassionally then a hone of the cylinder bores, providing the rust isn't too deep, my suffice .
Do you want to stay close to original bore size or if that doesn't matter, then the big bore kit from Japan is the cheapest option.
First and second size over, parts are at the german store , or on the south african site.
And once the head and barrels are removed, then valves, guides and valve seals should be done. And the cost is going to be around $2000.00 if you do the work yourself. No small investment. There is a lot to this engine- it is more complicated than just about any other bike of this vintage because it is a 6 cylinder. That said, everything you need is available -albeit at a price.
If you are unsure where your smoking problem is coming from and want to get a better handle on just what you maybe in for, then do a leak down test first. Kawboy spoke about this a week or so ago.
And then somewhere reasoanbly comfortable to do the work.
This project may take awhie.

Thanks tacklehappy, you have pretty much confirmed my thoughts. I love this bike and have invested much into it, not just money, but time and effort.
To me it is worth every penny.
I guess once I get her apart I will have a better handle on what is required.

Ok, the first question, How long have you had the bike and when was the last time you rode it? Reason I ask, the early 1300's had an oil burning issue related to oval cylinders and there was a tech bulletin put out and SOME of the 1300's got a cylinder honing and new pistons aux gratis (warranty). IF that hasn't been done then a precision hone and a new set of rings may be just the trick. Don't waste your time and money on those 3 fingered hones. You need to hone the cylinders round and a 3 fingered hone will do nothing more than deglaze a cylinder. Most piston rings are cast steel with a chromium finish and won't seal worth a dam if the cylinder is not round. A precision hone (Sunnen comes to mind) is the ONLY way to go. If the bores are outside of the service limit then a cylinder bore and precision hone will be necessary. (plus pistons)

I've been toying with the idea of buying the set of pistons on Fleebay which are the 64mm overbore set at $250.00 U.S. and I'm leary of the thin cylinder wall below the crankcase deck. Most are reporting it's not a problem but I'm skeptical. Kawasaki made a first overbore set of pistons at 62.5mm and a second overbore at 63.00 mm. I think 64mm is a bit of a stretch unless you go with oversize cylinder sleeves and then there's the head gasket issue, If you go with the 64mm piston set and the head gasket you need to be very careful with the gasket sealant you choose. Hylomar is good and there maybe some better but be careful here since there are reports of head gasket leaks due to the lack of sealant that the overbore head gasket has on it.

The other thought I had was if the engine had rust in the bores or worse, how much damage has the crank journals and bearings received? then what about the transmission shafts and bearings? I've always maintained that if you buy a basket case or a non-runner you need to do a thorough inspection before turning it over. Rust is iron oxide and it will ruin everything because it's more tough than anything in the engine. Once it's cleaned off the rusted items, it floats around with the engine oil until it circulates through the oil filter and gets trapped (if it's bigger than the particle size allowed through the filter) iron oxide is bad shit.

A leak down check is the best way to determine where the oil usage is. You can make your own leak down tester if you have a couple of pressure gauges scaled at 100-150 psi. Basically, a leak down tester is 2 pressure gauges with a .040" orifice in between them. Then an inlet pressure is set for 100 psi and when the supply is forced on the piston when it's a top dead center, the assumption is that if there's less than the equivalent of air supply through the orifice which is .040" then the engine is 100% tight. so the inlet gauge will read 100 psi and if all is good the downstream gauge will also read 100psi. anything less than the 100 psi is read as a leak down percentage, so if the downstream gauge reads say 91 psi then the leak down percentage is 9%. What's really good is now you have the opportunity to find the leak. if you listen at the oil filler cap and you "hear" the leak, then you know you've got leaking rings. if you hear it leaking in through the carbs, you've got a tight intake valve or leaking valve. if you hear the leak at the exhaust pipe, you've got a tight or leaking exhaust valve. If you hear it bubbling at the rad cap, you've got a leaking head gasket.

Now, let's talk about the "valve job". I have yet to see an engine which needed valve guides. if it's burning oil then it's sucking oil past the intake valve guides or bad piston rings. if it's sucking the oil past the guides then the guides have been well lubricated and won't be worn out. The exhaust valve guides are technically under pressure and will never suck in engine oil BUT this engine has a camshaft operating the valves through bucket shims and there's no side load on the valves like there is on an engine which operates the valves through rocker arms, so little wear should be expected on the valve guides. Chances are your engine has never had a valve job, so you should be able to get away with a valve grind and a seat re-facing and a new set of valve seals. If you spent more than $350.00 on a valve job for a 6 cylinder head then you got ripped off. I did the valves on my 1300 myself and it took me just under 2 hours to do all of the work I just mentioned, so if the shop rate is $100.00 per hour...............(do the math)

Bottom line, I'd go ahead and do the work if you love the bike. All in all, if it costs you more than $500.00 to get it back to 100 %, then you really did something wrong.

Kawboy

Kawboy, your estimate is optimistic.

There is easily $500 in incidentals, not counting any major engine components when doing a top end job on a kz1300.

Base gasket will run $80, Head gasket $100, other gaskets $50, water pump seal $50, Oil seal behind the water pump, Cam end plugs, o-rings, valve seals, sealant, etc, etc.... it adds up. So before you have even repaired or replaced any engine components you have spent close to 500.

Now for instance, in my engine the valves had cupped and were not able to be reground... in the trash they went. Intake valves can be found for $15 a piece, exhaust run close to $25 so there's $200 before you even start to do the valve job. Your right though a simple valve job should not cost more than 200 to $300. But if you need valves then its going to double.

Piston rings are available for standard pistons but they run about $45 a set, $270 for the whole engine... not cheap!

If you need pistons the cost go up substantially, I had pistons made at 64mm, no choice either because the only quality rings available were at 62mm (stock) or 64mm, no sizes in between. 64mm is the largest practical bore you can have in the stock cylinder liners, and leaves enough meat in them. I've seen way worse on engines that are pushed much harder. Custom pistons run $800 to $1100 depending on who makes them. The German shop is actually the cheapest quality option.

In my case I think I've got under a couple grand in my 1300 overhaul, but I spent a some extra to have the head ported and flow bench tested and I will run hotter cams as well, but I like to do that stuff to an engine, not necessary by any means. Good head work like that pays big returns, and really perks up an engine.

Now as far as the Chinese/Taiwanese made stuff sold through Japan via E-bay... Yes it is an option but depends an what standards you personally want to hold your engine rebuild to. That's a matter of person choice based on what you want to risk and are willing to spend. $250 for a set of 64mm pistons ring, pins, and a head gasket is very tempting deal.

What is my whole point with all of this? -That cost can vary greatly based on how much work you need to do. Kawboy's estimate is a best case scenario, mine is middle of the road, and a worse case would include a spun bearing on the crank which increases the repair cost astronomically higher. From that perspective I consider the bottom end of 1300's to be a sealed unit. If the bottom end has issues... its toast. Not that it cant be repaired, but the cost becomes prohibitive.

Form the very first engine I did complete rebuild on in High School I was taught to completely tear it apart, evaluate the critical components, and then decide if it is rebuildable, and then order the correct parts. Too many people jump the gun and buy parts before they even really know what they need.

Nice!! Finally someone willing to chirp in. Thanks, I thought I was talking to myself.

You made some valid points. I believe machine shop services for a 12 valve head shouldn't be more than 200-300 bucks. You're right, there's incidentals to be accounted for. I can't remember what I paid for a complete engine gasket set, but a little bird in my brain keeps yelling out $140.00 Canadian.

A set of JE pistons or Wiseco's will set you back probably double the cost of the Chinese ones easily but I guess the point is how far do you want to go to achieve perfection. I think the point here is to rebuild an engine to the point of reliability and not necessarily to get every last possible pony out of the beast.

I also agree with your opinion about a total teardown and access before going forth and just doing a ring job or a valve job or a ........ especially in this case where the engine was run without an assessment after a rather long period of not being run and a change of ownership.
I would also suggest that when you decide to do a cylinder head, it worth while talking to a engine machine shop about the required replacement parts. Valve seals are a common commodity between engines. Intake and exhaust valves are somewhat standard and there's lots of suppliers who can provide for a lot less than NOS parts and probably of a higher quality.

Bottom line, I'm trying to encourage members here to not throw in the towel and cough up for a new engine. It can be a challenge to get an old engine back up and running, but the rewards out weigh the trials and tribulations. Some good old fashioned hound dogging can really pay off.