Tearing into my free Kz750 Engine

So due to lack of other available projects at the moment...I decided to start tearing into the Kz750 engine that forum member AuggieDog offered up for free.

This will be my first complete tear-down and build up and I plan on using this engine in my future turbo project. Unfortunately, that is still a distant dream at this point...

Anyways. Here are some picks of what I found. The first piston is somewhat frozen due to the water and possibly the second as well. It looks as though the air injection ports were not plugged when the engine was stored allowing water into the top of the head mixing with the oil. The intake/exhaust ports also weren't plugged, allowing for the issues I'm seeing in cylinders one and two.

On the plus side I am seeing good dark oil drip out of the oil passages on the cylinder block as I seperated it from the cases.

The outside of the engine is in really good shape considering, and should clean up real nice. No broken fins or other cosmetic issues noticed so far.

What's the best process for cleaning up the cylinders once I un-freeze the piston? I am concerned about scoring the inside of the liners as I'm hoping I can go without the 810cc kit for the moment. The pistons and liners measure as original 750cc factory pistons, but I don't have a cylinder bore gauge at the moment.

Anyways...enjoy the ugliness...

I also found a Dyna S pickup plate under the points cover...Merry Christmas to me!

Wow, DD you're gonna be real lucky if you don't have to bore it. That's some heavy duty rust in #1 and #2. I would bet that you have some rust pitting going on. All that iron oxide came from some where. (Your liners)

You could try and hone the cylinders a little, but with the volume of rust present, I would guess that you have some significant pits.

What's the junk around the buckets in the head? Is that more water intrusion effect?

Score on the free Dyna. I just got one of those on my $300 GS750.

testarossa wrote:

You could try and hone the cylinders a little, but with the volume of rust present, I would guess that you have some significant pits.

What's the junk around the buckets in the head? Is that more water intrusion effect?

Yes. The photos are a little misleading, but I have a sinking sensation that you are right about boring...oh well. I was thinking that eventually I would bore it out to the Turbo 810 kit with turbo rods...might just happen sooner (or later) than I expected.

That is water mixed with oil in the bucket area, I believe from the air injection ports as they didn't get plugged. It looks strange because some of the water is frozen...it's cold here.

I think I'm going to start with a soft wire wheel on the liners once I get #1 unstuck. It's been soaking for a couple days now and I'll see if I can free it up tomorrow. Any other suggestions would be awesome. I'll try to get a real photo of the liners once they're clear of the cases.

I suppose I could always try to find a set of good/new liners to replace these if I can't scrape up the cash for the 810 kit/machine work.

"Motorcycles are the best way to turn a large amount of cash into a small amount of cash." Big Sids Vincati.Great book if u havent read it.bj

It's one I've looked at picking up at Borders a couple of times but haven't done so yet. Sounds to me like it's along the lines of "The Gold Plated Porche" which I have read and loved.

I'll pick it up next chance I get - thanks for the suggestion.

Free'd up the #1 piston with a little 1x4/rubber mallet action, but the jugs aren't coming completely free yet. Going to take a breather and tackle it again with a better attitude before I damage something...

DoubleDub wrote:

Free'd up the #1 piston with a little 1x4/rubber mallet action, but the jugs aren't coming completely free yet. Going to take a breather and tackle it again with a better attitude before I damage something...

That's a good idea. Go have a beer, if you're into that. Or find something else to work on in the mean time. Sorta, why I always have parallel projects going. I'll get all pissed off at something, and push it aside for a while until my spirits improve.

When I pulled my jugs, it took a lot of little hits with a rubber mallet before I started hearing the tone change when I hit it. Once it starts sounding different, the gasket is starting to let go. It will come off after a few thousand hits.

A buddy tells me coca cola works good:laugh: never tried it though, he swears by it, pours it in the cylinders and lets her sit.

anytime something starts with " a buddy tells me, says/ or said" be afraid, be very afraid

I hear ya stone, you"re prolly right, but the thing is,what does he have to be afraid of? Coke a Cola?

Coca Cola is acidic but contains syrup as well as fructose, I've heard it good in a pinch to clean car battery terminal if nothing else is available, I dont like the sound of it in a seized piston,ever spill some on the floor ??? then you step on it after it dries??? putting a sticky substance in a stuck piston just dont make sense ( common sense that is),
Soak with PB Blaster and/ or penetrating oil for a few days, tap a little each day, blow some compressed air around the piston, this may help the PB blaster work in better, u still may be able to salvage this if u are patient