1981 Kawasaki KZ750 Resurrection

[Nessism]

Doesn't look like much but some progress.

Two coats of VHT engine paint primer followed by three satin black coats. Rattle can paint sure makes things easy compared to a spray gun. Scrubbed out the inside of the cases before painting of course to make sure all the grit was out. Generally speaking I don't recommend media blasting engine parts like I did because the grit goes into all the oil passages. The blind passages were plugged before blasting of course, and then liberal amounts of cleaner was forced through all passages regardless. Broke out the long engine brush kit and ran out every passage I could find. Should be okay. Going to bake everything tomorrow night. After curing I'll take some sandpaper to the DOHC highlights on the valve cover and skim off the paint. Good fun!

P1020001 by nessism, on Flickr

P1020002 by nessism, on Flickr

P1020003 by nessism, on Flickr

P1020004 by nessism, on Flickr

P1020005 by nessism, on Flickr

[Nessism]

Oh, and the Kawasaki engine case casting quality sucks compared to Suzuki. The surface finish was abominable; rough, slag everywhere, casting sprue removed with a hatchet (or similar), just plain sucky. I smoothed out some of the rough marks but lost patience and said F it. Good enough.

[SVSooke]

LOL you should see all the spatter,slag and other stuff on a 83 GS750+ frame,the 78 1000 and GPz frames aren't perfect but are MUCH cleaner.

[rustybronco]

Ed, I know what you mean. The castings on my GS1000 were so crisply made. What impressed me the most was how clear the bolt tightening sequence numbers were.

[Nessism]

Baked out the paint last night. Didn't stink as much as I was expecting. The instructions said 200F for one hour, which was done, except the temp was cranked up to 230 for the last 15 mins.

Blasting and painting the head and cylinder are next...

[Nessism]

Blasted and painted both cylinders: original and cylinder from the spare engine. Need to decide pretty quick if I'm going to just re-ring, or put that big bore kit into play.

Had a little over spray inside the valve cover after painting, but brake cleaner on a rag takes it off pretty easily. Mind you, this is after baking the VHT paint per the directions. Not a fan of rattle can paint for this reason. Wish I knew what kind of paint was used originally. Kawasaki painted the engine inside and out before machining, and whatever they use it sticks well, doesn't flake, and is impervious to oils/chemicals for the most part. A far cry from this VHT rattle can crap.

P1020011 by nessism, on Flickr

[chuck hahn]

Been following along Ed....looks awesome.

[Nessism]

Been following along Ed....looks awesome.

Thanks Chuck!

When baking the cylinders at 200F a few of the liners raised up. Pushed them back down easily using a press at work; they are quite a loose press fit. Read on someone's KZ650 hot rod build thread that when boring liners such as these the machinist mustn't take fast cuts or the liner will spin in the casting. I believe it.

[chuck hahn]

I put the jugs on a cookie sheet head side on the sheet. This keeps them setting all the way down when the case expands and loosens them up. Leave them as is and let them cool on the sheet and they dont move. Learned that lesson when I suddenly heard what I thought was the oven rack collapsing when I baked the 73 TX 750 jugs. Sat the jugs on the bottom of the liners and then they just popped up the top about 4 inches. Thought WTF!!!!!!

Grabbed the hot mits and sat the jugs on some 4X4s and then pushed the liners back down. Lessons learned.

[Nessism]

P1020013 by nessism, on Flickr

[rustybronco]

This is going to be one awesome looking machine when it's finished. Love the way the valve cover came out.

[Nessism]

Thanks for the positive feedback Dale.

The valve cover highlights the quandary I'm facing: to polish or not to polish (the aluminum bits).

This bike had/has a lot of corrosion damage. Engine covers for example are pitted pretty deeply. Kawasaki didn't clear coat the engine covers and various aluminum parts the way Suzuki did. I bead blasted the valve cover end caps (so to speak) but would prefer a polished look. Polishing everything is going to be a LOT of work though. Not sure I'm up to it.

[rustybronco]

How much work would be involved to sand bead blasted engine covers with 800 grit and clear coat them? You could also throw money at the problem and buy ones that aren't pitted so heavily.

[nvr2old]

Everything you've done looks top-shelf, for sure. I've found that anything aluminum can be brought back with enough sanding..even if you have to start with a file. It's just how much time and effort one wants to spend on it. 80 grit will take just about any pitting problems away, followed by 180, 400, 600, 800, 1,000, followed by aluminum polish. It's a pain, but the results can be had by persistence..which you have proven to have time and again with the projects you've shown us.

[srsupertrap]

Doesn't look like much but some progress.

Two coats of VHT engine paint primer followed by three satin black coats. Rattle can paint sure makes things easy compared to a spray gun. Scrubbed out the inside of the cases before painting of course to make sure all the grit was out. Generally speaking I don't recommend media blasting engine parts like I did because the grit goes into all the oil passages. The blind passages were plugged before blasting of course, and then liberal amounts of cleaner was forced through all passages regardless. Broke out the long engine brush kit and ran out every passage I could find. Should be okay. Going to bake everything tomorrow night. After curing I'll take some sandpaper to the DOHC highlights on the valve cover and skim off the paint. Good fun!

Ed,

Your engine case turned out great. Its going to be awesome whether you polish the aluminum pieces. I am betting you will

No comment on engine casting quality because these bikes (Suzukis or Kawis) were never intended to last thirty or forty years but I would add be carefully when you retighten those front engine mount bolts. The nuts on the inboard side are kinda of a loose fit and when you start tightening the corner of the nut rotates against the casting before it stops . . . so all the force is concentrated along a single line instead of the flat of the nut. Luckily the torque is pretty low