TOPIC:

Well, a little bad news today. Getting ready to do a top end overhaul on the 77' KZ1000 this coming weekend.
I dragged out my backup rebuilt KZ1000 head for a look over this morning...
has one new exhaust valve, knurled and fitted guides and all fresh stem seals, plus a valve and seat grind.
Or so i was told.
The bad news.... after the "rebuild" by a highly respected hot rod engine machine shop, I had simply left it on shelf in my garage for about 4-5 years as a backup head. No one has touched it but me and there were no cams ever installed. Those are in a different box with caps and bearing shells.
I know, my bad... I'm a dumb ass for never testing the head the day I brought the head home.
Here is the issue:
In what I think is a normal pretest, with no cams installed, I tilted the head up on it's exhaust studs and poured in a couple ounces of acetone into the intake ports, behind the valves.
Yup, runs out of one of the closed intake valves. Drip drip drip drip drip....and one other has a minor seep. Crap.
Flipped it over and did the same test with the four exhaust ports/valves.... one of them, drip drip drip drip, one seeps out slower but visible and wets the area pretty good but one valve actually runs right out of the pocket, in and out of the combustion chamber and on to my workbench... almost like a slightly bent frickin' valve. Oh brother!

Normally I would have used gasoline for this test but I was down in my shop and had a qt of clean acetone left over from stripping down one of my extra set of 26mm carbs.
Not sure if using acetone means anything as it is super thin "wetting" compared to gasoline.

So...what the consensus... a very crappy rip-off valve job?
They didn't even check if there was more then two bad valves the first time?
I let the damn thing sit too long before testing, no warranty!
I took it back to the shop this afternoon to see what they thought... Big laugh here, they say they never would have let it go out the building like this and don't think they even did the work...BULL CRAP!!
Of course they did the work, their shop was right behind mine since 1986!! We share the alley. Out my back door and into their back door. They've done every piece of machine work I've needed since moving there in 1986.

Had a buddy coming over this weekend for the tear down, rebuild and BBQ.... double whammy.
Guess I'm done being the whining ass cry baby.

Pull the valves and see what you got. Why were the guides Knurled? that's only when oversized aren't available.
Steve

swest wrote: Pull the valves and see what you got. Why were the guides Knurled? that's only when oversized aren't available.
Steve

I need to get or make a valve spring compressor for the head.... all have these days is an old auto compressor. I have another KZ1000 head.... I just don't want to spend anymore money on that old beater part... sounds like I will anyhow though, one way or another.
Not sure why I was told the valve guides were internally knurled and reamed to fit... seems like replacements, 4-5 years ago, were easy to find... they are now anyhow.

There's a compressor on eBay for $20. Sounds like you were taken. Internally knurled and reamed? Now they won't talk to you? That's what Yelp is for.
Steve

sucks to hear.
a tear down and inspection is in order.
i would measure the stem to guide clearance,
and try a quick lap to show how far out the valve/seats are.
where are you located?

leon

I'd be more concerned if they hogged out too much material. There was a thread last year where the valves were sunken to the point new seats or scrap heap. I hope not.
Steve

swest wrote: I'd be more concerned if they hogged out too much material. There was a thread last year where the valves were sunken to the point new seats or scrap heap. I hope not.
Steve

that would be why the inspection needs to take place !

leon

Yeah,.. I just ordered one of those $20.00 compressors on eBay.... looks like cheap Chinese stuff but probably OK for a quick tear down.
I did look at all the EX seats, one at a time, with one cam installed and pushing a valve open.... they look as old as the head and possibly lapped... ... I'm convinced now the only thing they did is install one obviously bent exhaust valve, can't even tell if the cut it in, 8 seals and possible lap the valves and seats to clean the crud off them.
Oh well..... at least it is not my original head from my bike and a backup.

Could it be that u are actually using the good head ( prep head)
And the one on the shelve is the old one?
Just saying.....

The eBay compression tool works great.

If the heads were done correctly and new seats cut in the the valve stem ends should be cut also. If they weren't, quit using an automotive shop for your motorcycle. Hope this thing turns around for you.

kaw-a-holic wrote: The eBay compression tool works great.

If the heads were done correctly and new seats cut in the the valve stem ends should be cut also. If they weren't, quit using an automotive shop for your motorcycle. Hope this thing turns around for you.

Very hard to get one by me like this but we were moving our shop and sold our home, moving into a temp town-home in that same time period. I did not pay enough attention and it has bit me in the ass.
I've used these guys off and on for many years and many other motorcycle rebuilds/refurbs, etc.
But looks like I was hosed this time.
No machinist's dye in the seat area either.
The only valve stem tip that looks ground is the one new valve, and it had a #270 shim... all the others have that unmistakable little dot in the center from the bucket spinning around for thousands and thousands of miles.
Live and learn... I guess... .

Are all the shim sizes in the 250-270 range? You might be able to use that head.
Steve