KZombie

You must use the correct manual for your bike; it needs to include your bike's year and model for things to match. Forget using anything from a KZ550 manual; that is an entirely different engine. Also, the page from the newer KZ650 manual you show has a different setup than your 1979 bike. Notice the chain in that diagram is a hyvo chain. That is totally different than the early KZ650 roller cam chains. Ed

Well damn. I just checked and the fsm i ordered is for 1978 650 c1 & c2. KZombie as i have learned is a '79 650 c3 but the only differences i could find between c models were things like 3 disc brakes, tank capacity, wheels, etc.

Hmmm? Good thing i'm patient & not in a rush to finish it huh?

I can always press onward with everything else it needs which is everything until the fsm arrives to see if it is going to help. Thankfully, i don't need a manual for body & paint stuff!

So does anyone actually know what the valve gaps should be on this bike?

The correct fact manual for the 79 C-3 is KZ650C-022801.... Cast wheels, front dual discs and rear disc brake..... Pin count like I said should be (but wait for your manual to be sure) 36 starting with the arrow on the exhaust being flush with the cyl head and facing forward ......the first pin pointing to the arrow is 0..... then you count 1-36 and the 36th pin should be at the intake cam arrow flush with the rear of the head. This of course is at the T mark on 1/4 under the points cover. When you are done be sure to clean and put blue locktite on the 4 allen heads of the upper cam chain sprocket and tighten to 6-8lbs or around 80-84 inch lbs.... think about replacing the 4 rubber dampers (I did) although this will be in the manual.

Valve clearance should be .003 to .007........ Most shoot for the middle range but I set mine closer to .007 so you don't have to do it as often but they are a little noisier that way.

Well sorry to hear about the troubles, but I do have to say I really like reading what you put down here it is not just engaging and helpful for others going through a similar process but it is entertaining and makes me want to keep seeing what is about to happen! Thanks for sharing, keep up the great write ups and best of luck on the engine, hope to Goodness that you don't have to dick with bent valves, but if you do you are definitely in the right place to learn from an amazing and incredibly knowledgable group of people!

Thanks for sharing and keep writing and making us laugh (or at least me :laugh: )

Brett

So i was surfin' the sofa last night when your response came in to my phone. I tried to remain engaged in the tv show my better half had blipped on but the KZombie was calling from 10' away and i finally had to get up and check the pin count. Serendipitously the count was right on 36! Score one for me! Even a broken clock is correct twice a day

So now it's just those gnarly exhaust valve gaps to resolve. Fingers crossed but it is what it is and if a tear down is needed, well, i'm up for it. Still going to try compression testing later today with any luck.

Another banner day in the garage!
I really should have been out riding the 550 in this awesome weather but couldn't resist to check-in on KZombie a little further...

I pulled the starter motor off the engine and tested it on the garage floor with the 550's battery and Varooooom!
it works great!
Slung oil all over the damn place but hey it's my garage so the wife don't get PO'd about my mess (so long as I clean it up :whistle: ).

Cleaned and installed the starter motor back into the KZombie and using the 550's battery again, clamped onto it, negative to engine case and positive lead dangling off the starter over the positive jumper cable, at the ready. Grabbed my compression gauge, stuffed it into cylinder 1 spark plug hole and used my foot to tap the starter lead on the positive jumper cable.
RmmmRmmmRmmmRmmm!
Sweet!
Engine's spinning good!
Shiplits!
No compression reading...
I tried every cylinder and basically got the same thing - no compression readings.
Hmmm?
Looks like Steve was right.
Something is afoot with the intake valves and hence my way outta whack valve gap readings...
OR IS IT?
Then I remembered I had my trusty and dusty borescope!
Cool!
Finally a job with this thing that might be fun and prove beyond shadow of a doubt that this old KZombie isn't given up the ghost yet.
Quick!
To the Bat Cave and grab the Bat-scope from the Bat-shelf! :laugh:

So here it is (assuming I figure-out how to link a video to this). The results of the borescope inspection. Keep in mind that the engine is set to TDC 1/4, so in this video, the only valves opened via a camshaft lobe is intake #2 and exhaust #3 (they're obvious when you see them).
I have to apologise for the jumpy, low-grade video. It's my old Bat-top that lagged, not the Bat-scope.
Without further ado:



[ OR click this link to Youtube KZombie650 ]

So that happened. :blush:
Sorry if y'all have nightmares about Proctologists or whatever. The truth hurts. Ouch! :pinch:

Guess this leaves no doubt about it. KZombie needs an engine tear down.

almost took the heads off a couple them ex valves :ohmy: !

leon

So after the distressing discovery with the scope, I've been pondering what to do with KZombie650...
I'm still not entirely convinced the valves aren't just seized in position versus being bent.
Clearly, an engine rebuild is needed here, torn down to the bare case.
I've been up to my elbows deep in engine rebuilds lots of times before but not a KZ.
One of the things I'm kinda' learning here on the forum is, parts aren't readily available for these puppies. I'm used to opening the parts catalogue and seeing my credit card begin to smoke from friction but it appears this may not be an option here based upon another member who just had a valve drop and the general consensus is - swap-out the whole engine.
My concern here is that this bike did in fact sit in an open field for likely decades. The bike says built in 8/78 and the last tag sticker is 1982 (hence the lower mileage) but this gives me the impression that there is a more than likely chance the entire engine internals are going to look like that video of the valves. Seems logical to assume this anyway.
What would you do?
Assuming I can find a good engine machinist here in Waco AND hopefully find an unknown as yet parts list; should I even try that route?

You might just need a few valves, seals and gaskets. It's worth a look. Take the head off, then decide.
Steve

A wonderful Friday is upon us. Sunny and warm. The Handbuilt Show this weekend that my son and I are going to on Sunday for inspiration and maybe a wee little bit of the beer to be found in the vacinity

I finally got the head pulled off the KZombie650. I was expecting the worse - bent valves, knackered piston crowns etc. Instead, this greeting my depressed face:


Hmmm? No F'd-up pistons? No apparent scarring of the cylinder walls (aside from dirty oily residue).

So I anxiously put the cam caps back on and flipped the head over to see the real damage:


Ah hah! I knew it!.. Wait? What? Where's the bent valves? Where's the damage? I mean I stared as close as my vision would allow me and couldn't see valve gaps like what I was seeing through the scope. So I got the idea to flash a torch up at the head/valves and peek down the intake and exhaust ports:


Well that can't be right... If I can see light through a valve seated, then certainly, combustion is going to be an issue. But what is actually happening here then? I mean, this IS a lower mileage engine. Is this the result of the PO not doing his valve adjustments? Is THIS what burnt valves/seats look like? I dunno but I'm going to find out here in a few minutes when I take the head to a machine shop and have them give it a bath and inspection.
I'm really quite PO'd because when I was up at the shop last weekend to get the bike, I didn't think to grab the cylinder head valve spring compression tool. Doh! :blush: I could just pop these bad boys out myself and get a closer peek but Nooooo. I'm a lame-brain and left the single tool required to take this inspection to the next step. Gawd I hate being an idiot sometimes. Most times it's advantageous because other people expect less of you but when you're relying upon yourself and only you to blame... Life is like a box of chocolates; right? :silly:

So, trip to the machine shop is eminent (waiting on "Gary the motorcycle guy" to be in the shop) but I got to wondering something about 650 heads. This is a question for the real machine-head gurus here:
Can I swap this head for an earlier head that didn't use the new fangled emissions reed valves? I'm ASSuming the head would fit the cylinder block and simply be less the reed valve porting. I just figured if I have to swap the head (unknown yet if I can save this one) then maybe I could go to an earlier head and have that cleaner valve cover.. I know it's starting to sound like form before function but really, the later valve cover on my 550 is just blocked-off anyway.
Likewise, assuming the '79 head can be saved and rebuilt, could I have the machine shop TIG-up those ports that feed the reed valve assemblies and deck the topside of the head so an earlier valve cover would seal?

If you get another head, you'll have to go through it anyway. I doubt they are burned. Keep the pics coming.
Steve

Hey Steve.
Thanks for the vote of confidence. Sometimes it's all I need to hear especially when it's from the guys here like you that have gazed down this kinda' rabbit hole before and have an inkling of what's at the other side.
I had to make a return trip the machine shop here in Waco after dropping the head off. The young guy that took my cylinder head earlier had asked for "the tech specs" on it.
I put on a brave face and assured him "Oh.. yah. Of course! No problem. I'll return with those later and bring my shim kit too (which he requested if I had one)".
Immediately, I got back in the car and panicked. I was thinking the machine shop needed the manufacturer's machine specification for like valve angle, bore sizes etc.. You know, the shit seen on blue printed engines and such. Ultimately, I returned later with bascially nothing but the shim chart and a few photocopy pages of the owner's manual and a 650 pdf file.
Luckily, upon my return, I met with the shop owner who kinda' looked like a summertime Santa - visualize Santa in like a Hawaiian shirt. He was "Gary the motorcycle guy" the receptionist told me about earlier in the day on the phone. Whew! Totally cool man. I handed him my shim kit, which he recognized immediately (whew!) and then a bunch of loose leaf paper copies of all the "technical specs" I could dig-up. Gary flipped to the first page copied from the owner's manual that showed the valve gap settings and said "Oh. Ok. This is all I need...".
So in the end, my panic and haste for "technical specs" was unwarranted. Whew!
Gary had apparently already looked at my cylinder head and when I asked him what could cause those gaps between the valves and seats? He said "isn't this the bike that sat in a field for some years or decades?". Um.. yup.. this is the one.. He seemed to think it was probably going to be okay and just needing some good cleaning and light machine work to get everything cooperating again. Whew!
In any case, I told him I wanted them to replace the valve stem seals and any valves or seats they deemed needed. That's when he told me "Well, I'll machine the head no problems but I don't supply parts (for a 30+ year old metric bike) nor will I build the engine for you. I'll call you once the head is dismantled and tell you what parts if any need to be ordered or replaced. You can bring them in and I'll install them of you can reassemble the head yourself later with the replacement parts."

So Gary was totally making my day a whole lot better. Anxiety meter went waaaaay down and suddenly I didn't feel like I had just dropped my new born baby off at the teenage babysitter's for the first time in my life. :laugh:

If this cylinder head works out, I guess I can live with those kinda' ugly reed valve breather caps if all I needa' do is replace the valve stem seals and some valves or whatever.

Speaking of which; someone here (and I was thinking it was you Steve?) mentioned there were like good/better/best valve seals? What do you recommend I get? Seems like it was some brand name or maybe it was a type of seal. I forget now... My CRSS seems to be acting up again.