KZ1000 head rebuild

This winter I am thinking about rebuilding the head on my 77 KZ1000. I am getting a puff of blue smoke when I let off the throttle to shift, which I think means the valve seals are leaking. How difficult is it to change the seals? Do I need a special tool to do this? I don't want to spend a whole lot of money so I'd like to do this myself if I can.

Almost forgot, the bike has 35,000 miles and the previous owner installed new rings last year.

Thanks

fordtruck wrote:

This winter I am thinking about rebuilding the head on my 77 KZ1000. I am getting a puff of blue smoke when I let off the throttle to shift, which I think means the valve seals are leaking. How difficult is it to change the seals? Do I need a special tool to do this? I don't want to spend a whole lot of money so I'd like to do this myself if I can.

Almost forgot, the bike has 35,000 miles and the previous owner installed new rings last year.

Thanks

The special tool you will need is the valve spring compressor so you can get at the seals. I think the seals are not that hard to replace.

I am getting a puff of blue smoke when I let off the throttle to shift, which I think means the valve seals are leaking.

That wouldn't have been my guess. I recommend a compression check (cold to hot) to get a gauge on cylinder wall wear.

The valve seals may very well be bad, but check the compression too.

Replacing valve seals it not a very big deal. However, you will need a valve compressor tool. You can either buy one for about $150 , or make one for about $10 using an 8" C-clamp and a short piece of steel pipe. Check the filebase here where you'll find an article on how to do this.

The only other special tool you'll need is a small hook pick to pull the seals out. You'll need to remove the valve cover, cams, shims & buckets, then use the valve compressor to remove the valve keepers and springs. You can then use the pick to pull the seals out and replace them.

if you are going that far in its time to check the guides and do a valvejob as long as its apart

PLUMMEN wrote:

if you are going that far in its time to check the guides and do a valvejob as long as its apart

Your best bet, the safe one, is to do a compression check and a leak down test. Then, armed with that information decide if the block should also come back off again.

Absolutely correct. With 35K on it, it's valve job time.

If it's smoking on decelerration, it sounds to me like the rings didn't seat properly. There's no way to know how the bike was broken in or the procedures used when the rings were installed. Who knows, the block may have not been washed properly or possibly even not deglazed properly. The bore could also be near max tollerance.


Do it right or do it over......

Larry C

Z1 has the tool and seals very reasonable. You should not have a problem with the guides unless the bike has been abused. I did my heads at 40000 miles and the guides were ok. As long as you have the valves out, check the them and the seats for wear. I was able to clean mine up with lapping compound.....chris3

Thanks for all the great info guys! This winter I will probably tear into it and see what needs replaced. It runs good, although I have to run a hotter sparkplug in the number four cylinder to keep it from oil fouling. I'll keep riding it until the weather turns cold, then tear it apart.

Since you posted this question where "what tools, don't want to spend a lot of money etc...) why not just get a basic valve job on the head for ~ $200-$300...

Example, proper tools will run you ~ $100-$200 pending e-bay or brand new. Valve guides and seal ~ $80 total.

For approximately the same money, you can have someone who knows what their doing accomplish a basic valve job. Especially if the valves require some grinding. You supply the guides and seals and your done with it.

I'm all for doing everything I can myself but some things I want done correctly cause if I'd screw this up, which I tend to do at times, I'm screwed.

Just my thoughts,

OMR

It is only $189 for a Serdi valve job. This not only reseals the head, but provides increased flow past the seats.

However, contrary to the post above, we see very few high milage KZs that don't need guides, so that is another $165.00
Seals add $18.95

HEADS

Jay

Ape Jay... $165 for guides? I'm assuming you meant $65.

Z1 has the exhaust guides (4 each) @ 45.64.
intake guides (4 each) @ 40.72. Add tax and crap around $80-$90. Set of 8 seals @ 12.24 plus tax.

Now for my project, APE heavy duty valve springs @ z1 $61.36.

Now the real killer is the damn CAM bearings @ $111.84, ouch! But it must be done...

Anyway you look at it. For a bare minimum or a basic 3 grind valve job, your speaking anywhere between $300-$500 for parts and labor. With a 3 way grind & port and polish... well the price goes up.

Again, for how crucial the head is in a fine tuned machine, let the professionals handle this part no doubt about it. For those that have the tools and know how, I'm envious.

OMR

APE Jay wrote:

However, contrary to the post above, we see very few high milage KZs that don't need guides, so that is another $165.00

Jay

Mine had 75k miles when I tore it down, so I assumed it needed new guides and I bought them from kawi (very pricey)before I put the head in the shop. Not a single of the original guides showed any measurable wear. I didn't believe it so the guy ran the gauge down them as I watched. The new guides were actually a half thousandth LOOSER than the old ones. The machinist said guides normally don't wear unless the valve is set up wrong so that there is a rotating force twisting against the sides of the guide.

So, I have four brand new guides for sale for a 750 twin if anybody wants them.

Old Man Rock wrote:

Ape Jay... $165 for guides? I'm assuming you meant $65.

Z1 has the exhaust guides (4 each) @ 45.64.
intake guides (4 each) @ 40.72. Add tax and crap around $80-$90. Set of 8 seals @ 12.24 plus tax.

Now for my project, APE heavy duty valve springs @ z1 $61.36.

Now the real killer is the damn CAM bearings @ $111.84, ouch! But it must be done...

Anyway you look at it. For a bare minimum or a basic 3 grind valve job, your speaking anywhere between $300-$500 for parts and labor. With a 3 way grind & port and polish... well the price goes up.

Again, for how crucial the head is in a fine tuned machine, let the professionals handle this part no doubt about it. For those that have the tools and know how, I'm envious.

OMR

I posted a link to our head work page. Guides are about $67.00. Changing them out and honing to size $95.00. So if the head is in the shop and needs guides, it is about $165.00

If the valves are all good, and most are, if the head needs guides, the whole thing is about $375.00, and that is with more flow past the seat.

Jay