Motor Rebuild Time

I finally got the courage/need to rebuild my motor. For some time now it has been burning more and more oil (1ml/km)

2 yrs ago I tested the compression (even 100 lbs which is low for a 1000cc)

adjusted all the valve shims no change
fixed all the exhaust leaks I could find

Using a bore scope I took a camera and look down the spark plug holes and found a lot of black blow by the cylinders. As well my head gasket started to leak on 1/4 cyl.

As I started to pull it apart I have found A LOT of oil in the top end of the motor. Im assuming because of the weak rings and pressure in the motor.

Next step is to pull the head off and see what shape its in along with the pistons. What should I look for as I do this?

How can I know if I have to dig into the bottem end? I'm concerned that If I do the top end the bottom will fall out haha.

Also if I have it apart and Im in there what should I replace other then the rings.

Valve stem seals should need replacing and check the valve guides for wear. www.aperaceparts.com can supply new seals and guides.

You didn't say how many miles or what kind of care it had. In city riding, you can need a top end rebuild at 25k miles because the valve seals go and gunk up the valve seats. If the engine has less than 50k, I doubt it needs bottom end work. The rings are probably good for at least 50k with good maintenance.

the 1000 cranks are dam near bulletproof so it shouldn't need any work but i'd take it down the rest of the way and replace the camchain and at least inspect your transmission and clutch basket and replace all the seals in the bottom end.

What do you want out of the engine?

If it's a freshen up on a stock motor:

Replace Cam chain like Tim suggested.

Inspect cam rollers very carefully and replace as needed.

Bore if reuired or re-ring current pistons.

Valve Job and quite possibly guides.

While cases are split have a look at the transmision gear dogs and shift forks.

Those are the basics.


TIPS to make things easier.

1 - READ THE MANUAL
2 - REPEAT Step 1

Get some cardboard and make bolt templates with it. Draw the case pattern on the cardboard and put a dot where the bolts go. Then poke a hole through the cardboard and place the bolts in the template.

Same thing with engine cover bolts.

Egg cartons make great storage for valve buckets.

Keep things organized, clean all your nuts & bolts or replace them as needed.

Larry C

I really hadn't intended to pull the motor out or split the cases. But it can be done.

What kind of money on parts can I expect to put into this? My limit is about $1000. The bike has 36km

Please keep us up to date on your build. Post many photos. I am planning to "Freshen" up my kz900 next winter, and will need all the info I can get. The more often I see this stuff done, the better.

Check out 9am53's post "A newbies Adventure in Maintenencland". I may not have spelled that right. He rebuilt his 1000 this past winter. Lots of pics and lots of help from members.

Good Luck

Galactica wrote:

Please keep us up to date on your build. Post many photos. I am planning to "Freshen" up my kz900 next winter, and will need all the info I can get. The more often I see this stuff done, the better.

Check out 9am53's post "A newbies Adventure in Maintenencland". I may not have spelled that right. He rebuilt his 1000 this past winter. Lots of pics and lots of help from members.

Good Luck

and unfortunately more than $1000 :S

How much more? I can pick up a redone kz for a few K and part mine out.
I have about 3K into it now.
What I want is a reliable classic cruiser. I'm not a big fan on the new big fatman 1000+cc cruisers.

Just to get a rough estimate I quickly went through my main card that my purchases came from. Including paint supplies, sandblasting and sodablasting, exhaust, brakelines, fairing, new master cylinder for the front, new handlebars risers and grips, seat recovering, and some other random stuff I am forgetting that you may not even need it was around $2000...just to do what I did to the motor it could be under $1000 I think. Rings are $80, ball hone was $36 gasket set was I think $50 random shop supplies which I had to buy all of came to a bit as well, but if you have them all you will save that money...Now that I think about it once I get the thread wrapped up I will make a proper full tally of costs so people can know roughly what they are getting into before they start...I had no idea, lol.

So all you did to the motor was new rings?

XL777 wrote:

How much more? I can pick up a redone kz for a few K and part mine out.
I have about 3K into it now.
What I want is a reliable classic cruiser. I'm not a big fan on the new big fatman 1000+cc cruisers.

I think you could do a freshen up of new rings, cylinder hone, valves redone (head overhaul by machine shop), new top gaskets for under $600 (ball park?) if you do the assembly labor.