upgrading my 1976 kz900 to 1000cc

can someone tell whats needed to take my "76" A4 to 1000cc?i have a 1000cc cylinder that says 1012cc and it does need boring and have a machine shop that does only myc's .So my question is whats needed to bolt it into my
900 motor? i would presume the correct thing to do is machine out the cases to except the larger 1000cc sleave bottoms? next question is now that i have to bore it do i have to go too 1080cc any real reason i cannot just get the 1040cc piston kit from Wiseco.my goal is to keep as much reliability as possible, i live and ride up above 7000 feet in the mountains of Colorado and man the air is thin up here! i wanna keep as much meat in my sleaves as possible.

also will my 900 head bolt up without complications?thats a whole lotta questions and i appreciate any info here.its always better to learn from someone else's mistakes...
sincerly Stormin Norman

Stormin Norman wrote:

can someone tell whats needed to take my "76" A4 to 1000cc?i have a 1000cc cylinder that says 1012cc and it does need boring and have a machine shop that does only myc's .So my question is whats needed to bolt it into my
900 motor? i would presume the correct thing to do is machine out the cases to except the larger 1000cc sleave bottoms? next question is now that i have to bore it do i have to go too 1080cc any real reason i cannot just get the 1040cc piston kit from Wiseco.my goal is to keep as much reliability as possible, i live and ride up above 7000 feet in the mountains of Colorado and man the air is thin up here! i wanna keep as much meat in my sleaves as possible.

also will my 900 head bolt up without complications?thats a whole lotta questions and i appreciate any info here.its always better to learn from someone else's mistakes...
sincerly Stormin Norman

The 1000 cylinder will fit the 900 with no problem, no machining required. Pistons, you can use the Wiseco 10.25:1's or you can use 2nd. oversize stock KZ1000 pistons, that will give you a low compression 1045cc motor. A 1045 is a KZ1000 bored 1mm oversize.

My 76 was sleeved to 1105 33 years ago by Superbike Mike in Ft Lauderdale Fl and is still going strong & stout. I live at 3700 ft in Billings Mt but most rides are over to Cooke City Mt & thru yellowstone Park over the Beartooth Pass which is around 11,000 ft at the top. You need all the snot you can get at that altitude, even a big motor seems lame. It has the 10.25 pistons in it with a 395 lift, 260 duration cam and ported head

mtkawboy wrote:

...over the Beartooth Pass....

One of my all time favorite rides!!

At least in July and August.

Stormin Norman wrote:

can someone tell whats needed to take my "76" A4 to 1000cc?i have a 1000cc cylinder that says 1012cc and it does need boring and have a machine shop that does only myc's .So my question is whats needed to bolt it into my
900 motor? i would presume the correct thing to do is machine out the cases to except the larger 1000cc sleave bottoms? next question is now that i have to bore it do i have to go too 1080cc any real reason i cannot just get the 1040cc piston kit from Wiseco.my goal is to keep as much reliability as possible, i live and ride up above 7000 feet in the mountains of Colorado and man the air is thin up here! i wanna keep as much meat in my sleaves as possible.

also will my 900 head bolt up without complications?thats a whole lotta questions and i appreciate any info here.its always better to learn from someone else's mistakes...
sincerly Stormin Norman

A) Your Cylinder actually states 1.015L or 1015cc as in the first photo.

If you use the 903cc Block that is already on the bike, you ONLY need to Bore the Cylinder for the 1015cc Piston Kit, and it will conceal the fact that the bike is Bigger than 903cc's, as in photo two.

C) For practical purposes it would make more sense to purchase the 1075cc kit as opposed to the 1045cc kit, as they COST the same, so take advantage of the slightly Bigger Bore. The 1075cc kit allows Sufficient Sleeve Wall thickness without compromising reliability.

D) Going to the 1015 Cylinder, requires boring the 900 cases to accept the Larger Sleeves, if they are 900 style cases. Which means disassembling the cases to have them Machined. 900 cases start out "Z1E" on the Number pad which is next to the Oil Filler Cap. The 1000 Cases start out "KZT" and these type cases will accept up to 1105cc Piston Kits, before they have to be bored out to accept anything Larger in CC's.

E) I mention all of this because although you state the bike is a '76 900, and unless you've purchased it "New" you will not know what is happening inside until you "Open it up" and look. People may have been inside to change/fix/repair/upgrade, prior to you owning this bike.

F) Yes, the 900 head will bolt up without issue.

G) If you choose to go with the 1015 Cylinder and have the cases, and cylinder bored out, you might consider going to the 1105cc Piston Kit. It will cost the same as the other two kits, but will allow the biggest bore possible inside the 1015 Block without having to re-sleeve. Some people here may disagree, and say that the wall thickness is not enough for their liking after boring the cylinder for an 1105cc kit, or that it's prone to overheating, but it's bullet proof when everything is in tune.

Photo 2

Ive been snowed on up there in July and August. I cringe when I see people heading over the pass in a t-shirt. Ive seen 107 at the bottom and 37 at the top in the time it took to ride there. It can change unbelievably fast too, if you get rained on up there without the right gear you are in big trouble. People think Im nuts when I take a big bag of gear with me, but Ive been riding it for 30 years. My 76 900cc engine was sleeved, not bored to 1105. Down south Superbike Mike was the man on the old KZs

mtkawboy wrote:
My 76 900cc engine was sleeved, not bored to 1105. Down south Superbike Mike was the man on the old KZs[/quote]

I'd have to say Elmer Trett was the man down south.

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