Nelson's KZ1000 Fighter? build

I think I read on Larry's site that welding the crank is only needed for drag racing with a slick. So I'm not planning to do that even with a 1075 kit.

Nelson wrote: I think I read on Larry's site that welding the crank is only needed for drag racing with a slick. So I'm not planning to do that even with a 1075 kit.

it was common for the cranks to twist without a slick and track. you should be fine though,without the bigger cc's.
your call.

Score! I found the 1075 kit. $305 from fleabay complete with matching cylinder block. I just finished checking all the clearances (piston to cyl, ring end gap, etc.) and it's all like new specs! The rings are even new spec! Such a deal. There's some minor fin damage, but I can clean it up enough that it won't be noticeable at all after it's painted.

If you don't know - The stock pistons are 8.7:1 compression (I think) and these are 10.25:1 plus 60cc. I'm expecting a nice power boost and a motor that's still very practical and reliable.

Anyone know if I can use OEM wrist pin bearings with these?

My only concern: The aluminum gasket surface on top is pretty pitted in some places. My old one is machined smooth. Is this likely to be an issue? Perhaps I should get a bit milled off?

Just measure the oem pins length. they should be fine.
the block surface may seal ok but the best bet would be to have it milled. if u check your deck height u can have the deck milled to reduce the deck height. this will give u a tighter squish clearance and it will then be less prone to detonation. i would set the squish clearance at .040".

Yesterday I started to scrape the old base gasket, then remembered I want it on there for checking deck height and piston/valve clearance. Most of it is still intact.

try to measure the thickness of the old gasket as well.

Nelson, you dog! That's a nice score on a 1075 kit. JMHO that pitting looks like factory casting marks to me. I bet that you would be just fine to run it like that, but a simple deck job could clear all of that up. I bet you wouldn't have to take 0.010" to get past 95% of the pits that you see there.

yes I am truly the king of getting something for nothing!

I think my old cyls may have been milled by someone else which is why the casting looks odd to me by comparison.

speaking of which... I just got some adjustable cam sprockets for $10, shipping included.

Checking valve guides today. I don't have a small enough bore guage so I thought I'd try the wobble test. see pic. The intakes have virtually NO wobble. the exhausts have .004" to .005" using the test shown below. Seems pretty good to me, what do you guys think?

if you can feel the valve physically moving in the guide id say its time for guides