Kawi2strokes.com Forum

I bought a motor and was told it had some port work. I'm beginning to wonder what else was done. I measured all three cylinder bores and they're all about 72.3. I was planning on honing them so it looks like it will be to the next oversize.

I tried to measure some of the port dimensions and it looks like they did have some work done to them. Nothing radical.

But I think they may have done more than that but I'm not sure how to tell. Is there any way to measure the cylinder height to see if they machined the head mating surface? Below is a picture of the top of the center and the right cylinder. The center cylinder has a raised landing for the head gasket and head. The right cylinder looks like it's been machined so the gasket surface is pretty much flush with the top of the fins. The left cylinder looks a lot like the right cylinder. Is this normal?



So, how do I tell if the left and right cylinders have been machined?

I guess the most important thing is that if they took a few thousands off the right and left cylinders it would raise the compression ration compared to the center cylinder. Don't like that.

The motor was shipped to me in pieces so I have no way of knowing if all these parts were actually from the same motor. Doesn't really matter but I do want to make sure it all matches up when I build it back up.

Any input is welcome,

Dave

You need to get the stock dimensions from the resource site and compare yours to them.

By putting a cylinder on and bolting it down gently without a head, you can measure the deck height. Then by CCing the head you can tell what the compression will be. It's just a matter of measuring everything. If you have a cylinder bolted down, you can use a degree wheel to check port opening and closing dimensions, or you can measure the port roof and floor distances from the deck.

72.3 isn't likely to be the correct bore diameter since pistons are available in 1/2 mm increments, so a more accurate measurement is needed.

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If it surges, that's normal, upshift.

Another way to compare heads is to measure squish.
That also would require putting cyls over pistons and bolting down heads.

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Answers are here: http://kawatriple.com/

Measure the exhaust port height. Top of the exhaust port to to top of the cylinder. Compare to stock.

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Current bikes: H1 69,71,72,76 KH 500, H2 72(2),73,74,75(3) , 77RD 400, 08 KLR 650. 76 KZ 900, Yamaha RZ 500, ihave so many triples gave up listing them.
Have seversl tons of H1/H2/S parts for sale, http://www.triplestuff.net dhg1337@gmail.com

Reposting a reply I thought I'd already sent but isn't showing up for me.

I measured the bore with a new micrometer, didn't think it needed calibrating but it did. New readings were all about 2.855" (just over 72.5mm) which makes more sense. Also goes along with my feeling that this motor has had a fair amount of work.

To check the cylinder height I put the cylinders upside down on my table saw top (cast iron, very flat) and ran a straight edge across the case mating surface. No visible gap under the straight edge. Seems like the cylinder heights are even.

I did try to measure the distance from the exhaust port to the top of cylinder, since this number is given in the Kawi manual, but it's had to get. There is no sharp edge on the exhaust port, probably from port work. It's just guesswork trying to measure.

Still looking for a machine shop in the area that's familiar with Kawasaki's.

Thanks,

Dave

You need to estimate it as closely as you can. There shouldn't be sharp edges on ports because they will snag rings. Just measure them all the same way and see how it compares to the stock numbers.

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If it surges, that's normal, upshift.