1968 Honda CL450 Cylinder Problems

| 7/13/2016 12:00:00 AM

Motorcycle Classics tech expert Keith Fellenstein

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Cylinder problems

Q: I recently purchased a 1968 Honda CL450 with just 782 miles on it. The cylinders are out of round, apparently. I had the lower end inspected and the shop told me it was nice and tight, and the pistons are fine, also. My question is, should I bore it, which will then require a new set of piston kits, or should I sleeve it, in which case I could then leave the top end alone except for new rings? Tim/via email

A: Either of those options would work, but I think boring the cylinders and fitting oversize pistons may be easier to do and probably less expensive than resleeving. Plus you get the added benefit of a little more oomph from more CCs. What makes you think the cylinders are out of round? Is it smoking excessively? You could try the test I suggest in the first letter to confirm the diagnosis. MC

8/11/2016 8:59:37 PM

A bit of an add-on to what Keith said, the 450s had cam and follower issues so before commencing the lower end, inspect the cam followers and cam for de-lamination (chrome peel) and scuffed surfaces, everything should be shiny and smooth, use Mobil 1 when done. Good luck

7/28/2016 11:00:55 AM

The oil pump on the 450 is a small piston pump and it takes a while for oil and oil pressure to get up to the cam bearings , If I remember right at Honda school in NJ it takes a full minute and a half ti get oil up to the cams bearings . so let it warm up easy.