Honda-SOHC

SOHC.co.uk Forums => CB500/550 => Topic started by: PennoK3 on November 18, 2020, 12:22:33 PM

Title: Cylinder barrel seating
Post by: PennoK3 on November 18, 2020, 12:22:33 PM

Really simple question guys.

Just refitted the cylinder barrel to my K3, new gaskets and O rings. However its sitting proud of the crankcase by a very small gap (1mm or so).   Do I assume this will close up when I bolt the head down?

Thanks.

Title: Re: Cylinder barrel seating
Post by: philward on November 18, 2020, 03:01:15 PM

Is the large o ring at the base of the barrel seated properly? Just thinking that if its not seating round the bottom of the barrel and you tighten it up it may damage the o ring (and hold the barrel off the crankcase). The experts will be along shortly with more detailed questions

Title: Re: Cylinder barrel seating
Post by: PennoK3 on November 18, 2020, 03:18:18 PM

Yes the O rings are seated but not flush.   I've just put the head on and squeezed up the centre nuts and it looks to be mating fine.

Title: Re: Cylinder barrel seating
Post by: Bryanj on November 18, 2020, 05:42:29 PM

Are you sure the dowels with restrictors at the base gasket are the right way up, the cylinder should go all the way down by hand

Title: Re: Cylinder barrel seating
Post by: PennoK3 on November 18, 2020, 06:07:57 PM

Yes the dowels are the correct orientation.

Title: Re: Cylinder barrel seating
Post by: Johnny4428 on November 18, 2020, 07:24:13 PM

This is probably ridiculous to suggest but did you remove the old o rings from cylinder sleeves before fitting new ones?

Title: Re: Cylinder barrel seating
Post by: Trigger on November 18, 2020, 07:41:45 PM

Jets in upside down ?

Title: Re: Cylinder barrel seating
Post by: PennoK3 on November 18, 2020, 11:29:13 PM

Thanks for the responses.

The restrictors are the right way up and all old seals have been removed.

The new O rings on the bottom of the cylinder liners are a good tight fit but slightly proud of the casting as are the oil seals on the restrictors.

The cylinder block doesn't hit a hard stop but sits about a millimetre or so above the crankcase.   I put the head on and softly tightened (if that makes sense) the first four nuts which closed the gap with no resistance.

Therefore I can only assume its the new O ring seals that are holding the barrel off.

Title: Re: Cylinder barrel seating
Post by: Brian. on November 19, 2020, 08:12:35 AM

Quote from: PennoK3 on November 18, 2020, 11:29:13 PM

......

The cylinder block doesn't hit a hard stop but sits about a millimetre or so above the crankcase.   I put the head on and softly tightened (if that makes sense) the first four nuts which closed the gap with no resistance.

Therefore I can only assume its the new O ring seals that are holding the barrel off.

I did this to my K1 a few months ago, and this sounds exactly right to me, and my bike has run just fine with no oil leaks ever since.

Good luck with the rest of the job!

Brian.

Title: Re: Cylinder barrel seating
Post by: PennoK3 on November 19, 2020, 09:34:22 AM

Thanks Brian 👍