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Refitting 1978 F2 barrels

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dazm:
Hi there,

I have a 78 F2 and I'm just about to refit the barrels after fitting new rings, I have a gasket and large O rings for each cylinder and new small O rings but there also appears to be 4 other rubber slightly cone shaped rings on the middle four cylinder studs that I can't seem to find the part code for? Anyone have any info on these? Also any tips for getting the barrels safely over the pistons as I dont have ring compressors?. Any other tips for this stage of the rebuild greatly appreciated :)

Cheers daz

Tomb:
I don't use ring compressors.

Where the chamfer on the bottom of the barrels meets the bore is a sharp corner, I always polish that off to a small smooth radius and polish the chamfer on the bottom of the barrels. That way the rings slip in easily with a bit of fresh oil.

dazm:
Hi Tomb,

Thanks for the tip, makes sense to me, will give it a go. Is it a 1 man job or best with two to lower the barrels over the rings?. Was thinking of placing a block to catch the barrels so they can't drop too far as I get the pistons in place!. Also do I need to use any sealant on the gasket?, I've read differing opinions and don't wan't any excess getting in the oilways.

thanks daz

Tomb:
I can only speak from my own none CB750 experiences.. As you're doing two pistons at a time I find it a doddle, the inside pistons 2 + 3 first with the outer 1 + 4 down out the way, normally the weight of the barrels is plenty to help slide the barrels down as you feed the rings in, once 2 + 3 are in the barrels you can rotate the crank so 1 + 4 come up whilst keeping 2 + 3 in their bores, (maybe a good idea to clamp the crank a little or slide some blocks under the pistons to stop the cank rotating back) now fit 1 + 4 pistons into the bores easing the rings in.

Lads on here will know the CB750s way better than me though.

archmill:
Dazm, is it the ones indicated as "2" in the parts microfiche?

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