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Discussion Starter · #1 ·
I bought the NE Engine Gasket set for my CB350G rebuild. The package is labelled CB350K-K4 but I assumed it is common to the various 350 bikes. Most of the bits in the kit are obvious but there’s no list of contents. Hence, a couple of questions arise. . .

The set includes 4 valve stem seals. I know they are fitted on the CB360 but there’s nothing I can see on the 350 microfiche and they were not previously fitted when I pulled the motor apart. Is there a reason for this or should I fit them anyway?

There are also 2 small rubber sleeves of a similar diameter to the valve stem seals. Each end of both has a slight internal chamfer. Does anyone know what are they for?

Thanks
IMG_20190328_162854(1).jpg
 

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doode is right about the valve seals. The other two I think go around the knock pins on the carb side between the cylinder and head.

Bill
 

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Discussion Starter · #4 ·
Thanks guys, I think my earlier reply got lost somehow.

Another problem with this gasket set are the 2 cylinder to crancase O rings. They are too thick to push into the recess correctly and that stops the barrel sitting flush on the base gasket. I checked with David Silver Spares and the Honda O rings are thinner so that's the way to go for me.
IMG_20190328_170101(1).jpg
 

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Just saw the same thread for a 400t. The O- rings in the kit are to large in dia . I think there 2.55 mm without looking . You need 2 mm dia. look on CMS and get the part number then check and see if Partzilla has them in stock. If you have the part # just go to Partzilla. The ones for the 400 were $4.95 ea.

Bill
 

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Discussion Starter · #6 ·
Thanks Bill,
Yes, same for me. I measured the gasket kit O rings to be 2.5mm and the Honda spec is indeed 2.00mm. I’ve got the Honda part no. so will order those.
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It’s sods law how one bad thing leads to another. If those O rings had been the correct size I wouldn’t have been forced to pull the barrel off and in the process stupidly not taking enough care to ensure the cam chain tensioner was vertical and free. Getting it snagged popped the camchain roller pin up with the base gasket and one of the retaining rubber holders has dropped into the crankcase! I’ve removed the pistons in the hope that I can turn the engine upside down and maybe it will drop out. Other than that it might not be too damaging to leave it . . .
 

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Those roller pin rubbers are a pain in the but. I would do all I could to remove it. If you left it in it may after some time break up and maybe plug up an oil line. If I couldnt get it out I would split the cases again . Yes a lot of work but I would never feel comfortable knowing it was in there. I just noticed your in the UK so bill Silvers spares would be the way to go.

Good luck

Bill
 

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I'm at the same stage of assembly with my SL350 motor, and it looks like the orings in my set are too thick to allow the cylinders to seat properly on the case. In the above photo, is the whole top end assembled and torqued to spec and there's still that much gap? If so, it looks like I'll be looking for the skinnier orings too.
 
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