I haven't read all 34 pages of this topic- got here searching for transmission info, but it seems to me you're getting the 5-speed transmission for the wrong reason. Do you really need closer ratios to lower rpm drops between gears? If your 4-speed transmissions are failing from a lack of lubrication, the solution would be to route some oil over to that area, if you don't, you're just going to damage the 5-speed transmission.
I can understand if you just want the 5-speed because it's nicer, but I'd get the lubrication problem fixed before installing it. The 5-speed shafts may be harder, but overheating hardened/heat treated shafts is a bad idea- better to get some oil over there.
Rick
Japan Meets Britain
Good points, and that will definitely be looked at, but I wanted the 5 speed anyways, and the kickstart shaft was peripheral to my decision. As far as what has been failing in the existing transmission, it is the kickstart shaft that is wearing, and eventually starts to move on its own (only in 2nd gear at low speed). This is the second time it's done it, and probably because I've put so many miles on the bike, not to mention the inherent design of that shaft.
I will double-check with my mechanic regarding that question about the oil -- I'm sure he will be able to figure it out if that needs to be addressed, once he actually has the new transmission in his hands. I appreciate the suggestions. Okay, I'm new to this engine, just didn't want to see a nice piece of work damaged. The photo is of a Benelli cylinder head that has a nice and simple oiling system- the oil is pumped up to the head and the tees of copper tubing have holes in the bottom that drip oil right into the hole in the rocker arm support, much nicer than pumping oil into the head and hoping it splashes where it's needed. You could probably find some oil draining back to the sump and divert it over to the problem area without much fuss.
Rick  [/img]Rick
The design of this gearbox means that the kickstart shaft passes through and supports the mainshaft via loose rollers running on the kickstart shaft. As the kickstart shaft wears, friction increases which causes the kickstart to rotate while the bike is being ridden. The 5 speed replacements use a solid layshaft so this problem (and the kickstart :-) ) is eliminated. G
'60 C77 '60 C72 '62 C72 Dream '63 CL72
'61 CB72 '64 CB77 '65 CB160 '66 Matchless 350 '67 CL77 '67 S90 '77 CB400F
Just talked to Bore-Tech this morning, and the 350 kit/barrels are being shipped out today! As well, the transmission will probably ship out this week, so it's all starting to come together.....
I did call House of Balance, and they wondered about the weight difference between the old pistons and the new pistons (I am in the process of finding that out). They said that if it's only a 5 gram difference, then balancing won't really do anything (they said it would need to be more like a 20 gram difference in weight to really change anything). As well, they wanted to know if the crank is pressed together or bolted together (don't forget, I'm no mechanic!). If it's pressed together, they wouldn't be able to work on it. So we'll hopefully get all those answers today and make a decision in that regard....might not end up doing the 'balancing' after all.
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