New R5 Owner

[Coop07]

Hello everyone.  I just purchased a 1972 R5 and it is in the process of being shipped to me and I hope to have it at my door just in time for Xmas, hopefully the picture attachment works!

This will be my first 2 stroke that I have worked on or ridden, but I have built a couple of older Honda 4 strokes in the past.  For reference, my other motorcycle is a 2007 Aprilia Tuono and I have done some amateur racing events and lapping days.

The bike needs a full rebuild as it just came out of storage and I will begin working on it as soon as it gets home.  I am planning on a full engine rebuild and will be splitting the cases and starting from ground zero.  The bike will be made into a fast and fun road going bike to ride around town and in the mountains, with occasional quick highway stints to get where I need to go.  I have tried to research as much as possible, but have a couple of questions for you knowledgeable folks.  My questions are:

1) Is it worth acquiring an RD350 transmission for that extra gear and the ratios?  Seems there are used pieces available, just wondering if it is worth it or not while everything is apart.
2) Is it worth acquiring an RD350 top end for the reed valves?  My understanding is that these are "better" but not sure of the logic or reasoning?  I assume I would need to purchase cylinders, head and pistons to make the swap, but that it should swap over pretty easily.  Please enlighten if I am incorrect.

It looks like this is a great forum and I look forward to learning as I go.  I will certainly share my progress once I get into it!  Thanks.

Mike

[old-too-smoker]

I would not bother with RD parts, stick with the R5 trans and cylinders. Back in the day I used to put modified R5 cylinders on later RD350 and 250's. The piston port was used on the TZ and R5, was my preference, though nothing wrong with reeds, smoother power band compared to piston port.  I thought it sounded better and had that surge that the reeds did not. I have owned many R5's, rode one as my daily rider for 5 years until recently when I sold it because I finished another RG500 project bike. 

[m in sc]

if you're tearing into it, do the 6 speed transmission for sure. I look for 6th constantly on my r5, and whenever i get into the motor i'll swap it.  theres been discussion on how to do this on here before. its def worth it especially for going on the highway.

As far as going with reeds? depends on what you want. I like an r5 as a rider for sure, but for serious balls out hot rod, id go reeded top end.  Lucky for you R5 pistons are available, they weren't for a LONG time.  But an R5 with chambers is a fun use-able nimble quick carver.

good shocks and tires are a must. also, swingarm bushings etc. 

[bitzz]

Transmission for sure... the rest? Why didn't you buy an RD if you wanted an RD?

If the bike has been sitting for any length of time, you're splitting the cases, so swapping in a trans is no work. If I was doing it I would use an RD400 seven plate clutch, and better ratios... but that's just me....

[Coop07]

Thanks everyone so far.

Reason I got this bike is that it was a really good deal and I really like the look of the front drum brake.

So it seems the transmission from an RD350 is a direct fit and a pretty good idea.  What parts are needed to fit the RD400 7 plate clutch?

Thanks.

[m in sc]

keep in mind with a tranny swap you need the drum, shift pawls, and shift shaft and shift forks, its NOT just the shafts and gears. 

to do an rd400 setup you need a 400 trans and clutch. to do a 350 7 plate clutch you need a late (post mid 74) clutch basket and setup. you should check out the clutch thread....

http://www.2strokeworld.net/forum/index.php?topic=1304.0

[AAAltered]

....I really like the look of the front drum brake.

Me too

[bike buff]

I would not bother with RD parts, stick with the R5 trans and cylinders. Back in the day I used to put modified R5 cylinders on later RD350 and 250's. The piston port was used on the TZ and R5, was my preference, though nothing wrong with reeds, smoother power band compared to piston port.  I thought it sounded better and had that surge that the reeds did not. I have owned many R5's, rode one as my daily rider for 5 years until recently when I sold it because I finished another RG500 project bike.

Perfect... Exactly what I did to my R5. Keep it as it is and enjoy what Yam gave us in a piston ported engine and 5 speed trans. If you need a RD, buy one and ride it rather than turning a R5 around. There are many Reed valved machines available all around us.