Messages

I've never measured a Vesrah base gasket but I doubt they would be that thick.  That is more in the size of a spacer than a gasket.
Lyn

The number of teeth on the primary gear are the same for both engines, 23T, and either gear will work, however the RD 400s all have the groove machined into the back for the O ring to prevent oil leaks where the early RD 350s did not have that feature.  Some of the 350 primary's leaked oil pretty badly and caused a fair amount of smoke from the right side pipe if you did not use Yama-bond to seal the gear in place.  So, use the 400 if available.
Lyn Garland

I replace them when they break or chip and I find them during routine maintenance.  Mine don't get a lot of mileage, but that they get is hard.  I've only had one or two break over the years.
Lyn Garland

I sell three thicknesses of base gaskets: .22mm, .35mm, and .56mm.  The .56mm gasket is stock thickness.  The thinnest gasket is made from sturdy material and works well, but it is for adjusting squish clearances much smaller than yours.  You need to send your heads or cylinders to a quality machine shop to alter the sealing surfaces to close up that gap.  If you are going to modify the engine
in other ways in the future you should probably wait and do everything together.  BTW, just closing up the squish clearance won't give
you a noticeable increase in power.  It will however, reduce the chance of detonation and engine destruction. 
Lyn Garland

Thanks very much for your info.  We just might be in touch for more hands-on help down the line. 
Lyn

Can the oil pump from a RD 350 be used on a RD 400?  I know that the pumps are different externally, drive ratio's, etc, but with the proper drive gear will the 350 pump work on a 400 engine?  I have three or four 350 pumps and a fellow on the Forum needs a pump for his 400 but has been unable to find one.  Can we configure one of my 350 pumps to work on his engine???
Lyn Garland

That's a beautiful and very competent motorcycle, but IMHO it is a niche bike.  It's place is on the race track or parked at the curb at a coffee shop or bar.  It sure ain't no street bike.  Boy, would it be fun on the track, and a front runner too.
Lyn Garland
PS:  $6K is cheap.

I finally got around to this. I wish I didn't! Got the bushings pressed in. Now the little stubs won't fit.
Should I get the bushings machined? It's like .2mm off.

If the bushings are fully seated in the swing arm, a long reamer, preferable with a pilot at the other end is an exellent tool to correct the inside diameter. I am sure it can also be done in a good pillar drill, or a milling machine.

I always used an automotive brake wheel cylinder hone to relieve the clearance problem.  It doesn't need to be precise, just a good snug fit between the bronze bushing and the steel sleeve.  I used an electric drill and probably cutting oil as a lubricant but that was years ago and I can't be sure about that. 
Lyn Garland

That is a good brief description of the squish band and the value of the correct clearance and angle.  The picture is of a Kawasaki combustion chamber which doesn't have as defined a squish band as the RD squish band.  Optimum squish clearance for the RD 400 is from .034" to .038" and anything over .040" is excessive.  The squish band angle needs to push the fuel mixture out of the edge of the cylinder into the center so that is no fuel trapped at the edge of the piston that can ignite/detonate and cause damage. 

Most engine tuners can turn heads and adjust squish bands.  Scott Clough, Chuck Quenzler come to mind immediately.  Maybe Ed E, but I'm not sure he has the equipment to turn heads. 
Lyn Garland

I had a Daytona Special many  years ago and liked it very much.  I removed the emissions equipment from the exhaust system, replaced the carbs with the older, 1A1 style carbs, and set the timing at 2.0mm BTDC and the bike ran like a dream.  It was just used on the street, I never had it on the track, and I put a lot of miles on it.  Sold it to buy a BMW 750. 

To answer your question:  The cylinders do not do well with serious porting.  The transfer port arrangement is low giving a nice torque curve for a street bike but not so good for a performance engine.  The cylinder casting is such that you cannot raise the transfer port enough to correct that design feature.  You could, and some tuners do, mill the top of the cylinder two or three millimeters and then fit a spacer under the cylinder to raise it.  You can then lift the transfer port enough to balance the porting and get good blow down.  Of course, that raises other problems, combustion chamber work, and with the DS probably separating the head, but the cylinders can be made to work.  I have also heard, from some tuners, that the transfer ports themselves are better on the DS cylinders than they are on he 1A1 cylinders, but I have no experience with that.  As mentioned in the other post, the 2R9s are the best.
Lyn Garland

If you will post the VIN I can tell  you the year.
Lyn Garland

The Service Manual calls for a 5I4 in the 3rd position and a 140 main jet.  Also a O-8 needle jet and a 25 pilot jet.  That was for a stock machine and gasoline back in the dark ages.  The 3rd clip position on the jet needle is counted from the top.  YMMV.
Lyn Garland

None at all; in fact that is better.  You know forged pistons require more (looser) clearance, right?
Lyn

Yes you can.  You might want to think about it a bit, i.e., you should match brands and types as much as possible to minimize possible problems (except in an emergency) but they will work.
Lyn Garland

Let us know how the master cylinder comes out.  The bleeding should be a piece of cake.
Lyn