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Not 2 stroke related, but I'll stick my neck out anyway....On my XS650, I have a pair of Mikuni RS/TM34 flatslides, and want to run pod filters, mounted on velocity stacks. I already have made a smaller battery box to allow this.
I actually ordered a pair of UNI filters with a 3" neck ID, 4 " long. Unfortunately, these filters have an internal ridge that do not blend nicely with my velocity stacks, so there will be no benefit from the nice entry radius of these stacks.

So what I am looking for is pod filters with an unobstructed 3" ID, max 4 3/4" (120 mm) OD, and length max 4" (100 mm) excluding the neck.  All suggestions welcome 😁

I am now converting my RD 350A to cable actuated rear brake, and replacing the passenger peg/ muffler brackets with some alloy brackets that only mount to the 2 M8 lugs each side
This makes the stock swing arm bolt 10 mm too long. For now, I'll use aluminium spacers, but a 10 mm shorter bolt would be much better.
So, will a bolt from an other model or other brand fit?
Maybe TR350 or early TZ?

Bummer! Maybe one of the most advanced 2 stroke otto engine product lines is axed as of just now:

https://www.soundingsonline.com/news/evinrude-production-comes-to-an-end

I was serieously considering buying an Etec 90 to replace my fuel guzzling Mercury 90 ELPTO carburetted 2 stroke outboard. All 90 or 100 hp 4 strokes are just ridiculously heavy compared to the Etec or my old Mercury, and that extra weight would flood the self draining cockpit sole of my Quicksilver 550 WA when anchored or drifting, like when fishing etc,

I have a 90% finished Suzuki 125 project, originally for my youngest son. A GN125, now with a shortened fork, 18" spoked front and rear wheels,  143 cc Wiseco big bore, etc, etc.
One of the really poor aspects of this bike is the original  front brake. A tiny disc and a single piston caliper setup just is not enough, even for its 70 mph or so top speed.
So I am looking for a better caliper, ideally 4 piston, alternatively 2 piston sliding type. Most sport bike calipers are just too large (Yamaha blue spot, Bremobo, etc)
Any recommendations for LH side mount, behind fork slider caliper? Disc size should be in the 240-260 mm region, but I want to source a suitable used caliper first.

Maybe a silly question, but it is related to my Higgspeed pipes with what I believe is oversized headpipes, 41 mm ID.

I have been planning to machine two tapered pipe sections to replace the straight section of the headers, then cutting a wedge out of the bend, squeeze it back together, and tig weld it shut. Ideally without cutting the headpipe to diffuser cone weld, but if required, I'll cut and reweld that too.

So my question is this: If I cut out a wedge on the INSIDE of the bend, what will happen to the bend when closing the gap? Will it tighten or will it open up? And what if I cut&shut on the outside of the bend?

Not my RD350, but definitely related and applicable, if scaled appropriately.

My stock 2.15x18 77 XS650 rear spoke/drum brake wheel, with axle, adjusters and a 60% worn Pirelli MT60 120/80 weighs 17.35 kg.
My 2.50x18 wheel for the XS, with a Talon MX hub, a 250 mm disc, Brembo caliper, caliper bracket, axle, adjusters, and a new Avon AM26 120/90 tyre weighs 15.55 kg.

That is 1.8 kg or 4 lbs less unsprung weight, when fitted with a SIGNIFICANTLY heavier tire.
IIRC, the weight difference between these two tires is close to 2 kg, or another 4 lbs.....

So, surely, with a 200 mm-ish disc, one could easily save somewhere between 3 and 5 lbs from an RD rear wheel. And there will be additional weight savings from the brake pedal/pivot as well.

Actually, there is still a pretty good selection of pipes for our old bikes.
High end pipes like JL, Spec 2, Milennium, custom builds , etc.
And also more basic pipes like DG, Higgspeed, Allspeed, etc
And several options from Japan, which few have much experience with, AFAIK.
Do any of you have any experience or opinion of how the different pipes would work on a stock or near stock ported 350?

As I totally prefer moderate rearset pegs, instead of the (too far forward) stock peg position, I am now considering converting the rear drum brake on both my XS650D and my RD350A to cable actuation, instead of the heavy and clunky stock brake shaft/arm/stay, plus the required linkage between rearset pedal and the splined brake arm shaft.

DCC, and some other vendors are selling some setups, and on those, the cable ends up in a fairly severe S shape. Basically pointing aft, then down, then aft.
On drum brake Yamaha roadracers, like the TR3, the cable went up in a smooth arc, then down. Obviously, the rear brake plate was designed for this cable path.

I am thinking about having the cable point down at the pedal end, then arcing back towards the brake drum. Just making a pedal that is more or less straight, instead of L-shaped. That way, I can have the stopper for the cable sleeve on/attached to the static brake stay, which is the most convenient.
I believe there are two main objectives here, minimizing cable friction, and minimizing any feedback of suspension movement into the brake. Feel free to provide suggestions, constructive criticism, and ridicule:)

I am using a TZ replica fiberglass front fender on my RD350A, currently without any fork brace. The fork is the oem 34 mm KYB, but with RaceTech linear springs, and emulators.
I know some claim that the original fender mount bracket also works as a fork brace, although I haven't noticed much difference myself, riding the bike.
Have anyone for example measured fork twisting, with and without the stock fender installed?
Basically by locking the front wheel in position, then pulling or pushing on the handlebar end, and measuring deflection.
Or even better, having a complete, assembled fork, with triples and wheel axle, with a dummy spacer instead of the wheel hub,  all fasteners torqued to spec. Then clamp the axle/spacer securely, and use a 7/8" round bar instead of the handlebar, and again pull or hang something heavy from it, then measure deflection with and without the stock fender installed.

I am thinking, if the stock fender really doesn't do much, then adding a pound/ half a kg of unsprung weight really makes little sense.

Due to the corona situation, I ended up staying on my ship another 5 weeks or more, instead of going home two days ago. Which means I have more time to play around with various ideas, most likely good and bad.....
For me, reducing the weight of any bike is always a goal, especially on already light bikes like my RD350. So I was just surfing around on eBay, and came across loads of carbon fibre seat posts for bicycles of all sorts. (Bicyclists are worse weight fetishists than even the most hardcore motorcycle builder).
These seat posts are basically a carbon fiber tube, with a seat mounting bracket at one end. I am pretty sure one of these seat posts could be used for making a very lightweight side stand. Just cut to length, glue in an alloy or plastic pad at one end, and an alloy adapter/socket at the upper end. I will definitely order a couple of cheap seat posts just before travelling home, whenever that may be.

Hi,
I suddenly found myself in the middle of a 10 week offshore stint, instead of at the very end of a 5 week period, travelling home today.  So the only sensible thing to do, is to surf the web for cool motorcycle parts to spend the extra overtime money on :)
One thing I have been looking at, is headlight ears for the RD. The stock ones need to come off for straightening and paint, and I need something in the meantime. Moto Lanna has a great selection (for SR and XS), but I can use shims to compensate for the missing millimeter.
So my question of the day is:  What is the distance C-C from fork tube to indicator stalk bolt, on a stock RD350A headlight ear?

On the XS 650 forum, CruzinImage gets very good reviews for their pistons, which are the least expensive pistons available for an XS650. They also have RD 250/350/400 pistons, rods, etc. And the prices seem very reasonable IMHO.
Obviously, we are not talking about upgrade parts here, just aftermarket replacements for the oem stuff. they also have parts for many other brands, not just Yamaha. Definitely worth a look if you are on a budget!

https://www.cruzinimage.net/

Does anyone know what bike this alloy Kickstarter is off?

I had Danny (27Cycles) build me a 2" extended round tube swing arm some years ago. And it is really nice, and actually lighter than the stock swing arm as well.
Now is the time to finally fit it to my mostly stock RD350A. Moving the rear fender back 2" (51 mm) is more or less a simple matter of making some SS or alloy brackets.
But the chain guard is a bit trickier though. This swing arm has the shock mounts in the same location relative to the swing arm pivot (i.e. the 2" have been added aft of the shock mounts)
So I basically need a chain guard that is 2" (51 mm) longer aft of the shock cutout.
The mounting bracket location are of minimal importance, as I will need to TIG weld some chain guard mounting points to the swing arm anyway.

Some of you may know of this build from before, I just stumbled across it on a XS650 forum I spend some time on.
http://www.xs650.com/threads/new-700cc-outfit.52876/
An impressive build, I'd say!

I decided that I wanted a more secure connection than having the Y-boot clamped around the filter neck, so I used a filter with a larger neck, and turned an alloy adapter. I guess the pics show what I did.

Inspired by another thread, I started thinking about cable actuated rear brake with rearsets on my RD350, using a pedal like older TD/TR racers. This would give a much lighter and simpler brake setup IMHO.

I wonder if a cable setup would require an additional return spring on the brake arm, to ensure it returns?
Venhill in the UK have cables, and the pedal is easy to make.

Hi,
I am planning to buy a TI front axle nut for my XS650 project, and found that the XS nut is M14x1.50.
Now I wonder if the RD axle nut is the same, so I can order 2 at the same time?

And if someone knows the thread diameter and pitch for the RD350 rear wheel axle nut as well, that would be a welcome bonus!

As usual, all these questions pop up when I arrive at work, thousands of km from my garage and bikes....

Hi all,
2 years ago, I bought a pair of SS Higgspeed chambers for my 350. Although shiny and neat welds, I am not tohappy withthem. Definitely way too noisy. So I cut off the 2" muffler bodies, and got some 65 mm tubing to use instead, to allow more muffler packing. I also plan on using internal stingers, extending to the fwd end of the baffle cone.
Here comes my question: Will the sideways/vertical locationof the forward end of the stinger matter much?  Power and noise wise?
For the look I prefer, I want the tail of the pipes low and tucked in. This would place a straight stinger towards the outside and top of the baffle cone. Maybe even close to running paralell with the baffle cone wall.

The stock front fender on my 350A got lost before I bought it, so I have used a TZ type fiberglass one for a while. I never really liked that look, so went shopping. Yambits do not have repop 350 front fenders, but they have 2 versions for RD400s. Yesterday, I received the cheaper one of them. Looks good, actually, but feels really heavy. So on the digital kitchen scale it went. 1680g!! Almost 4 Lbs!!
I now wonder if OEM chromed steel front fenders are equally heavy. If someone could weigh their 400 fender, or even 350 fenders including the stays, it would be great.
Just to compare, I also weighed a custom alloy front fender for my XS650, that I had made byThe Tank Shop in the UK. It weighs 544 g (1 Lb 3oz) A pretty massive difference in unsprung weight, I would say. And that alloy fender is pretty close to stock size, not a cut down version. Now if someone could make a CF front fender for RDs