Messages

To replace the lab seal you have to break the crank down... you'll need a press. I think the hardest part of that will be finding a replacement seal.
If you have an "original", never serviced RD350 crank, it's time to do something with the crank. Bearings DO NOT last 50 years, even in a box on the shelf.

...but for that price you could have something custom made... that is a lot lighter

That's not a RD-LC swinger
They look like a dirt bike swingarm, like this:

... sorta copied from a TZ-F or a YZ

From a handling standpoint you want to add some wheelbase to your RD350, RD400 and XS650 swingers add about 1 1/2" and are bolt on, laying the shocks down a bit helps too, no more than 45 degrees though.

I have a CMR swinger, 4130, takes a 150 easily (this is for a TZ-G, but he does one for aircooled dual shock RDs that is mostly the same

Yeah it's steel. After much argument on my part, I have been convinced you want a (properly designed) steel swing arm. We all want a stiff swing arm, but they flex, no matter what you bolt on there. To make a swinger that doesn't flex would be weight prohibitive. A steel swing arm will return to it's original shape faster than a comparably stiff aluminum one. (This doesn't apply to a big modern cast super sport swingarm, they're so big they just do not flex... but would look really stupid on a RD350)
... all that being said: if you're after actual real "performance" you don't want a big tire; the frame can't take it, the motor doesn't need it and they'll slow you down. 
And the DG swing arms are a bad joke.

The TZR wheels I had were really narrow, like 1.85 front, 2.50 rear and had a single 300 or 330mm disk on the front and a 8" rear disk

I bought them cuz they're TZR wheels, but could never find a use for them and ended up giving them to buddy that used them for TZ125 rains

There's issues....
A "G" had a aluminum swingarm and shock... and a "low boy" frame
Here's a  "G"

$12k for "G" is about what I'd expect (If you're gonna race a TZ, you want a "G"... or a CMR)
I think this is an "E" (try not to notice the engine mount on the top of the case... that was dis-continued on the "C")

As I understand it, you want the higher levels of ZDDP on any non-roller cam valvetrain.

You WANT about 1100-1200 PPM ZDDP. Too much ZDDP is a BAD thing.
Most motorcycle oils have about that level of ZDDP, any car oil advertising elevated ZDDP levels should have that much ZDDP. "Normal" car oil has about 800-900 PPM. ZDDP clogs car cat converters.
ZDDP is a lubricant of "last resort", if all else fails, there's still ZDDP... or boron or .... The idea is if you wipe all the oil off a metal surface (run out of oil), there is still a coat of ZDDP. You don't WANT to use the ZDDP... but it coats all metal surfaces, not just cam followers, mains and big ends too.
ZDDP is not the be all and end all of oil choices.

And the two things that have changed the most since these bikes were built is oil and tires. When these bikes were built; there was no "gear lube" and they were designed to use Reg 30 oil in the trans, not because it was GOOD, but because it was available everywhere. Gear lube is BETTER... you can build a gear lube with more sheer and less lubricity than a motor oil, that works better in a transmission.
IF you are going to run gear lube: you MUST use GL4, nothing else (use GL3 if you can find it, but GL3 was superseded by GL4). GL4 has lower levels of sulfur, the bright metal in the trans doesn't like sulfur. So no GL4/GL5... must be GL4.
Viscosity is rated differently in gear lube than motor oil... so a 75-80 gear lube is about the same viscosity as a reg 30 motor oil... about.

All the good stuff?
Where's the pipes? carbs? brakes?  That's all good stuff.

If this thing was complete... and a little less crusty, it would be worth the ask.

If anyone is looking for a TZ with all the good stuff: get in touch

We can't log in to your gmail

maybe post your password

... been down this road before. Too bad i don't remember where the road went.

The RD was built through the introduction of tubeless motorcycle tires. The 1A1 bikes are not, the Daytonas might be.

The first tubeless rims were denoted as tubeless, they had either "tubeless type" or "TT" cast into the rim. You can also tell if they are tubeless type by the hole for the air valve: tubeless have bigger holes.

... and in case you didn't know: RD rims are a knock off of Andrews rims... 'cept Andrews rim don't weigh as much. RD rims are boat anchors

The final RD400, the 3J7, the F and G models in Canada (and there was an Australian model 3M4?)had the same taper as the later RD-LC or RZ.
That final crank looked more like a TZ crank than a RD crank... it had holes in the cheeks and no heavy metal for balance... and the key was 90 degrees off... and I think the pins were serrated (I don't remember)


Before the F and G models, the Canadian RDs and the US RDs were the same

The problem with racing that is it isn't going to be competitive against a more modern TZ750, with a modern frame... and tires... and wheels... and brakes... and cartridge forks....

Looks cool though

$35,000
Who says prices are depressed?

If it's already been welded, you need someone that actually knows what their doing to try to rebuild it.
It MAY have been welded because "Racebro thought he was dealing with a 100hp bike or something,..." OR it was welded because it was loose when it was last taken apart.
We were talking about what press to use... when I take them apart, I find they take (IIRC) 5-7 tons to press them apart, and they POP when they come apart... That's a good one that can be pressed together. Then OTHER ones take a couple of tons and just kinda smooosh apart... THAT one gets welded.
If done right, just grind out the weld, and start again. There shouldn't be GOBS of weld, you only need a tack or two.
I have often said that anyone with a brain and a press can rebuild cranks... then I saw some of the abortions done... so I have to retract that statement. I have seen new, aftermarket cranks that had to be trued. Rebuilding cranks is simple, but kinda finicky... I guess it takes practice.
Use stock RD400 pins, they're serrated, so they hold better. Wiseco makes hollow pins if you're doing a performance motor. Wiseco and Suzuki offer silvered big end bearings. ProX rod have a split big end, like the TZ rod, that oils better... again IIRC (I don't do a lot of RD350s, I'm a TZ or RD400 guy)

The first time I saw that frame I had to have one.
Got in touch with my good friend Denis Curtis, of CMR fame, to build me one.

So as it turns out: they couldn't keep rings in the thing. The frame set up a sympathetic vibration in the motor that made the rings flutter. If the rings lasted the whole race, the bike probably won, but the bike dropped out of a lot of races with ring/piston failure.
... and that's why they only made a couple of them. Coolest LOOKING TZ frame out there

1975 King Kenny won the Indy mile (dirt) on a TZ750.
At the end of the race Chris Economaki rushed through the crowd for his comments, Chris pushed the mic into Kenny's face and King Kenny said to the world "They don't pay me enough to ride that thing".
... and the bike was banned.