1981 Yamaha RD350LC

I found this unfinished project on the North American RZ350 Owners Group on Facebook in Oct of 2021. I was really looking for a KR Yellow & Black RZ, but the familiar blue and white paintwork struck a nerve. True, I already have two 350LC’s, but this ‘Bounty’ (blue and white much like the wrapping of the famous UK chocolate bar) would make a full set of colors. Even though they were never for sale in the US of A, and their following here less than tiny- I still think it’s an investment. Cue cat calls of ‘Idiot!’. I prefer dreamer, but seriously, my thinking on unfinished projects is by their very nature they are likely to be more affordable to me and I hope to use my homegrown and questionable skill and judgement to bring it to it’s final conclusion. That’s my investment.

This is the one I really yearned for in ‘81. The guys who had them were the ones who had left school on their 16th birthday (standard procedure in some parts of the UK) immediately secured jobs on farms or in construction and by 17 had saved enough for a downpayment to pay for them on the never-never, rather than me who had taken the frugal path of further education leading to practicing law (never happened) meaning that for a while my life was to be full of stress and beer and Pot Noodles and I was no more likely to have one of these as owning a Ferrari and going out with Bo Derek.

Below: everything you need to build a 1981 Yamaha RD350LC

Frame was partially assembled...loom in place.....

bolts, cables, airbox, front brake system still fully connected with decent stainless braided lines etc.

looking forward to opening this one up....

I spent some time hunting around for the swingarm only to find it connected to the frame. duh. However chain guard and center stand are MIA as are answers from the seller as to why....

The before pic..it doesn't look so bad! Only issues appear to be: look- no chainguard! And I'm pretty sure there's no center stand there either. Seller is innocent of forgetting to include something that didn't exist-- or telling me that, but that wouldn't have changed my mind to buy it. Going rate for center stand in April 2023. About $500.

the reason behind the nickname of the blue/white color scheme.

This is how the frame arrived with not a scratch......

....and the rest. U-Shipper delivered all from a trailer full of junk.

Brakes

this is actually wrong, the shim should go against the piston

Brake Rebuild

This bits are back from the powder coaters

the thing about getting things powder coated is that they blast them clean first...so this is in perfect condition.....

....to receive the piston. MUST make sure you clean them thoroughly though. Don't want any media left in there. Using the original piston as it's in great nick. Thin layer of red rubber great helps it slide past the rubber seals.

using brand new black HEL braided lines....

still missing that one shim. my version on the right...from the (thicker) bottom of a coke can. not great

bloke on ebay UK came thru with an OEM piece. $6

Carburetors

These were the first components to be singled out and stripped for blasting

good to see carb tops unmangled by vice grips

Running 210's which is 10 below the standard for this model. They should be 220's.

tickover screw complete with spring. sometimes....never mind.

Will need a new knob for this. Norbo has black or silver billet ones.

All carb details match the specs of a 1981 RD350LC (H) exported to Canada. (4Y3) EXCEPT...the main jets are 210's not the spec'd 220.

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Carb—Rebuild

Carb: 4L0–01 Tube: P2 345 Main: 210 Pilot: 22.5 Needle: 5K1 3rd Notch Slide: 2.0 Choke: yes I have a brand new Mikuni one. Spares to order. I made a mistake of ordering a carb rebuilt kit from Yambits. None of the parts are authentic Mikuni and there's a general understanding to steer of any carb components that don't come from the original manufacturer. That being the case - of everything the kits provided i only used: -o-ring on valve seat -float bowl gasket -float bowl drain plug seal washer -c clip for throttle guide I got the OEM rubber tops and washers from Norbo.

Again, it's these specs that match withwhat's in the carbs apart from the 210 jet. Anyone 2-stroker knows that leaner isn't better...and I need to look for some 220's....

....kind of ironic that I appear to every ever other size. The Yambits kit came with 220's but I don't trust them....

Vapor blasting is the only option on carbs. I've thrown many carbs into ultrasonic tanks only to have them come out with a full matt gray finish. no bueno.

Original valve seat goes into place with replated holder and JIS screw. Also the cleaned and polished.P-2 345 emulsion tube.

...then the 210 jet it came with...have no idea how it ran because the bike came to me dismantled.

Engine Teardown

Operating table awaits. This will be only my sixth engine I've totally stripped and rebuilt. I've done 3 H2 triples 1 RZ350 and this will be my second LC.

I think it could have been skimmed....will have to research how to tell.

underneath the carbon is a 0.75 stamp. Maker is Pro-X. Made in Japan

one way to hold the crank in place while undoing the stator nut and crank pinion

I know. I should have cleaned this engine first. in my defence, it's I'll likely be renewing everything though.

Engine Rebuild

Looks like original pistons were YPVS. The bike arrived in pieces so I never knew how it ran.

Best rebores at PJME https://www.pjme.co.uk/

look carefully at either of these pics and you can see great care was taken in chamfering the edges of the ports

Made in Japan Mitakas....there's a difference apparently if yours were made in India.

Went for OEM Yamaha small ends versus what came with the crank.

Clutch Basket Replacement

SWITCHGEAR

Wheels

Tail Light

Front Forks Rebuild

Fasteners

Measuring and recording all the pieces before they get dropped into Evapo-Rust overnight followed by a brisk wire brushing before they get dropped off at the platers.

Trying to be as detailed as possible. It may, literally, be years in between the time I get to work on it. That’s never the plan. Of course I want to build it continuously, but, life happens, alternatives exist.