RD350N1 Mild Restoration / Build Thread

[mangocrazy]

Look forward to this, for info my other business has a trade account for YSS shocks so if you need a price for one send me a part number and I’ll get you the price

Excellent, cheers - I have the shock wating to be fitted, but have done nothing about sourcing stuff for the front end yet, so will be after springs, and cartridge emulators too , if they do them for this

Pretty sure YSS do cartridge emulators and springs for the YPVS. I fitted some emulators to the (even more spindly) forks on the LC and it made a noticeable improvement, as did the YSS shock. I found the shock to be a bit harsh until it had bedded in, but now gives good control.

[GENT]

The N1 is a lovely bike - i may be biased to be fair.
Here is me / mine

[lostboy]

I think the N1 (and N2) is probably one of the best looking bikes ever made, as soon as I see one I get a nostalgic pang for happy days when I was a youth and summers lasted forever.

Amen.

[Le_Fromage_Grande]

The LC2 is the best looking bike ever made

[Couchy]

The LC2 is the best looking bike ever made

Had mine when I was 17, happy memories of that bike

Here it is hidden behind my bro AE50, don’t have many pics of it, this would be 1984. After 30k miles several crashes and blow ups it was part exd for an SRX600 which tbh was also a good bike

[Le_Fromage_Grande]

I had a blue TS50ER like the red one in the background in 1983.
I didn't get my first LC2 until 1990 when I was 22, I couldn't afford one till then, lovely bike, I only really used it for a year and then bought a 1985 GSXR750, but I kept the YPVS for another 3 or 4 years even though I wasn't using it, wish I'd never sold it.

[Tricky]

@GENT pinging this thread and the subsequent posts has spurred me on, so the LC has at last made it on to the bench!

Unfortunately just as I was about to set about it ( engine top end strip is first on the agenda, immediately followed by rear end out to sort the swing arm paint, give the linkage etc a good go through and service before reassembling with new shock as a minimum) , another part of life intervened meaning I've got to shoot out now so seat off is as far as I've got - this is how it currently looks



I'm busy tomorrow, but then got a clear couple of days so watch this space- I for one will be interested to see inside the motor and whether it is still on the original pistons, as going from the externals and milage/history as much as I have it, I think it may be

More to follow - soon!

[Bigyin]

@GENT pinging this thread and the subsequent posts has spurred me on, so the LC has at last made it on to the bench!

Unfortunately just as I was about to set about it ( engine top end strip is first on the agenda, immediately followed by rear end out to sort the swing arm paint, give the linkage etc a good go through and service before reassembling with new shock as a minimum) , another part of life intervened meaning I've got to shoot out now so seat off is as far as I've got - this is how it currently looks

Its progress and now its on the bench it will get done quicker

Only ever had an RD250LC and realised i dont have a single photo of it as all were probably in a box that got misplaced during one of my parents house moves after i joined the military at 21. Every bike picture i had from age 17 to 21 was in that box

[Tricky]

Working on these old bikes is so good, no faffy fairings or unnecessary / unusual clips or fasteners, just standard tools and they are in pieces in no time- life was so much simpler back then, I love it!

Anyway, the LC motor is now is pieces-you can of course usually never really be completely 100% certain with something of this age, but now I’ve got it apart, I’m now as sure as I can be that this is the first time this motor has been in pieces since it left the factory- well, the top end of it anyway, which is as far as I’ve gone, and TBH as far as intend to go with the engine strip now.



All of the fasteners are the originals, they didn’t look or feel like they’d been moved before, and it’s on standard bore with genuine Yam pistons, and everything thing else as far as I can see.

And it’s all good news - no signs of any detonation or any previous blowups in the head



There is a fair bit of carbon build up on the PVs and pistons, but everything was still moving freely, there were no leaks from the PVs and their bearings feel lovely, so they will get a good clean up and some new seals purely because of age, and will be good to go straight back in.




The bores are excellent, with no visible or measurable wear or damage, so I’ve dropped the barrels into my local vapour blasting man this afternoon, and when they're back they will get a new coat of paint and reassembled.






It was particularly pleasing to see that the reason that it is down on power and a bit flat is simply due to carbon/ gunge build-up;- the rings on both pistons are completely gummed into the grooves on the exhaust port side, and haven’t been sealing properly for a while I would guess, I knew it was down on compression, but of course, until you have it in pieces, you can never be completely sure of the reason




Whilst the pistons look to be in reasonable nick and I am sure I could likely get away with just giving them a good clean up and a new set of rings, they are almost certainly at least 37 years old and have done approx 15k miles, which is a lot for pistons in a smoker so they will be replaced, along with of course small end bearings and gudgeon pins etc

So, that’s as far as I’ve got at the moment.
I’ll get the swingarm shock and linkages out over the next few days and on the bench for a full inspection before I finalize the engine bits order, as I'll most likely include new bushes/bearings and seals for the back-end and wheels in it, and although I’m tempted to sort the paint on the swingarm myself as correct colour rattle-cans are readily available, I’ll most likely get it professionally re-finished- am currently mulling it over - we shall see.

Anyway, watch this space- more to follow soon!

[Taipan]

Awesome MAte, keep it coming !

[Le_Fromage_Grande]

The head is a lot better than mine.
I think I'd stick with the Yamaha pistons and fit new rings to them, the quality of all of the pattern pistons available is a bit dubious, I've bought Mitaka ones for mine, about £100 for a pair of piston kits, but I'd rather have the original Yamaha ones.
The Athena gasket kits are good quality.

[Tricky]

The head is a lot better than mine.
I think I'd stick with the Yamaha pistons and fit new rings to them, the quality of all of the pattern pistons available is a bit dubious, I've bought Mitaka ones for mine, about £100 for a pair of piston kits, but I'd rather have the original Yamaha ones.
The Athena gasket kits are good quality.

I hear ya- although I imagine the likes of Grampian and PJME etc must sell 1000s of Mitaka pistons and they can't be bad, I'm not convinced with the consistency of quality of them- I went off them after (expensive ) problems with my old KR1-S that I believe were down to the Mitaka pistons I put in it

The good thing with LCs though as I'm sure you know is how many piston options are available for them including OE still, due mainly to the popularity of the quads I guess, price-wise ranging from gen yam at the top end at ~£200 per side inc rings, pin etc, down to £25/side for hing-hong no-name type ones.

Dependant on availability, chances are it'll most likely get Wiseco or Vertex (which come out £100-£120/side), or new OE if not.
I had Wisecos in my 421, they're forged and the quality was lovely- one thing is for sure, the old ones are not going back in- they have more than done their time!

[Le_Fromage_Grande]

I've Wiseco forged pistons in my Kawasaki, the quality is superb, better than Kawasaki original ART pistons.

And 15K isn't much on a set of Yam pistons, certainly had 30K out of YPVS pistons with no problems, and I wasn't gentle with it, got a feeling they stayed in when it was stage 2 Stan Stephens tuned and running Lomas pipes, I never had any engine problems with it.

[Le_Fromage_Grande]

That reads like I'm trying to convince you to use the pistons already in the bike, I'm not, and I don't know why I posted that.

[Tricky]

A bit more progress on the LC yesterday, and this is how it’s currently looking


The disassembly process, as with the engine top-end was very pleasurable- everything easy to get to, no seized, bodged or non-standard fasteners, and all came apart lovely and easily- not something you can ever rely on with swing-arm spindles and shock linkages, etc on a bike of this age, but no problems at all here.


The linkage and dogbones are a bit grotty, but nothing that a soft wire brush in the parts washer won’t sort- all the bushes, bearings, and spindles still contained some grease, and are in really decent nick considering the age with no discernable play, roughness or corrosion to speak of so they will get a decent spruce up and "we go again", as all the cheesy footballers say




The original shock wasn’t too bad either- yes it's grubby but no oil leaks and even the little rubber belt that adjusts the preload is in decent nick- not that it really matters as of course, it will be redundant with the new YSS shock.


As for the swinging arm itself, the corrosion doesn’t look to be any worse than I imagined, so it will get a rub down, or maybe blasted, and I’ll give it a rattle can job, as a first pass at least, and will see where that leaves us.



I’ve just put an order in for the engine bits and a few other odds and ends, I’ve got the Multistrada booked in for its MOT today with the guys who are vapour blasting the LC barrels so hopefully they’ll be ready to pick up then, and I can start getting the old girl back together next week

[Tricky]

Little bit of an update- I haven't got the barrels back yet, but having said that the new pistons and gaskets, etc haven't arrived so it's not really holding me up , but in readiness for it all going back together I've done a little bit of cleaning - the head came up lovely with just degreaser and a green Scotch-Brite pad- the paint on it is original and save for a few chips, pretty much as good as new so it's ready to go back on



The suspension linkages came up lovely too, again with nothing more than a green pad and degreaser.



The swing-arm is nice and clean now and my Yambits order arrived on Friday with the right colour silver paint, so if I get a chance later today I'll get the wet and dry out and getit prepped ready for paint

[Tricky]

What degreaser do you use? I find all the modern stuff is a bit weak compared to the deadly nasty stuff that you used to be able to get.

Know what you mean and agree- this is what I used and is my default these days, works well and relatively cheap too at a tenner for 5l


https://www.screwfix.com/p/no-nonsense- ... 5ltr/88668

[Mr. Dazzle]

You can still get it, we use/used some of the proper nasty stuff at work. It's just the general public who are restricted. Even in a professional context it's a case of "why can't you use something else?".

Can't really fault it TBF, its a bit much to be asking your employees to inhale cancer fumes

[Count Steer]

You can still get it, we use/used some of the proper nasty stuff at work. It's just the general public who are restricted. Even in a professional context it's a case of "why can't you use something else?".

Can't really fault it TBF, its a bit much to be asking your employees to inhale cancer fumes

We used to get through rather a lot of Carbon Tetrachloride.

'Exposure to high concentrations of carbon tetrachloride (including vapor) can affect the central nervous system and degenerate the liver and kidneys. Prolonged exposure can be fatal.'

[Le_Fromage_Grande]

That head is superb, I don't know if I've ever seen a used YPVS head as nice as that, all the ones I remember seeing had evidence of mild detonation.