1981 Yamaha RD350LC rebuild [Archive]

eelracing

13th October 2013, 14:40

My first ever big bike I brought was a second hand RD250LC.How I loved that bike even tho every second weekend usually meant a respray for the pipes from the inevitable lowside.
But I didn't care I worshipped that bike until the day some plonker told me the 350 was the one to have.
But alas I never did discover that pleasure as a serious RG250 addiction and all things Suzuki took over.

That was until 8 years ago and a chance encounter across this rough but quite surprisingly unmolested example came to be in my possession.
She started on the second kick and those long ago memories came flooding back as that sweet smell and LC burble at idle hit home.
A test ride later it was obvious something was seriously wrong as it couldn't pull past 6-7000 revs into the giggle zone.Not to worry the price was a steal and she was mine.
A strip down revealed a Piston with a section of skirt missing and a dodgily wired up fuze box and a bent jet needle among others.
But that was where it ended as the RD was pushed into the far end of the shed and the intervening years were taken up with VMX and chasing SV's on an RGV.

Until now.A month ago the decision was made as it was either now or never as the excuses were wearing thin.
I hauled her out of the garage and into the spare room so no longer could she be ignored.
A rebuilt crank and top-end later the engines together and back in the frame.Tank and sidecovers are at the painters and I await some carb parts and electricals from Yambits in the UK (an excellent source for all things Yamaha)But i'm sure the real fun is only just beginning...

GrayWolf

14th October 2013, 08:10

YEhhhhhhhh!!!

Had a 350 (tuned), after my H1 it was a pleasure to ride, it handled, and was as quick (OK, quicker)... Love those old 70's/80's 2T's... good on you, look forawrd to seeing pictures of the finished bike! :clap:

F5 Dave

14th October 2013, 13:55

Good on ya.

Though check everything you get from Yambits carefully. I only ever hear bad things about them on the forums.

iranana

14th October 2013, 14:16

Good on ya.

Though check everything you get from Yambits carefully. I only ever hear bad things about them on the forums.

Beautiful bike, will be a blast to ride :D But I second F5 Dave here. Yambits is awesome for some things like rubber dampeners, bearings, gaskets and things no longer produced by Yamaha but do NOT use their carb kits. I've had first hand experience with them and they were trash - they sent me Keyster kits (and they don't tell you this, most annoyingly, they make it seem like they're sending you Mikuni parts). Don't use any after market carb kit for that matter, only use genuine Mikuni parts... EconomyCycle sells all the Mikuni you need.

I sent the carb kits back to Yambits for a full refund without any issues. I opened them up and measured the needles from the Keyster kit against the Mikuni needles that they were meant to be a replacement for, and they weren't the same thickness or taper. The jets aren't any better, and the machine work on some of the jets was less than acceptable (manky thread work)... The kit had the wrong size pilot jet in it too. Using the aftermarket carb kits might give you issues with tuning it (especially with those crappy needles). Everywhere I read that those Keyster kits don't cut the mustard, and after examining the parts they come with, I wouldn't bother trying them out. Good news is that they'll refund you in full (just pay for postage back). Or just use them for the gaskets etc.

Crasherfromwayback

14th October 2013, 14:36

Awesome Bro!

Arronduke

14th October 2013, 22:41

Own many a RD350LC and loved them all... until they either blow up or crashed.
Looking forward to seeing the finished result.

eelracing

15th October 2013, 12:42

Good on ya.

Though check everything you get from Yambits carefully. I only ever hear bad things about them on the forums.

Beautiful bike, will be a blast to ride :D But I second F5 Dave here. Yambits is awesome for some things like rubber dampeners, bearings, gaskets and things no longer produced by Yamaha but do NOT use their carb parts

Cheers for the headsup fella's and yeah buying aftermarket does have it's hassles and I realise that.But when Yamaha quote (and I shit you not they turned the screen around and showed me) $99 for a float seat and I can get a full carb rebuild kit from Yambits for 16 quid i'm prepared to take the plunge.It's arrived and the needle and seat in the kit seem fine but of course the proof will be in the tuning.
I am currently using a Keyster kit in my TS400 and it performed flawlessly in the last VMX season but as you can appreciate she's a single and easier to tune than a twin.
I did get caught out aftermarketwise with ordering three replacement indicators.The two front ones wired in no probs but the rear one's wires wouldn't reach the harness:brick:but simple enough fix and the original Yamaha rubber dampeners wouldn't fit inside the indicators...a Stanley blade and a bit of sanding down later and hey presto they fit.

But thanks for the EconomyCycle lead I will def check them out.

iranana

15th October 2013, 13:15

Cheers for the headsup fella's and yeah buying aftermarket does have it's hassles and I realise that.But when Yamaha quote (and I shit you not they turned the screen around and showed me) $99 for a float seat and I can get a full carb rebuild kit from Yambits for 16 quid i'm prepared to take the plunge.It's arrived and the needle and seat in the kit seem fine but of course the proof will be in the tuning.
I am currently using a Keyster kit in my TS400 and it performed flawlessly in the last VMX season but as you can appreciate she's a single and easier to tune than a twin.

Christ, I've never bothered to go to Yamaha and now I definitely won't! Yeah like I said I never actually installed the Keyster parts, I decided I'd rather not try since I could get Mikuni parts for a little more. If you need gaskets and a float needle/valve then it's still a great deal for the price even if you don't use the jets! I didn't need the gaskets etc, so I shipped em back and got a needle jet, needle, mains and pilot from Economy. I'm curious to see how they go in the RZ though. I hear both good and bad about em.

F5 Dave

15th October 2013, 15:31

Arronduke

15th October 2013, 19:39

I have spent quite a lot of money on LC's.
We are talking NOS, JMC swingarm... oh and yes the swing arm took 12months to turn up. So after about 6 months every Friday night no matter were I was and how much I had drunk I would try and find a phone to ring JMC the UK... and ask about my swingarm.

I don't think it made it arrive any quicker....:no::no::no:

I did another one were I put an RZ in to a LC.. but welded all the swing arm mounts in from the RZ. will try and find a picture before the cold kiwi... 20years ago.
.:(

F5 Dave

16th October 2013, 08:26

I've been reading about that same crap service from JMC for 20 years. Dicks.

iranana

16th October 2013, 09:26

I've never used them & hate people trashing businesses on the internet, but trawling the Yam forums you just hear bad things about gaskets, bearings & other things they supply. Enough that I'd have to be wary. Ahh heck its hard to get normal gaskets too wrong if they are the right size & cut to shape.

The gaskets I bought off em all turned out to be fine (bought a complete gasket set with all gaskets) and as for the top end bearings I bought... well, only time will tell I suppose. I'm running Mitaka pistons at the moment, but I'll be doing more work on the top end in the near future anyways. I hear good and bad things about Mitaka though, so I dunno. Don't buy anything 'chromed' off Yambits, either. Tends to be crappy and rusts quickly. Yambits do a great job in cataloguing all the bits and bobs for Yammy's, but the quality is questionable sometimes.

Just on a side note, the best prices and service I've ever had is from an eBay seller who goes by the name 'yamahardbreaker'. He breaks down Yammy two strokes and parts them out. Shipping is usually free within in the UK, so I use YouShop to send parcels from the UK to NZ at surprisingly good rates (thanks F5 Dave, if I recall correctly, you put me onto this). The exhausts I just bought from him cost only $90 to have shipped which is cheap considering the size/weight of the parcel and it took them about two weeks to arrive. Lots of what he has isn't listed on eBay, so message him for specific parts...

eelracing

21st October 2013, 11:38

But i'm sure the real fun is only just beginning...

Third kick and RD gloriousness smoked out the shed...and the neighbours:drinknsin

The manual specifically states not to be tempted to run pre-mix in a rebuilt engine.
But i'll be buggered if i'm gonna trust a 30 year old oil pump before i'm satisfied it's doing it's thing.
I need'nt of worried a couple of heat cycles and straight gas later she purrs like a kitten.

The tank and sidecovers should be ready this week...can't wait for running-in.:sweatdrop

iranana

21st October 2013, 12:18

Beautiful! Nothing quite like that puff of smoke from the pipes of a rebuilt smoker!! Are you running mineral oil or is it just rich as shit? I ran mine on mineral until I was on the motorway and realised I was smoking everyone out - the biker behind me didn't look too happy when he overtook. But good call on running pre-mix before checking the oil pump, tis the only thing standing between your smoker and top/bottom end destruction... Looking forward to seeing it all together!

eelracing

22nd October 2013, 00:02

Rich as a shit after a night on the turps.:lol:
What you see is the initial burning off of the rebuild oil and premix.
Once the pumped oil came through the lines she started running rougher than an arabs armpit.

I'm just waiting for a clearcoat to be applied to the tank and hopefully today should be able to collect.

Arronduke

24th October 2013, 02:05

Nice job, looks great.

Have not heard of the oil pumps giving trouble but like you I would add pre mix until the pump kicks in.

F5 Dave

24th October 2013, 08:19

Something I wrote on a dirtbike forum over a decade ago but kept the text:

Oil injection has the advantage that when you run out of gas in the middle of nowhere you can blag some straight petrol from the local farmer.

Many people slag off oil injection which works just fine in zillions of road bikes everywhere. These old world closed minded people cannot accept the risk that the oil pump mechanism will continue to meter oil reliably into your precious engine.

When I discovered (just in time) that my oil level of my old DT200 was not going down I became one of these people.

We meet on Tuesday nights.

eelracing

24th October 2013, 09:59

Haha got any membership forms???

Well the paint shop did an outstanding job,so good in fact that it makes the rest of the bike look shabby.
But this was always going to be a rolling restoration.

Everything has been going along swimmingly that it was just to good to be true.
Running in has revealed the same test ride prob...she won't pull past 6000 revs:angry2:
It's fine under these rev's (at running in speed:mellow:)and the manual points to the HT leads and spark plug caps.
But I suspect the CDI,stator and coils prob need checking over.Frustrating but not unexpected I spose at this age,bit i'm rapidly getting out of my depth.

It's the 2nd round of VMX this weekend so priority calls and she's been pushed back to the corner of the shed:facepalm:...:soon:

iranana

24th October 2013, 11:11

Looks beautiful! Nice job! If you find that the bike runs a bit ratty when you turn the headlight on and off, it could very well be an electrical issue. Check how much voltage your battery is getting, and make sure you've got strong spark, and that your ignition timing is set properly. Otherwise, I'd suspect the carbs and those pesky Keyster parts (if you installed them, that is)... If the Mikuni brass is still in good nick, could try chucking it back in and see how it runs. Does it bog down if you whack the throttle open? Any flat spots when you roll the throttle on and off? What clip is your needle on? Start in the middle and lean it/richen it to see if that helps - easy to do when on the go! If you still having problems, jump on 2strokeworld. Without the help of the folks on there my RD wouldn't run half as well as it does now!

F5 Dave

24th October 2013, 11:30

Well it sure looks nice.

roogazza

25th October 2013, 07:45

Crasherfromwayback

30th October 2013, 12:25

Well the paint shop did an outstanding job,so good in fact that it makes the rest of the bike look shabby.
But this was always going to be a rolling restoration.

:

Looks awesome Bro!

eelracing

11th November 2013, 16:22

Update

Well an auto electrician has been all over the bike and declared it fit for purpose,which still left me back at square-one.
There was nothing for it but to start from scratch again so a strip down of the carbs side by side later and viola...revealed a missing brass washer on one carb between the needle jet and main jet.So simple and obvious that I can't believe it caused so much grief.
Looking through the parts left over from the Keyster kit and sure enough it has one.

A test ride later and she pulled right through the rev range,but not perfectly as a plug chop indicated richness at full throttle.
A lowering of the needle's improved the transition into the top end but still not perfect,next size down mainjets are on order...as well as another keyster kit.
I'm going to deck out both carbs with these kits just to satisfy my own curiosity and keep everything mint.

So much happier now that I can start on getting her roadworthy and registered.
To do list includes brake caliper overhaul and braided lines,fork seals and definitely new tyres.

Arronduke

12th November 2013, 20:56

Nice job.

Great satisfaction find a fault like that.

Nice build, wish I had one.

(What I sold my 350LC for:doh:... and the spare parts I just threw away)

eelracing

5th December 2013, 21:15

Big day yesterday getting the bike relicensed and legal,it was a good sign when getting to the LTNZ station and having the techo's practically tripping over themselves to get her off the trailer.I even had a good old chat with a random guy who followed me halfway across town to get a closer look as he used to own an LC way back as well.Turns out he still owns a black and yellow TDR250 that he is putting back on the road.

She flew through the licensing no worries with no yet to do's on the list...sweet give me my license plate i'm out of here.
Today was spent just riding and 200 odd k's later I'm satisfied she's run-in.
Final jetting has still got to be sorted as there's still a niggly flat spot between 5-5500 revs...but it's nothing a quick two gear downchange doesn't fix:cool:

A few pic's between smoke breaks...

Arronduke

5th December 2013, 22:11

Nice job, I guess it up for sale now?
Shame its out of my league... but wait..

I would like a classic LC... tried many times and seemed to F#ck it up.

5yrs, interest free, take 3k NOW we have a deal. Hell to seal the deal you can experience my wife's cooking and my kids will practice their singing for the year end play thing. That you can have for free... make sure you have about 2yrs frees... that seems about right. Even then you might miss out on the wife's cooking... not a bad thing.!

Do we have a deal?

eelracing

5th December 2013, 22:50

Nice job, I guess it up for sale now?

Ha you be trippn' my man...she's a keeper.

A wise man once said the best bike in the world is the one in your shed...you know it,I know it,i'm just thankfull some don't know it.
There's bargains out there to be had.

Bender

6th December 2013, 07:37

Very sexy. Bring back two strokes.

F5 Dave

6th December 2013, 07:38

Good times

Crasherfromwayback

6th December 2013, 08:02

Love yer work mate she looks fantastic!

koba

9th December 2013, 19:22

Very cool! :niceone:

Fastmark

10th December 2013, 06:30

Congrats on a great rebuild, looks awesome. Had a 350YPVS which dollar for dollar was the best fun you could have on two wheels, and that picture of the first start up, I could smell to 2smoke!

jasonu

1st January 2014, 14:01

big day yesterday getting the bike relicensed and legal,it was a good sign when getting to the ltnz station and having the techo's practically tripping over themselves to get her off the trailer.i even had a good old chat with a random guy who followed me halfway across town to get a closer look as he used to own an lc way back as well.turns out he still owns a black and yellow tdr250 that he is putting back on the road.

She flew through the licensing no worries with no yet to do's on the list...sweet give me my license plate i'm out of here.
Today was spent just riding and 200 odd k's later i'm satisfied she's run-in.
Final jetting has still got to be sorted as there's still a niggly flat spot between 5-5500 revs...but it's nothing a quick two gear downchange doesn't fix:cool:

A few pic's between smoke breaks...

i like it!!!!!

Mike.Gayner

4th January 2014, 09:56

Amazing work eel, looks bloody fantastic. Hoping to get my A7 legal in the next week or two.

Russell Fleming

18th August 2015, 20:28

I have been looking for a 350LC for the last ten years-I finally found about 2/3 of one in a pile of Yam bits last year-have been steadily gathering the missing bits-Cant wait to actually ride the thing-I put mine through a gorse hedge at 130kmh in '89 then some arse set fire to it.. Hey ho-still looking for several bits-the plastic parts are as hard to find as rocking horse shite-the guy on the U.K yamaha site was right!! They could literally cruise at 145kmh, real smooth, nice peaky power... I haven't even seen one for about ten years-great bike good on ya!!

J.A.W.

27th August 2015, 18:25

GrayWolf

30th August 2015, 01:45

E-R, good effort.. I've had a bit of fun with them over the decades..

See if you can find an XJ 550 back wheel..
..its wider @ 2.15in, but will fit with a bit of basic work, & still looks original..

Big Kawasaki triple mills fit pretty easily too, FYI..
& do markedly improve the steering/roadholding - as well as the obvious..

Yes they do, a yamaha mechanic in the UK Nick Shaw who worked in Wallington M'c's put a 500 triple in an LC frame, there was also a couple of RD 400's shoved into them, as well as 'reversed' 350 lc dropped in RD frames...
However I can assure you from owning a 350 LC, {stan steven's road/club tuning} it was way quicker than a 500 kwaka triple powered one. I replaced a H1a I owned with the LC, as it didnt require an underpants change at every corner......

husaberg

30th August 2015, 01:50

J.A.W.

30th August 2015, 08:50

Yes they do, a yamaha mechanic in the UK Nick Shaw who worked in Wallington M'c's put a 500 triple in an LC frame, there was also a couple of RD 400's shoved into them, as well as 'reversed' 350 lc dropped in RD frames...
However I can assure you from owning a 350 LC, {stan steven's road/club tuning} it was way quicker than a 500 kwaka triple powered one. I replaced a H1a I owned with the LC, as it didnt require an underpants change at every corner......

I've had heaps of 'em since back in the day when they were just cheap ex-racer stuff..

I 1st stuck a 750 triple in an LC 'bout 20 years ago ( still have it) because I had them laying about & it was an easy do.

These days it is regarded as a criminal waste of 2 valuable classics! Hah.. bullshit..
& I still run an RZ 350 as a bloody commuter..

As for the 500 triple, I 've owned/operated most of the variants.. the eariler - the quicker they are in stock form..
..but its not difficult to make 'em all run harder.. ..as stock, a good`69 H1 will speed-wise whip any RD 350 Yam earlier than an RZ..

See here, 12.8 @ 99mph 1/4 mile, & 125mph top end speed.. http://www.kawtriple.com/mraxl/reviews/69h1pg7.htm

One RD LC 350 I owned was an ex-production racer which had various 'naughty' components ( inc TZ rods),
& it was a quick one, but still no match (in a straight line) for a similarly tricked-up triple..

husaberg

31st August 2015, 15:16

RD café Sleeper RZ motor FZR disk.
315332

Oh a Rd powered By an H1
315336

J.A.W.

31st August 2015, 15:37

Yeah, thanks H, & while those YPVS mills feel a bit tame by comparison to earlier ( peaky pick-up) RDs, they do go..
..plus, if you ride around keeping those YPVS 'economy valves' shut ( up to ~5,500rpm/115 k/mh in top) they'll
bloody well do 55mpg too..

F5 Dave

31st August 2015, 22:06

Never understand why people like peakier bikes over the RZ. But if you did all you need to do is pull the fuse out in the open position.

T.W.R

31st August 2015, 22:50

The H2 fits in as well.
I have a pic of one somewhere with a Xj rear wheel and H2 Kawaka 750 powed LC it looks like a great stealth bike.

Issue 31 Streetbike 1st bike in readers rides :msn-wink:
Wasn't exactly straight forward repower & the xj550 wheel was awkward. 50kg lighter than a std H2 & double the power the 350lc etc.

husaberg

31st August 2015, 23:22

T.W.R

31st August 2015, 23:45

It was also the Guy posting here have a look at the owners name and figure it out, Ya miles behind.

:lol: you're the one who said you had pic of one....... You obviously didn't make the conection till you saw the name either :rolleyes:
More a fan of the bloke in UK who slotting RG500 mills into RGVs. :2thumbsup

husaberg

1st September 2015, 00:26

:lol: you're the one who said you had pic of one....... You obviously didn't make the conection till you saw the name either :rolleyes:
More a fan of the bloke in UK who slotting RG500 mills into RGVs. :2thumbsup
Like I said days ago
There is plenty of those I can remember about twenty of them

My fav one was one NWS did or the one with all the Real swantze and harris stuff

J.A.W.

1st September 2015, 09:09

Issue 31 Streetbike 1st bike in readers rides :msn-wink:
Wasn't exactly straight forward repower & the xj550 wheel was awkward. 50kg lighter than a std H2 & double the power the 350lc etc.

It is a remarkably straightforward operation to adapt the Kaw mill to Yam chassis, & the XJ wheel mod is likewise not moon rocket stuff..

The extra power from more than doubling the capacity is expected, but the improved steering/handling/roadholding is a bonus..

The larger Kaw mill means the 'flighty' light feel at the front end of the RD, that makes nervous people want to fit a steering damper, is gone..

roogazza

1st September 2015, 11:20

you got some pics of the H2 / RD ????? Be interesting.

J.A.W.

1st September 2015, 11:40

Email me, & I'll send you a couple..

husaberg

1st September 2015, 11:47

Email me, & I'll send you a couple..

Do you want me to post them for you.

J.A.W.

1st September 2015, 12:08

If you'd be so kind H, sure, cheers..

husaberg

1st September 2015, 12:30

No worries.
You should be able to do it soon.
315361315362315369

J.A.W.

1st September 2015, 19:01

Yeah, ta H, I put that heap on a weigh bridge.. 160kg drippin'.. with all the road legal shit you see there, on board..
Dunno if its the gyro forces from the big triple crank that settles the 'flighty' feeling RD high speed steering down,
but, for sure, its a significant improvement for ~15kg worth of extra mill weight..

GrayWolf

2nd September 2015, 02:09

I've had heaps of 'em since back in the day when they were just cheap ex-racer stuff..

I 1st stuck a 750 triple in an LC 'bout 20 years ago ( still have it) because I had them laying about & it was an easy do.

These days it is regarded as a criminal waste of 2 valuable classics! Hah.. bullshit..
& I still run an RZ 350 as a bloody commuter..

As for the 500 triple, I 've owned/operated most of the variants.. the eariler - the quicker they are in stock form..
..but its not difficult to make 'em all run harder.. ..as stock, a good`69 H1 will speed-wise whip any RD 350 Yam earlier than an RZ..

See here, 12.8 @ 99mph 1/4 mile, & 125mph top end speed.. http://www.kawtriple.com/mraxl/reviews/69h1pg7.htm

One RD LC 350 I owned was an ex-production racer which had various 'naughty' components ( inc TZ rods),
& it was a quick one, but still no match (in a straight line) for a similarly tricked-up triple..

\ yes I agree, i had an H1a {UK variant with the 'coil' ignition} was only slightly slower than the mach3, and agreed quicker than a 350LC, but as I said my 350LC was a stephen's {the yam guru} tuned one.... and it was quicker than the kwaka, in fact in the early years of LC production, there were two 'club' tuned?? stephen's 350LC's at boxhill surrey and they took immense delight in chasing/beating CB900's. CBX's. Kwak 1000's round the 'circuit' and were incredibly quick on acceleration.

roogazza

2nd September 2015, 08:52

No worries.
You should be able to do it soon.
315361315362315369

Ta , never seen one of those ! Must be a great with the H2 torque ? From memory the stock H2 was finished at 7500rpm .

J.A.W.

2nd September 2015, 09:08

Ta , never seen one of those ! Must be a great with the H2 torque ? From memory the stock H2 was finished at 7500rpm .

Yeah, stock H2 is really a bit of a 'Clark Kent' in standard form, soft-tuned from the factory, but like most 2-strokes a bit of tuning
wakes 'em up nicely.. if you check the dyno charts in the 1973 Superbike Shootout thread elsewhere in the classic section, you'll see..

roogazza

2nd September 2015, 12:33

Yeah, stock H2 is really a bit of a 'Clark Kent' in standard form, soft-tuned from the factory, but like most 2-strokes a bit of tuning
wakes 'em up nicely.. if you check the dyno charts in the 1973 Superbike Shootout thread elsewhere in the classic section, you'll see..
Yeah I have a mate who had one same as mine, the first blue model.
But when I rode his, he had another 1000rpm to make it 8500rpm !!!!
" Production" don't you know !!! haha. :msn-wink:
He won on it as I remember at Gracefield Wgton but sold it shortly after (probably before the protests started ??? lol)
But yes stronger down low than the CB750 Honda of the time.