'81-'82 RD350LCs upgrades. Canadian.

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hondaror
Posts: 2828
Joined: Mon Mar 03, 2014 8:44 pm
Location: Alberta, Canada

'81-'82 RD350LCs upgrades. Canadian.

#1 Post by hondaror » Sun Mar 09, 2014 11:39 pm

I used to run the first gen LCs. Great upgrades include, RZ350 carbs and petcock with RD jetting. I ran this set-up for a # of years. TZ250 F or G clutch springs. I went through 2 sets of stock springs, and surprisingly no plates. After I put my TZ springs in, no more slipping problems. My clutch was still original, less the springs, at over 100,000 kms. I used to drag race guys Friday nights, with multiple launches very regularly.
RZ350 exhaust gaskets. Never have to replace those crappy RD crush gaskets again.
I used to run 1000ccs of tranny fluid, not 1500cc. Greatly reduces gear drag, and that bullit proof tranny withstands it.
Other than those mods, DG pipes and K&N filters. Spot on jetting. A modified Harris full fairing. Clip ons. No rear subframe with a replica TZ seat kit. No centre stand, ever. I even cut off the side stand and used to lean the bike on walls. The bike was fast, much lighter, lower centre of gravity and extremely reliable. Top end rebuilds every 50,000 kms.
I will post pics of the old bike, asap. I have to find them.
Rory
2 1984 RZ350s
1985 RZ350
9 1986-1990 RZ350s
2000 ST2
2005 749
2005 749 with 999 engine

LC Cnd
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Location: Vancouver Is. Canada

Re: '81-'82 RD350LCs upgrades. Canadian.

#2 Post by LC Cnd » Fri Sep 14, 2018 9:17 pm

Every find those photos Rory? Be interested in what they looked like.

Hooligan
Posts: 1966
Joined: Mon Aug 20, 2012 1:37 am
Location: Calgary, Alberta

Re: '81-'82 RD350LCs upgrades. Canadian.

#3 Post by Hooligan » Sat Sep 15, 2018 7:52 pm

Bigger carbs are fine on a racebike that is always running at high RPM but they will seriously degrade the midrange on a street ridden bike as air velocity through the larger carb bores won't be sufficient for good fueling.

I am running the larger single spigot petcock with a splitter. This is mostly to make it easier to install and use a quick disconnect fuel line fitting.

I haven't had any issues with the LC clutches but the clutch in our RZ drives me a bit batty.

For sure the later style copper exhaust gaskets are much better. IIRC I also run them with a paper type gasket between the head and the pipe flange? I'd have to go look to confirm that.

One mod that seems to be overlooked by most people but to me is a MUST, is a set of 6mm reed block spacers. This simple and inexpensive mod virtually eliminates the 6000 rpm hole in the power curve. The downsides being that fitting and removing the carbs from the stock airbox is a GIGANTIC PIA when there is 6mm less room between the airbox and the reed block. To eliminate the possibility of reed block air leaks I use an extra paper gasket and cover the gaskets w a spray gasket product. Works like a charm.

After several years of fighting with the carbs every time I wanted to remove or install them I had had enough and yanked the airbox. It got replaced by a set of dual stage full foam UNI filters. Now, removing the carbs is a quick and simple task, which immeasurably improved my life.

I am running stock pipes but with the higher flow "loud" baffles. Until I find the $1k for a nice set of expansion chambers, this setup is a nice compromise between stock and modified. I also have a fast response EGT system installed into the pipes. Its nice to be able to monitor what the motor is doing at all times. I figure if it saves me melting the motor just once it will have paid for itself.

Chassis wise, the first thing I changed was to junk the entire front brake system and install a set of Blue Spot calipers, steel lines and a modern master that resembles the original one.

We run Conti Classic Attack radial tires and these are lightyears ahead of bias plies.

Suspension wise I've got a Nitron shock in the rear and a set of 83 RZ forks up front. It all looks more or less stock but works a lot better.
'82 RD350LC in '81 colours, OEM pipes, UNI filters
'85 FZ750

Hooligan
Posts: 1966
Joined: Mon Aug 20, 2012 1:37 am
Location: Calgary, Alberta

Re: '81-'82 RD350LCs upgrades. Canadian.

#4 Post by Hooligan » Sat Sep 15, 2018 8:05 pm

Smaller things that are not stock on my bike are:

Bars: The OEM LC bars have an awful bend to them and are way too high. Lower and flatter bars feel way better and create a slightly more aggressive front weight bias, which the LC needs as it has way too much weight on the rear tire.

Grips and adjustable levers. Mostly stuff from eBay that was inexpensive and looks better than the OEM parts.

Mirrors: I kept a set of sexy and expensive Aprilia mirrors from another bike and they look and work great on the LC

Stainless Steel Bolts: Norbo's SS head bolts make the engine look so much nicer. The bike has a sprinkling of SS bolts where the fasteners are visible. Rearsets, pass pegs etc.

Balance Pipe: An artist friend made a beautiful custom aluminum hexagonal boost bottle for me. Its a one-off and sexy. Sadly its not very visible tucked in above the carbs.
'82 RD350LC in '81 colours, OEM pipes, UNI filters
'85 FZ750

Hooligan
Posts: 1966
Joined: Mon Aug 20, 2012 1:37 am
Location: Calgary, Alberta

Re: '81-'82 RD350LCs upgrades. Canadian.

#5 Post by Hooligan » Sat Sep 15, 2018 8:09 pm

And I nearly forgot. When I bought the bike from Solo2, he had spent the time to O-ring the top of the cylinders and set the squish properly at the same time.

This is a bit more involved of a mod but it is actually quite nice to have as it makes head removal easier and cheaper. A big pack of the O-rings can be purchased for about half the cost of an OEM head gasket.

As a result of the squish being sorted, the motor feels much crisper than the loosey goosey OEM setup.
'82 RD350LC in '81 colours, OEM pipes, UNI filters
'85 FZ750

hondaror
Posts: 2828
Joined: Mon Mar 03, 2014 8:44 pm
Location: Alberta, Canada

Re: '81-'82 RD350LCs upgrades. Canadian.

#6 Post by hondaror » Tue Sep 25, 2018 12:32 pm

Oh, no to larger carbs. I don't recommend that. RZ power jet carbs are great to run.
Rory
2 1984 RZ350s
1985 RZ350
9 1986-1990 RZ350s
2000 ST2
2005 749
2005 749 with 999 engine

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two-stroke-brit
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Location: Houston texas

Re: '81-'82 RD350LCs upgrades. Canadian.

#7 Post by two-stroke-brit » Tue Sep 25, 2018 2:08 pm

Rearset pegs ?
350LC,Athena 392 big bore,stock porting,swiss cheese air box,stock reeds,spec11 pipes.(now TSA big bore pipes)
She might not be pretty but she will always be a fun ride


1982 YAMA RD350LC
98KDX 220R
1967 TRIUMPH TIGER
2001 TRIUMPH TT600

Bare
Posts: 1196
Joined: Sun Jan 29, 2006 2:18 am
Location: vancouver

Re: '81-'82 RD350LCs upgrades. Canadian.

#8 Post by Bare » Thu Oct 11, 2018 2:08 pm

hondaror wrote:Oh, no to larger carbs. I don't recommend that. RZ power jet carbs are great to run.
Really!? A pair of 28mm PWKs is THE most /best first upgrade possible

evan_calgary
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Joined: Tue Nov 12, 2013 2:34 am

Re: '81-'82 RD350LCs upgrades. Canadian.

#9 Post by evan_calgary » Thu Oct 11, 2018 2:47 pm

Bare wrote:
hondaror wrote:Oh, no to larger carbs. I don't recommend that. RZ power jet carbs are great to run.
Really!? A pair of 28mm PWKs is THE most /best first upgrade possible
I would second Rory's no to this above.

Hooligan
Posts: 1966
Joined: Mon Aug 20, 2012 1:37 am
Location: Calgary, Alberta

Re: '81-'82 RD350LCs upgrades. Canadian.

#10 Post by Hooligan » Thu Oct 11, 2018 7:03 pm

Larger carbs will kill bottom end, which is exactly the opposite of what is wanted on a street bike. On a race bike I can see the bigger carbs for more top end but doesn't make sense on a street bike.

OEM carbs, reed spacers and properly sorted squish make my engine work fantastic. Very crisp and responsive.
'82 RD350LC in '81 colours, OEM pipes, UNI filters
'85 FZ750

Bare
Posts: 1196
Joined: Sun Jan 29, 2006 2:18 am
Location: vancouver

Re: '81-'82 RD350LCs upgrades. Canadian.

#11 Post by Bare » Thu Oct 18, 2018 1:56 pm

PWK 28's are NOT large carbs.
But then...what could the general Yama community (outside of Alta) know though?
Certainly a contrary opinion to ...anyone ....who has at least ridden a 350 fitted with PWK 28's.
PWK 28's give an amazing improvement in the low end and midrange power And throttling.

My pore 350 as small example :smt004 ..runs WOT from 3500 on to rev limiter without any bogging or even a single burble or missfire.
A straight linear pull. nicely impressive.
Complete proof is in the riding

Hooligan
Posts: 1966
Joined: Mon Aug 20, 2012 1:37 am
Location: Calgary, Alberta

Re: '81-'82 RD350LCs upgrades. Canadian.

#12 Post by Hooligan » Thu Oct 18, 2018 2:30 pm

Well ................ I am in the lower mainland. Maybe I just need to test ride your bike to see the proof in the pudding. :smt003
'82 RD350LC in '81 colours, OEM pipes, UNI filters
'85 FZ750

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Smoker
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Re: '81-'82 RD350LCs upgrades. Canadian.

#13 Post by Smoker » Sun Dec 23, 2018 2:20 pm

Hooligan wrote: Sat Sep 15, 2018 8:05 pmAn artist friend made a beautiful custom aluminum hexagonal boost bottle for me. Its a one-off and sexy. Sadly its not very visible tucked in above the carbs.
Any pics of the boost bottle?

Sounds cool!!

tacky1
Posts: 950
Joined: Wed May 13, 2015 1:11 am
Location: Pacifica,,

Re: '81-'82 RD350LCs upgrades. Canadian.

#14 Post by tacky1 » Sun Dec 23, 2018 7:59 pm

Bigger carbs dont do that much damage to the lower end, A little maybe, Ive run 34s on LCs and YPVS 350s and they didn't "kill" the bottom end, Granted the bikes lost a little lower, but not that much!!!!
Oh, And PWK28s are bounds and leaps ahead of the OEM carbs, Lower, mid and upper end...
1985 RZv500
1984 RZ500 Hybrid
1986 RG500 Walter Wolf
1986 RG500 Skoal Bandit
1984 RZ350
1984 RZ350 Hybrid
1981 RD350LC
1981 RD350LC Hybrid
2009 CR500AF Supermoto 250X
2007 CR500AF 250X
1988 YSR50 (2)
1984 GPZ750 Turbo
1989 VFR750R RC30

LC Cnd
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Re: '81-'82 RD350LCs upgrades. Canadian.

#15 Post by LC Cnd » Sun Jan 12, 2020 12:03 am

What about the idea of running one PWK 35mm into single pod filter? Heard its easier to tune & less expensive but just a potent. Found a new one for sale at a shop. Not sure what size of main jets to use a 34 with Micron exhausts however. Any susgestions? Love to get better exhausts but need to work with what I have apart from stock exhausts.

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