QUESTION FOR XJ650RJC (Canadian) Seca OWNERS:

Okay, so you've got one of those ultra-rare XJ650RJC Seca models WITH the YICS-headed engine..............

Now, I've got a question for you. Since you have a YICS head (like the other '82-up XJ650 and all XJ750 engines), does you bike use the '82 XJ650RJ intake manifolds (which are non-YICS heads) or does your engine use the YICS style head intake manifolds?

You can quickly tell them apart by observing the orientation of the upper and lower mounting holes of each intake #1 to #4, (in other words, left to right as you're sitting on the bike). Image a straight line drawn through the upper and lower intake manifold-to-head mounting bolts:

non-YICS, the intake manifolds are oriented like this:

\ \ \ \

YICS, the intake manifolds are oriented like this:

/ / \ \


Thanks!

 

Mine are like this: \\\\
why?
Since you're the identifier king, can you tell me how many of these "rare birds" were made? Mine is #741.
In other news?
Got any choke cables?
tks

 

Hey Wanna, thanks for the input.

So yours is a red bike? And is it a YICS engined model?

The non-YICS motors all had the \\\\ orientation, and they use different intake manifolds the YICS-engined bikes (supposedly).

I'd just like to know for sure what the 650 Seca YICS-equipped engines used, so I can be sure to offer/provide the correct ones to the people who need them!

As far as how many were made....wow, tough question. Unfortunately Yamaha never released (or, I've never been able to FIND) production figures for any of their bikes of this era.

Is yours a 15U or a 5V3 model?

Both of them started with serial number 100101, so in either case, yours is the 640th one made (which is almost the highest serial number that I've seen for either model). If you still have the paper tag with the VIN number on the steering tube, and don't mind sharing the build date of your bike, that would be a good piece of info, also.

Choke cables: I'm going to assume that the Canadian 650RJ and 650RJC models use the same choke cable as the USA model 650RJ bikes:

HCP2712 OEM original Choke Cable, for all XJ650 Seca and XJ750 Seca models.
$ 15.00


If not, then I'd have to get the original part number to determine what cable would be appropriate for that bike.

 

Hiya
Yep, mine is dk. red (going to stay red, just a flashier version soon)
It's the 15U. I'll look again for the build date and get back to you, though I think anything paper is long gone!
Yes, it's a YICS
Would the choke cable part number be this oem...299088-001 off of bike bandit for xj650rj?
Another quirky thing. My forks have the air valves (like the 750) would that have been a possible mod to my bike, or did they make the xj650rj with these types of forks???? Please pm me for the shipping and final price to K0H2T0 for the appropriate clutch cable. I might need a solenoid as well...click click click.
tks

 

Hey Wanna..........well, the problem with the 650RJC is that it's really tough to get info on. Some sources say that they're really Euro model XJ650's, with just a few "minor modifications" but don't always specify what those mods are.

Looking at the 1980, 1981, and 1982 XJ650 Euro parts diagrams gives no indication of an air-assisted fronk fork on those models, so unless someone else can chime in, that may be one of those dreaded, un-documented "previous-owner installed options".

The Euro models also do seem to use the standard 650 Seca choke cable:

HCP2712 OEM original Choke Cable, for all XJ650 Seca and XJ750 Seca models. NOTE: experimental testing has shown that this cable is an excellent reeplacement cable to use on XJ550 Seca models if you substitute "euro" or "clubman" style handlebars for the stock handlebars.
$ 15.00


Now, another question for you!:


a) Is your engine a 650 or a 750 engine? Rumor has it that some of the YICS-version XJ650RJC models actually came with the 750cc engine. You can verify the engine size by looking front and center at the top of the cylinder "jugs" (not the head) and the engine cc size is cast there. And you can verify whether the engine in the bike is original by looking at the flat, machined pad on the crankcase, just behind the clutch cover, and look at the hand-stamped engine code; if it's the original engine in the bike, it should read 15U-000741.


Thanks!

 

Well!
This just gets more interesting by the moment! The date stamp is 12/81 (that part of the paper is still on. Interesting, in that it was sold to me as a 750, and though none of the paperwork indicates how many ccs (the ownership just says XJC), the look of everything else is clearly 650 RJ (save the air forks). I will look at the engine stamp tomorrow!
FACINATING!
Now my parts list keeps getting longer, I'm sure to your liking;-)
Will forward more.

 

Well, a 15U model code IS for a XJ650RJC, it's just that some people say that some of the "later" (whatever that means) 650RJC models actually came from the factory with a 750 engine....even though Yamaha still called them "XJ650RJC" models.........

 

Apparently I also have an RJC model, somewhere along the line I was told it was just an RJ (wish I had known that when I bought the gasket kit - anybody looking for a head gasket for a non-YICS 650?)

The interesting thing is that I have the YICS head with the YICS intake manifolds i.e. // \\

My VIN is 15U-000652 stamped on both the engine and frame. and the cylinders indicate 653cc.

I know the engine was re-built at least once before I got it so there is a chance that it's not the original head... is there any way to tell?

 

Hey Jberg....thannks for the info.

Actually, the // \\ orientation of the intake manifolds IS correct for all YICS heads that I've ever seen.

I'm wondering if Wanna's head is an anomoly, or not really a YICS head? Wanna----does the head on your bike actually have the YICS passage (versus just saying "YICS" on the valve cover)?

As far as telling whether the head is original, there is no way that I know to determine that....they don't have serial numbers on them. After looking at a couple of heads, there appears to be a series of cast numbers on the head, one or some of which may be a production DATE CODE (date the head was pured/cast), and that could be a clue.....obviously, if the head was cast much, much earlier than the bike's build date, or, of course, if the head was cast AFTER the bike's build date, then something would be suspect.

Perhaps someone else could chime in on that issue, as I just don't know how to decipher those head casting numbers.

 

From what I've read here on the forums, I was under the impression that '82 was the first year for air assist on the XJ650RJ american.
I looked high and low for the nipple on mine and came to the conclusion that early on in its' life the bike had been wrecked and '81 forks had been put on.
There was a whole thread on it.
hhmmmm.

 

Sir Mr. Hound: I do not believe that the USA-issue XJ650RJ (5V2 models) used air assisted forks, either. The 1982-up XJ650 MAXIM models used the air forks (the 1980-81 models did not), so it may be those spirits that you are channelling.......

 

Thank you Mr. Chacal.
I must have misunderstood the post to mean the Seca's not the Maxims.
Gee, now I know why I couln't find those damn nipples, 1/2 hour I'll never get back.
:lol: :lol: :lol:
I haven't channeled any spirits since late saturday night, well early sunday morning.

 

Mmmmm. The Case of the Missing Nipples. Sounds like something for Sherlock Holmes to solve.

 

Hey there...Got enough gunk off to tell that, yah...it's a 748 cc engine. The crank case is stamped 51-2-100839. Just bought the gasket for an xj650rj as well. no workie huh? Will go back out and look at the YICS thang again.
Now what?

 

Ok...dummmdeedumm question: when "reading" the intake manifolds. I must be looking at them incorrectly. Trying to find a picture online of what you mean. It's the head coming from the engine to the carb connected with the rubber boots, no?
sorry (sooooooo new)
;-)

 

Here i am too, frame 15U-000693, YICS head and / / \ \ intake mainfold.

 

Hey Andreas, thanks for the update. Original engine (should also be stamped 15U-000693 on the frame case pad behind the clutch cover).....also, 650 or 750 engine?

 

Yes, the engine is the original one and the numbers on it matches the frame. According to the carving on the engine and the papers, is a 653 cc.

 

Thanks for the info!

 

Bumping a super old thread here, however I thought I would add to the guess on how many were sold in canada. My vin is 15U-000850. So at least 750 sold here.

 

Hi, first time here. I own a 1982 XJ 650 RJC which I bought in the Netherlands and turned into a caferacer some years ago.
The vin number is 15U000350 and is matching on frame and engine. It is the yics version and according to the papers it is a 653 cc.
The bike really runs well, but as for 2 weeks ago I noticed the cilinder head gasket is sweating, it is now time for a valve clearance adjustment plus gasket replacement. I contacted some internet web shops for a complete gasket set (cilinder head gasket, cilinder head cover gasket, base gasket and some other stuff) but they cannot really assure me they can deliver the appropriate set, since RJC stands for Canadian version.
Can anyone help me with this ? Part number ? Where to buy ...

I found following valve clearance specs which I thing are correct :
Intake (cold). 0,11 - 0,15 mm
Exhaust (cold) 0,16 - 0,20mm

Thanks,

Eddy

 

Contact Len at xj4ever or @chacal on the forum

 

those are the correct numbers

 

Hey all ... First post. Glad to finally be here. I just picked up an 82 XJ650RJC in near mint condition 15U-000321 /// \\\

 

Hi Chacal how do l know whether l have a YICS engine on my XJ 900 f thanks?

 

My XJ900 f inlet stub bolts are // \\ so is YICS Chacal.

 

YICS was an 81, to 86
YIKES!: ALL ABOUT THE "YICS" SYSTEM.
from above link

"YICS was used on:

* all XJ550 models
* all 1982-up XJ650 Maxim and Turbo models
* all XJ700 non-X models
* all XJ750 non-X models
* XJ900RK
* XJ1100 models."

 

Thanks XJ550 mine is a 1991 machine has YICS on the cam cover. Going to read the link now.

 

Is the XJ900RK the machine with the anti dive on the forks and the handlebar mounted fairing? My bike has YICS on the valve cover but no YICS stickers on the crankshaft end covers.

Good video showing the YICS ports and the before and after cleaning.

 

yes it is. the 83 xj900 seca. any crank end covers will fit someone probally broke the plastic originals and used the plain covers from the 650 non yics

XJ900RK

 

maybe the cam covers are interchangable

 

I was wondering what the differences in carburettor setup is between the XJ900RK and the XJ900f? I know from the write up the 650 had larger air jets on the YICS engine to lean the mixture in comparison to the non YICS engine. Is this the same on the XJ900RK engine?

 

Yes l think you are right l am sure I have a non YICS engine. It possibly is not the original valve cover.

 

My engine number mark on crankcase is *4BB-001114*

 

4BB00 = 1991 XJ900 Europe

 

Yes the registration document states the engine number is the same as the frame number but it is not so I am not sure if there is an error in the documentation or I have a different engine. Bike has had six PO's but I bought it because mechanically it was in great condition just needed a tidy up. I am putting it back together just now, there was surface corrosion on the frame so I stripped it all back to bare metal and painted it. I have rolling chassis now so I need to do some work on the engine now and get it back on the road.

 

I’ve never seen interchangeable covers between YICS and non- YICS

 

I am not sure hogfiddles to be honest my cam cover has YICS on it but the engine is too late to be YICS I think.

 

this is a 750 the bolt you see hnder the head on the cylinders is on both sides and is the yics port


this is supposed to be an 89 xj900 motor looks like a YICS port do not know

 

a 900F should be a YICS engine. However, most '85-later engines no longer have the YICS emblem on the round oil pump covers; they either say nothing at all, or, many of the 900 engines had an emblem (same size/shape as the YICS emblem) that said "DOHC".

 

I am going to get a small borescope and check as the photo XJ550H has of the 900f engine mine has the same bolt heads on both sides of the cylinders. My engine has DOHC where the YICS emblem is.

 

Hi again,

Gasket problem solved, but another question : I experience too stiff front suspension. There is no SAG at all when the bike stands on it’s own weight. I assume the previous owner did some modifications (aftermarket front springs) as I read everywhere that the OEM front suspension is too weak. Maybe there is a difference between a XJ650 maxim front fork and a seca fork ?

Can anyone measure the length of a standard 1982 XJ650RJC seca front fork spring ? I think a correct set of front springs will really improve the bike’s handling. For the rest the bike runs (and looks) great.

 

I see a lot of the DOHC emblems I think they are add ons from another bike or aftermarket as the YICS emblem is costly.

 

could be more oil than spec or heaveier wt than spec or used 10w30 motoroil

236cc, 7.98 oz of 10wt fork oil

5V2 82-83 factory service manual

540.5 mm spring length form haynes

spec from haynes is also for the 4K0 euro 650 so yours is likely the same

 

It is definately a YICS engine (I think all the 900's are) it has the four ports the o rings sit on. The emblem is costly I had a look for them.

 

Canadian RJC same as euro and Australia model without headlight on/off switch. Yamaha Canada figured we need the oil cooler because we have fewer months of great weather so we ride like hell in the time we have.
Pic is of spare engine.

 

Is it possible that a spacer has been installed on top of spring ?

 

Yesterday I opened one fork for inspection. I found a 3 cm spacer tube on top of the spring. Lucky for me. It gives me the chance to gradually cut it until the problem is solved.
Thanks for the feedback (also to chacal, who I accidentally contacted through the conversations section)

 

As for the initial thread question :
1982 XJ650RJC SECA
15U000350
YICS, intake manifolds orientation :

/ / \ \

 

I have same year and VIN is close. I have 15U000321