What did you do to your Yamaha today?

I was going home from work a few years back, and, after being passed by several sports bikes on my 1150GS, I realised it was biker night in Whitby (Dracula not Ontario)
I kept a few behind me on a twisty uphill dual cabbageway, but the GSXR that flew past on the final straight didn`t know about the car park exit at the top (blind brow). He T Boned a fiesta just before I got there. He was conscious and breathing (just about), his race leathers were all that was holding him together, and the air ambulance was called.
I kinda went off racing after that.

 

A little maturity goes a long way.

 

You may be interested in the valley in the torque from 4-7K from a Cycle Guide article, June 1981.

 

That is a VERY interesting piece of the puzzle and I thank you for sharing it. I'm curious as to what is causing or contributing to this "torque valley" in the XJ being it's right in the middle of the highway operating band. From the little I've gathered with the camera it appears to be a function of the needle taper coming up to the shoulder of the needle body itself where the taper becomes more aggressive and I'm tempted to locate a set of "police" needles to confirm this.
What I did do was take my 750 SECA for a good interstate run Monday afternoon after swapping in the modified aftermarket emulsion tubes on the #122 mains to see how things panned out. The original plan of mixed city/highway riding got nixed so I took the opportunity to really run the bike. Unfortunately that torque valley really shows itself on the interstate from about 65 to 80 and twisting beyond the 1/2 throttle gets almost nothing, I had to drop down a gear several times just to make passes one time reaching the century mark and this is when the bike felt really good. The downside to all this is the lack of MPGs and the best I could muster under this was 28. Honestly I don't know if this is better or worse being the bike was designed & tuned during the Reagan admin for emissions and the prevailing 55 MPH limits so I'm curious as to what others are experiencing with their 750 XJ's. I suppose I could get high 40's to low 50's running at 55-60 MPH at the risk of being flattened by some overbearing SUV. According to an older Cycle World article from June of '81 this is about what they found during their tests.
In retrospect it's no worse than some of my past machines be it the 1980 CBX I wrecked or V45 Magna as they too were tuned under the Reagan administration, the CBX was an excellent cruiser and had many camping trips on the book while the V45 was a commuter with a nervous disposition and really difficult to get at carburetors. Maybe I need to keep my expectations in check after all the SECA sounds like an angry b*tch above the 7000 mark and will happily go beyond the 9500 mark passing another sport bike. In short it's fun and maybe that's what I should focus on.

Now down to the emulsion tubes the motor had a slightly better feel off the line, streetable best describes this but get into that torque funk it's almost as bad as the stock pieces with the OE #120 mains but without the breakup. I may make a few more mods to both the tubes and swapping around the jets but seeing what that article says I'm not sure how much more is going to help short of fuel injection or going with a different carburetor. Swapping in my #126 mains this early wednesday and changing the oil, weather guesser is threatening us with breezy warm temps so maybe I can get a few miles on the saddle and see how this works out. If nothing else I can piss off my neighbors.

 

Couple of points to consider:

a) starting in the late 70's and then getting progressively more stringent into the 80's, emissions regs (expecially CO) were getting more restrictive and the manufacturer's response was to lean the engines out throughout the rpm range, but especially at idle and off-idle speeds. It got so bad that Yamaha actually issued a dealer bulletin that says (paraphrasing): "if a customer complains about poor off-idle performance (acceleration for normal street use), yank those mixture screw plugs out and richen up the pilot mixture screws a bit." So much for those EPA regs........

b) for street bikes, the most important bit of "performance" for a typical rider is the torque response at lower rpm's....in other words, off-idle to mid-range......the typiral "city driving" mode with a lot of stop-and-go riding. You don't want a bike that is sluggish at off-idle or mid-range, as this is frustrating for the typical owner (who then goes and adds pod filters to improve performance, or bigger jets and shims the needles, all of which tends to further decrease lower-rpms performance as those sort of changes move the torque and horsepower maps further up-and-to-the-right of the rpm curve.......).

So you can see the tug-of-war here: lean it out to meet emissions regs, and then figure out how to deal with the off-idle / mid-range performance issues that leaning it out creates (this problems still exists today, which is why almost all auto manufacturers do some type of "cheating" on emissions certification testing, and sometimes get caught).

In reality, a few simple changes to these era bikes will create a much better user experience, and this usually involves richening the pilot fuel circuit (larger jets and/or mixture screw position adjustments) and basically leaving the main fuel circuit alone (or increasing the jet size by 1 "size"). For wringing even more performance out of any given size engine, the choices are basically to move the torque/horsepower further up the rpm scale (which then makes it sluggish at off-idle and mid-range rpms), or, as the saying goes, there's no substitute for cubic inches (or millimeters, as the case may be).

All-in-all, for that era and for the target buyers, these bikes were a pretty good compromise for the typical owner.

 

You're right it's been quite the tug-of-war despite the compromises, unfortunately the tech wasn't there when the bike was made the last part of 1980 and I have to adjust my expectations accordingly. Right now I'm working on dropping my #126 mains back in and checking/wet-setting the floats, I have #42's on the pilot side and have them all balanced within one inch Hg on 2.5 turns of the fine thread needle. Around my small town and on the rural highways it's well mannered and quick with a crisp throttle so I'm thinking this is about as good as it gets. The #126 mains seem to work well with the 4-into-1 Kerker Pro Sport exhaust and our ethanol laced gasoline, going to dump a jug of 100LL AvGas in and see how that goes. Looking like thursday is going to be the day as I don't feel like bucking a 25 MPH head wind.

For that era... I was going into the 5th grade when this bike rolled down the assy line and soft rock dominated my radio. How things have changed.

 

I'm sorry, but I can't see Yamaha letting a bike go into production with a simple carb related issue giving that torque trough. Far more likely it's to do with the exhaust system they "had" to use, or this and a combination of this and lack of suitably mapped ignition. By mapped I mean one that can add advance, then retard at higher rpm, or more throttle to reduce pinking. You want to fix the trough - get a mappable ecu, four into one, and put the bike on the dyno - you might also need some jets and needles though.

 

I should add: given what the desired riding performance was supposed to be (from Yamaha's perspective and understanding of "the market"......who would be buying these bikes, what did they expect, what does our advertising promise and promote, etc.), the design of the engine system then follows from all of that ---- so it's not just the carb jetting that is taken into consideration, it's also things like: carb type and size (venturi diameter, etc.), cylinder head design, camshaft lift and timings, compression ratio, and as mentioned above, ignition timing "mapping", etc.

The point being, the carb jetting is just a small part of a bigger puzzle, but of course since the carb jetting (and air intake system) is one of the easiest thing(s) to monkey around with, that is where most of the effort goes (and with predictable results).

Or as Chief Brody said to Captain Quint in "Jaws": I think we're going to need a bigger bike.......

 

I can heartily recomend a Vmax, but then people further tune them.
The XJ900 must be worth a look too, given we are an XJ forum - same engine as the 650/750, stiffer frame (slightly longer, which is possibly a negative), looks good too. Not forgetting the XJturbo... But of course, we know someone turbo-ing a 900...

 

FWIW, Regan was in office less than a month when mine rolled off the line in February of '81. And I was celebrating my 7th birthday.

 

Well Raegan might have had something to do with covering over the idle mixture screws on US machines, but I would suggest nothing else, and certainly not elsewhere in the world.
I once had a mini (A series) engine on the dyno, I was setting the ign advance on a mapped system. Normally you limit full throttle ignition timing to around 32 degrees. At 4000 ish (I could check, I would still have copies of the map), I added timing, in 2 degree steps, more and more, up and up went the torque. In the end I had 42 degrees of timing in there! I had to back it off to saner levels due to the load sites either side needing less, but it was an eye opener.

 

Mine is a late Carter bike, having been built in May of 1980.

Yesterday I (finally!) finished the muffler replacement. I ran into a string of annoying problems: on Monday, my cheap "titanium coated" drill bits burned themselves into oblivion drilling 10mm holes in the mild steel stock I had bought to make brackets, and my attempt to just push it through led to the drill burning out. Sigh. Yesterday I borrowed a drill and bit set from a friend, then got sidetracked by the fact that the right muffler (the one that will have to come off at every tire change) had practically welded itself to the adapter I put on the collector outlet. Much measuring and fiddling and trimming followed, and I finally figured out the Harley Sportster muff's inlet narrows down a bit just back of the slotted clamping portion. I solved this by putting a "go no further" mark on the pipe and cutting the hanger bracket accordingly.

Fiddling and trimming the adapters on the collector gave me the opportunity to pull the system off and re-install with nice new gaskets. I did not replace the head pipes with the spares I found in the box o' parts, because while they were shinier than the originals they were also more beat-up. I probably should have wire-wheeled the rust off the originals and then painted them with high-temp paint, but that's a project for another winter. Summer's just about here and it's time to wrap up the wrenching season and get into riding (though I still have to install the "performance" cam in the Himalayan).

Getting things lined up was tricky. When I first put the mufflers on the ends of the pipes, the welded-on mounting tabs (which were perpendicular to the surface of the muffler) aligned with the middle of the muffler/passenger-peg mount casting. Hmm. I rotated the mufflers until the bend in the mounting tab lined up with the back of the muffler hanger rubber (green line in the photo). This had the tab sticking up at about a one o'clock position (red lines) as seen from behind. A little quality time with vise and hammer fixed that, leaving the tab in the correct vertical orientation:



On to hanger fabrication, which involved some CAD tools:


"CAD" standing for "Cardboard Aided Design"

And a little trial and error:


Notch required to clear passenger peg bolt. No idea why it's only needed on the right side.

And, of course, a bit of persuasion to match the alignment of the hanger bolt (straight east-west) with that of the muffler (splayed out a bit).


Always important to note which side gets hit.

Everything lined up, mufflers slipped into position, clamps tightened, everything felt solid. Roll the bike outside, start the engine, got a nice smooth purr punctuated by a loud pop-pop-pop that seemed to be coming from the front of the bike. Yeah... I had tightened the headpipe-to-head nuts on cylinders 2, 3, and 4, but cylinder 1's nuts were still finger tight. Oops. Quick tightening, and the bike sounded good. A little quieter than with the original pipes, but not as much as I had expected.

Took the bike for a ~70-mile ride, hit some bumpy gravel roads, checked tightness when I got home. All good. The bike sounded pretty much the same as with the original rusted-out pipes, perhaps a bit quieter. It also seemed to run a bit better, with less of a flat spot around 6000 rpm. I suspect the rusted-out mufflers were a little less restrictive than this already-lean engine wanted, and a bit of back pressure made it run better. The "butt dyno" also suggests a bit more low-end grunt than before (again, to be expected from a bit more back pressure).

I neglected to take a photo of the bike with the new mufflers (too busy enjoying riding it), but will post one after my next ride. All in all I am pretty happy with the results of this project. All that remains is to decide whether to have the hanger brackets I made welded to the mufflers, or leave them bolted in place. And install some kind of rubber baby-buggy bumpers where the centerstand and side stand hit the mufflers.

I am still debating whether to take the Maxim on the Hügellandschaft Adventure Ride (two days of gravel and dirt roads around Galena, IL) next weekend. I think it's more than up to the job (after all, I did put "dual-sport/ADV" tires on it), but I still need to install a mounting and power supply for the navigation system if I'm doing that. The alternative is my Himalayan... but if I take that bike, I will need to install the "performance" camshaft that bumps it from 24.5 to about 28 horsepower ("performance" is relative). Decisions, decisions...

 

As promised... a couple photos of the new mufflers on the bike:



The Harley parts are now the shiniest things on the bike!



I was out having fun on pavement-free roads this afternoon, getting ready for the Hügellandschaft Adventure Ride next weekend, when I spotted major leakage around the right fork seal. Nuts. My temporary repair was a little more temporary than I had hoped. Well, it got me to the Crud Run. I have a replacement set of forks, but they are going to require a bit of assembly and installation work, and at this point I have run out of time. So, next year. I hadn't yet figured out how to mount and power my navigation system either, nor do I have the slightest idea how to load my heavy camping kit on this bike, so probably a good idea to wait anyway.

But boy, those mufflers look cool!

 

Dude they DO look cool and if I didn't know any better (being I'm not the brightest bulb) I'd say they were stock.

NAV system mounting; maybe what I have going will help with the ideas. I run an older Garmin Nuvi 1450 in a RAM cradle mounted where the YAMAHA filler used to be, the mounting holes were the exact distance as the head and I used some spacers to jack it up. Power comes from a bucking regulator board avail from Amazon and it's set to 5.1V output powered by ignition on. I normally use the Garmin for a speedometer but the breadcrumbs have helped a time or two. Only drawback to all this is the mount obscures the key some, where I'm at it's not a problem but the key comes out when I'm in the city.
Going to blast and VHT paint my exhaust this weekend if the weather cooperates.

 

I have a standard RAM ball mounted in the same place. It’s convenient for sure.

 

They do, just like they belong there.

 

Spent the weekend blasting & painting my pipes and muffler, went with a silicone based high-temp paint that's used on injection press barrels. Got four layers down.


Yes I did, earplugs in and 25 miles around the loop with several times beyond 9000 RPM. Was never liked much by my neighbors.

 

So today I now have 3000 of my own miles on the SECA since it was resurrected, 39,021 miles on the clock right at the intersection of hwy 107 & Memory Ln by Ryders Saloon in Henriette... couldn't have planned this one better myself.

 

Perfecto. Reminded me I'm getting close to a milestone as well. Sitting at work, I'm 49 miles away from 40k. Ride home is 26. Hope I remember to watch for the roll-over on the following ride.

Got the bike in 1995 with 11.5k miles on it. Average annual mileage is really distorted due to about 15 total years of downtime out of that 29 years.

 

Didn't have my phone with to snap a couple of pix, I will when I reach that 10,000 mile point however. Today it's all about adding to that bug collection on the headlights!

 

Okay so I added some bugs to the lenses and dust to the underside... this brings me to a question of what is the best way to repaint the black part of the rims without making a mess of the bright aluminum? I really don't want to make a mess of this but the castings are really showing their age.

Thanks in advance.
Brhat

 

Does the machined aluminum parts still have clear on them? That often starts to look yellow and crusty and needs to be removed before you start painting, in my opinion.

Then it’s just a bunch of tedious masking.

 

Clear is long gone, confirmed this with an ohmmeter... not looking forward to the masking

I see you're from Mpls, might have to get together and check out bikes

 

Was pulling things apart to change stem bearings in the 650 and found this creative bit of wiring. The kill switch has been turned into a headlight OFF switch with some cross connected wire nuts. I guess the PO really didn't like having the headlight on. Gotta say, it works though!

Didn't really notice before because I never use the kill switch on any of my bikes, just the key switch. Yah, probably a bad habit. I have many.

 

No fixing stupid that's for sure.

 

I used an artist's brush and applied a layer of soap on the unpainted ally bits, before hitting the black bits with a spraycan. It worked better than I hoped, after curing and washing.

 

Rolled past 40k miles on the way home from work this morning (speedo runs about 4 miles less than GPS on a 26 mile commute).

 

Yeah man that's what I'm talkin' about, an XJ owner with a big s*it eatin' grin on his face under the bucket on his pride & joy. I say this because I did a marathon trip today having nothing better to do and all day to do it.

 

We should organize a get together. Any ideas for a venue?

 

Good question. I know the cities quite well having lived and worked there over the years, maybe something like the falls or one of the lakes? I assume we would want to keep this one family friendly and I'd be good with something inclusive of both cities at a common point.

 

Looking at pulling my swingarm out and doing a blast & prime/paint along with checking the bushings and driveshaft U-joint. Unfortunately I ran over a wild turkey (bad timing) and now the bike feels a little squirrelly so I'm going to check things over, I did some hard quick jockeying trying to miss the bird and almost wiped out and now the back feels loose. Wheel bearings seem good but under hard throttle the bike doesn't feel like like it's running straight & true and it's not consistent between the shifts like the back end is pivoting from loading to unload. Should be an adventure.

 

When for a fantastic ride! The xj650lj clicked over 10000 miles on the way home...

 

Update on my 750 SECA.

Pulled the rear apart this evening and found the bearing preload locking nut loose and the adjusting screw had backed itself out over time giving me roughly a 1/4 inch of total play, I had never really pushed the bike before the bird incident so I never noticed the excess play until then... just one of those things I guess. I've blasted the paint off and checked all the welds and they look good, some minor pitting from previous battery pukes so it's going to get scrubbed with some 320 on the DA then a good prime & paint before going back together.
The locking tab on the LH side doesn't look like it's ever been disturbed since it was installed so my question is: how much assembly is done at the dealership when the bike comes out of the crate? Personally I can't see the swingarm being something the dealer would install as it's tucked under the frame and nothing is gained packing it separate and even so the dealership it was bought from, W.I.W. had a stellar reputation.
Engine & electrical problems I can deal with as they come up but when it comes to suspension, steering and safety related that's when I get concerned. Starting to wonder what other surprises are lurking from deep within.

 

From my brief time working in a dealer and PDI-ing various Hondas, etc. The front wheel is usually off and stowed next to the forks, the bars might be un-affixed and laid lengthwise.
Usually, the rear wheel was on and only needed the bolts checked for tightness, along with all the others. It was a fairly minimal strip for crating, just enough to keep within the crate dimensions.

 

Sounds about right, guess the adjustment never had a final torque or had worked itself loose over the past 40+ years. The races don't look distressed so they're all going back together tonight once the paint hardens. I used an industrial type medium gloss that sets with heat so I made a rack for my drier. Yes my arm is swingin' !

 

Your swingarm is getting an MRI! Note: hope you didn't get too much paint where the races are fitted, or, you'll be scraping paint away from those areas tomorrow.........

 

It also got a cat scan before assembly and the only thing that got me cussin' was getting the splines into the U-joint while it was flopping around. The U-joint is good with no play at all and the bearing races & pockets got a good cleaning with acetone before the grease. Everything went together well and I took the bike on a 25 mile shakedown ride, straight & true it rides like an easy chair with a twist grip. The plan this weekend is to finish the fuel system on my buddy's VTX-1800 and take a ride up to the north shore via the back roads, plenty of good curves along the way.

Okay so he was sleeping on the job again...

 

Got my mitts on some paint today and made a few swatches on a chunk of steel according to the paint mix directions. Going with a DuPont light toreador red which has a slight metallic iridescent mix, not exactly the factory brilliant red but not $199 for a pint either. This is a 3-part HVLP solvent mix that will work good on the side panels over the existing paint and being I already have most of what I need already it saves me some serious coin.
This is the swatch of the actual finished color against the lower part of the tank, a smartphone camera doesn't do it justice. I also have a shade lighter that I will swatch tomorrow when the light is better but I'm thinking this is the color I'm going with.

 

Tried to do an edit and ended up with a new post... Any ideas on how to blow this dent out without making a big production of it? The smaller dents will get lead filled but this guy needs more finesse than I have.

 

Decided to try vinyl wrapping my gas tank emblem. Looks good from far away but the cuts up close aren't clean and the previous owner's spray can paint job has an uneven surface.

 

Dude that's a good 20/20, 20 feet away at 20 MPH it looks great. I'm going to do the Yamaha tuning forks stencil but I'm still on the fence if I should do them on the tank or the side covers.

 

See if a PDR guy would try it??

 

I painted a tank! Ok, ok...it ain't much, but this was my first true foray into the paint world. Normally it's some extra heavy coats of rattle can and carry on.

Still rattle can this time, but started at bare metal, bondo where needed, primer, sand, base coat and 2K clear coat. Lots of sanding, polishing and starting over along the way. Definitely a few flaws to pick out, but I'm happy with the result, and learned a new skill along the way.

My biggest hurdle to paint has always been fear of messing up, but once you figure out that almost any run, drip, orange peel or defect can be repaired, it's not so bad.

 

Not bad at all, looks really good.

 

That looks super great for rattle can, and very very good even if applied via air gun.

 

My buddy (the guy that gave me the yx600’s) rode his fzr600 today. Good from far, but far from good

 

Burning the midnight oil getting my Secas ready for the vintage rally this weekend.
I've been putting off fork seal replacement too long.
So long the sidecar forks contaminated the brake pads so now I'm waiting last minute for new pads on that one.
Just one leg leaking on the Turbo, I didn't renew the seals when I installed FZ600 forks during the build.
This one was a real bugger to get apart.
I discovered the crush washer missing on the damper retaining screw so this didn't help the removal.
I found a suitable crush washer on hand.
Took another chunk off the preload spacers as the front end was just a little stiff.

I ran low of 10W fork oil for the last leg.
FZ600 called for 315 ml.
I used 100 ml 20W + 100 ml 5W + 115 ml of 10W.
That should work out to 10W, am I correct?

Fork seal driver.
Did you know that standard 1-1/2" ABS pipe is the perfect size for driving in 36 mm XJ fork seals?
3' long piece at Home Depot for a few dollars.

 

Great info.

 

That's about what I used to do the seals on my 750 SECA. Just long enough to push the seals in place.

 

A few days delayed, but I had an interesting experience on Sunday. The woman who organizes a long distance bicycle ride I've done/failed the last 3 years asked for my help with a triathlon she was putting on. For the cycling segment, I carried a race official as pillion and we rode the course twice watching out for illegal drafting. Didn't have to bust anyone, but it was cool being on 'that side' of an event. Was also cool b/c the police controlling traffic must have gotten word we were official, because we got waved through a few red lights even when were weren't near a group of riders. Only about 30-45 minutes of 'work,' and a gorgeous morning, so a great excuse to be out for a ride. Was the official's first race and first time on a motorcycle. She seemed to have a good time as well.