Greetings from Mexico!

Hello from Mexico!
I'm the proud new owner of a 1981 Yamaha 750 Seca, that it is working well and even had the chain for locking it and the tool bag with a few tools.
Only thing I don't like: The front suspension seems too soft, spongy, if I pass a pothole it feels like the front tire is flat. Maybe I should change the front suspension?
Anyway, here it is, my $600 U.S. dollars baby:






It needs a good cleaning, has oxide everywhere, but it works perfectly.
Even the electronic sensors show everything in the control panel.







As I said, it even has the original "Power Lock" chain:







I will put it in better shape, while riding it.
Saludos desde Mexico!
macnifico

 

Lots of info here. Good luck.

You might want to check the air pressure in your front forks. There should be a tire valve on the upper fork tube. Use a manual tire pump and put some air in. I like to run mine at about 15 psi.

 

Mmmmh, no, I didn't find it...
But I'd really like to have a "stiffer" front suspension.
Is that the right term? Suspension?
Best regards.
macnifico

 

macnifco,

There's a decent chance I am wrong on this, but the tire valve on the upper fork tube is usually under a cap that is screwed on the top end of the fork. It should only be hand tighted and is frequently hard plastic. If you have the owner's manual the location will be shown in it. Otherwise, there are various ways to get an electronic version of the manuals for your bike at www.xjcd.org.

Also, have you checked to be you fork seals? They would affect the feel of the front suspension if they have failed.

By the way....welcome to the forum. There are a lot of XJ/SECA bike experts here (I'm not one) that have a wealth of knowledge.

 

Found them! There are two of them, one on each side, and they have a metal cover.
This is the right one without the metal cap.







And this is the left one, with me holding the metal cap.

I'm a complete neophyte at the art of maintaining and repairing motorcycles.
I'll get the manual so I'll know how to answer your question.

Thank you, and another thank you for your help.
Saludos desde Mexico!
macnifico

 

Hi macnifico, perhaps your forks are full of guackamoli, change the oil & you can get stronger springs, if you are a "rather large gentleman". Wiz.

 

Hi again!

As I wrote before, I just bought this bike, on November 18th, and I'm just discovering the thrill of a "real" motorcycle.
Last time I rode a bike was... mmmmh, 25 or so years ago.
I bought a scooter recently, a beauty; it is a Peugeot Vivacity with a small 100cc motor. I found it GREAT for the city, but I have to ride in a few parts that need a bit more speed, so I bought the Yamaha 750 Seca a few days ago.
I'm re-learning the shift-changes, and to control the power of this bike, compared to my scooter.
As I said, the bike has lots of rusted small spots (pits?) but almost everything works, including the control center, or computer, or whatever is called...
I don't know if the mileage is original (only 9,622 miles in 27 years?), if it already past 100,000 or if it was modified.
The trip odometer doesn't work, the odometer, speedometer and tachometer does.
The previous owner told me that it was left in an open field for years, before he put it in a barn and started it again. That explains the rust.
Here is a photo of what I call the Control Center:






Saludos desde Mexico!
macnifico

 

Yes, that could help. Old oil in the forks.
Plus, I'm 6' (1.84m) and 250 U.S. Pounds (115 Kg), so maybe it does matter.
And no, I'm not "rather large", I'm just a tad overweight. :lol:
Saludos desde Mexico!
macnifico

 

I'm wondering if your '81 is not an '82. The engine cover says 'YICS' and I thought that only showed up on '82 and later models... though I could be wrong on this. Also, does your bike have anti-dive valves on the front forks?

 

Well, the title says Year 81 Make YAM.
However, in the MFR'S IDENTIFICATION NO. it has two errors: It has a G where it should be a 6, and it has a B where it should be 8.
So maybe they got the year wrong, too.
And about your question...
I'm a newbie in this field, and I don't know what are the anti-dive valves.
I'm enclosing a photo of the front forks:






Maybe you can see the anti-dive valves... :?:
I will buy the Manual soon, I promise...
Saludos desde Mexico!
macnifico

 

I took a look at the Yamaha parts web site and it does appear that the '81 XJ750RH had YICS. And the dive valves are bolted to the bottom of the shock tubes. They have a connecting brake line that goes back up to the brake caliper. I'm sure someone here can tell you how they work.

 

either adding pressure, up to ~20psi max
OR
replacing the fork oil< theres a drain screw near the bottom of the "lower leg" of the fork
OR
upgrading to progressive springs
OR the best of all

DO ALL THREE

mine is pretty much the same, but progressives look to be in the near future

PS i would assume the oil has leaked out as the fork seals could be quite old.

ciao

 

So, I have to buy the fork oil seals, probably.
The oil is a special kind or readily available?
And the air, well; I can get it everywhere.
Saludos desde Mexico!
macnifico

 

I'll soon get the Manual. I promise.
Then I'll know what are the dive valves.
Thank you for your help.
Saludos desde Mexico!
macnifico

 

Macnifico, yes, your bike has the anti-dive system on it, that short (about 12-inches long) rubber brake hose WITH THE SPRING ARMOR around it is the hose that runs from the brake caliper down to the anti-dive valve assembly-----which is the rather large "protrusion" that is bolted onto the lower area of each fork tube (below the caliper, facing towards the rear of the bike).

Most people say they do not function very well, but they probably add a bit of stability for HARD braking actions, but they are very sensitive to low or dirty fork oil fluid, as well as needed rebuilding after a number of years (mostly the replacement of some rubber seals, etc.). The concept/theory behind them is that when you really squeeze firmly on the brake lever (during hard braking), the fluid pressure from the master cylinder will not only operate the brake caliper, but also----via that spring-armor covered lower fluid line---be transferred into a resistance "valve" at the bottom of the fork tubes, thus preventing or diminishing the "diving" action of the front forks.

Of course, you could always dis-able that system by simply not using that lower hose (fromt he caliper to the anit-dive unit), but you would need to use the shorter (single depth) brake hose union bolt at the caliper fitting (it currently uses a double-depth union bolt, since there are two lines attached at that one junction point).

Motorcycle fork oil is semi-specialized, and can be obtained at most motorcycle shops.

And yes, you really will need a service manual if you plan to service your bike yourself (or even, perhaps, if you take it to a shop in your country, which probably do not have the proper manual for this bike). The front forks a bit tricky to service properly on these models (primarily because of that anti-dive system).

I have all sorts of rebuild parts available for your bike, feel free to send me a private message (PM) and I'll be glad to help you out. And of course, I do ship to Mexico!

 

No need to ship to Mexico...
I live in the northeast of Mexico, justa across the border from Hidalgo and McAllen, Texas and about 65 miles to the East of Brownsville, Texas.
I do have a POBox in Hidalgo, Tx, and can receive UPS packages in McAllen, TX.
Thank you for your explanation, and yes, I'll get that Manual.
The mechanic where I take my scooter, and now my Yamaha, says he got one of this Yamaha's in the mid 80s, so he knows the model idiosyncrasies.
Saludos desde Mexico!
macnifico

 

Mmmmh, bad news.
The air in the forks leaks out in seconds.
So I guess I'll have to buy the seals, oil, and have the mechanic do the necessary procedures.
And probably will need new tires... :roll:
But even if I invest a thousand dollars on it, 8O , it will be cheaper than a new motorcycle.
Saludos desde Mexico
macnifico

 

Don't forget new o-rings for the air collars (the pieces that the air valves screw into on the forks). They can leak as well and are only a few dollars more to your total for fork seals. I would also suggest changing out your fork oil to a 15 weight and obtaining a set of Progressive suspension fork springs (a hair less than $100), but the spring change can wait.
Welcome to the fold!

 

First things first. I have to put the papers in order and get the title and plates.
Then I think I'll contact chacal to get an estimate of the necesary pieces.
Everything else seems to work fine.
Saludos desde Mexico!
macnifico

 

Congrats on the find!

Funny timing of it all is that I'm in the midst of planning a Mexico trip... I'm about 4700km from you. Sadly I won't be on an XJ for the trip, but my trusty cbr.

Anyhow - good luck with it! When I pass an XJ in Mexico I will give a big wave.

 

Thank you. I do think it was a great find!

Well, I'm in Mexico's north-east, near the Gulf of Mexico. I don't know if it is your route, but wave anyway.
Saludos desde Mexico!
macnifico

 

Yup - first trace has me aimed for Laredo texas or there abouts - maybe further east... from there? No idea - south and east... might try to go west to the pacific. No plans. Just want to see what I can see in only 10 days. I can't hang around too long as it takes me a solid 4 days to get back to my home.

 

Well, not to scare you, but you will be stopped, frequently, by soldiers checkpoints doing what is called "war on crime" but really is a suspension of individual rights. However, most of the time the tourists are not bothered.
Unfortunately, crooks often dress in soldiers or police uniforms, set out bogus checkpoints and kidnap or rob people.
And don't even try to get away from a checkpoint. Soldiers have shooted people that try to circumvent the checkpoint.
Here's a scan from my local newspaper that describes one such incident:






But as I said, this incidents are few and far in between, so just be careful and remember that most people in cars do not respect motorcyclist or their right of way.
Have fun!
Saludos desde Mexico!
macnifico

 

It's one of my issues... I'm not sure where to go, nor where to avoid. I've heard a number of people who made the trip and had a wonderful time. I've got at least 4 months to research.

I really just want to see Mexico... after that maybe a beach... I'm not really a tourist type

Right now I'm trying to figure out when would be best to go... I'm a cold weather person, so I figure I might have to go quite early in the spring to avoid the worst of the heat. I hear it is nice now, but it's too cold up here to leave now. 75-85 F would be perfect. This 100F+ stuff is no good for me

 

Weather at this time of the year in Mexico depends, of course, where you are.
In my part of the country, what for the Americans would be deep south east Texas, weather is perfect right now. Today we went as high as 82ºF and in the 40s at night.
But at Central Mexico, parts are in the 30s in the day, and below freezing at night.
In Southern Mexico is the rainy season, and is still hot. And of course, there are the beaches...
What I'm trying to say is that Mexico is a big country with lots of cities at different altitudes. As you know, at a higher altitude, the climate is more temperate.
Anyway, my favorite cities in Mexico are Guadalajara, Queretaro, Guanajuato and San Miguel de Allende. They are all in Central Mexico, and relatively close to each other. You can't go wrong in visiting any of them.
I can't recommend beaches. I don't like them.
And about the crime, well... We live here, and we are still alive...
so you too will return to your country alive and kickin'.
Just be extra careful, and have fun.
Saludos desde Mexico!
macnifico

 

I like that, San Miguel de Slurp.

 

Well certainly your Seca will look macnifico after some polishing up the metal with some different sizes of wire brush, on a drill and dremil tool. And the paint buffed and polished too. I insist on having a windshield too,
I got a bike like yours this fall, and it is a screamer.
Enjoy!

 

A windshield and a rack for my GIVI Flow E350N would be great.
Or a sissy bar and some way to put the groceries there.
This will be a "use-everyday" motorcycle.
And it will be "a project". To put it as close as "new-from-the-factory" as I can.



Here is my scooter with the GIVI Flow E350N. It will be on the Yamaha 750 Seca as soon as I can get a rack.






Saludos desde Mexico!
macnifico

 

A funny thing happened today to my Seca.
I took it to the mechanic to fix the switch that makes the rear brake lights go on when you brake.
Everything went smoothly, and now when I brake, the people behind me can see that I'm braking.
But when I was ready to leave, I noticed that the main front light didn't light up.
It seems that another switch went belly up.
No big deal, as I don't use the bike at night.
However, I like the other vehicles in the road to see me.
I'll check the fuse tomorrow. And anything else that I can think about.
Oh, the Yamaha Repair Manual should arrive shortly.
Saludos desde Mexico!
macnifico

 

Hi macnifico, have you upgraded your fuse board to the blade type?

 

Not yet, it still has the original one. With old style glass fuses.
Saludos desde Mexico!
macnifico