Re-re-reviving my '81 Seca 750

Tracked down possible a small leak at the pipe going into the distribution block. Not sure if that was new fluid or from assembly. But given the amount of air I was pulling again . . . I started second-guessing my 'the anti-dives are OK' boldness and decided to do a good flush forcing fluid into the caliper and out the AD per side. Fluid came out clean, which was good peace of mind. After more (and more (and MORE)) reverse, traditional, and vacuum bleeding (I really think the orifices are too damned small for MityVac to be much good with this system as opposed to my WRR or other bikes I've used it on - or I just need more patience - but it's good for keeping air from back-flowing into the system), I am finally getting slight pressure and good return from the piston. Tied the lever down again for the workday and we'll see if I come home to any magic tonight.

At least I got my other bike fixed to ride today - it's been a week.

 

Whatever you do, don't get brake fluid in the vacuum pump:

By the way, I'm starting to suspect that some of the magic of tying the brake handle and leaving it for a few hours is as much about taking a mental break as it is about time for the system/air to settle.

 

I just put on a new mc and twitched the lever just past where the switch clicks for a while before the air bubbles stopped in the reservoir and fluid ran from the banjo. Then had to run about a full 12oz bottle of fluid through the bleeder screw in a couple sessions over a 24 hour period to get all the air bubbles out at the caliper.

 

Took a break from the brakes (tore down the MC a 3rd time. Bled yet again. Ready to ignite everything.) and attacked my muffler rattle. Updated in this thread: https://www.xjbikes.com/forums/threads/xj700n-exhaust-collector-to-can-gasket.130066/#post-672867 Took a LOT of grunt, but got them off intact. Dumped a lot of crud out.

 

Wow, never seen those riveted plates on the muffler cans, typically that information is just stamped (engraved) into the metal. Very fancy.........

 

Oh, collectible! I don't know if it has any bearing, but it's an early run '81, I believe February build. Before they even stamped the full VIN on the neck, just the crappy half worn-off sticker on one side and the abbreviated stamp on the other.

 

Ended up borrowing an oscillating multi-tool from a friend to get enough of the old copper exhaust gasket off of the collector stubs to fit the new ones back on. Only munch them up a little bit. Took the opportunity while I had the cans off to give him a pretty good polish with some never dull and a buffing wheel. Not perfect, but cleaned up pretty well. Some before/after side by sides:



Got them bolted back on, and as @chacal implied in the other thread, it didn't entirely fix the problem. Greatly improved it though, and I think I can live with that. Maybe a really small shop vac nozzle down the collector could have gotten out some more gunk from in there, but just getting the chunks out of the cans is better than nothing.

Brakes are still not bleeding. Going to rip apart the master again and probably order some more parts from Len in a couple days. That part is really frustrating me, especially because I had a decent brake lever pressure the first time around but it wasn't good enough.

Had hoped to be able to ride this weekend, but oh well. Better safe than sorry.

 

I hold them upright, fingers splayed wide across the openings. , and shake up and down with a slight circular/oval-ar arc and continue one direction til nothing more comes out. Then, change direction..... the turn the opposite end up, the change direction. Etc..... I do that until there is no more rattles in any direction. I can feel the grit, particles, etc.... bounce past my fingers, and eventually there’s no more to feel it hear. It may be an hour or more of that but they eventually empty out. Just gotta get the crap to bounce into the correct tube inside in order to fall out. It takes time and patience.

 

That's pretty much what I was doing. Seemed to get everything but the most minute bits out of the cans. If I'm bored over the winter I might dive back in, but for now, they're good.

Full focus on the brakes again this evening. One more try ad getting things primed and bled, then I'm throwing in the towel and buying more parts and/or looking for a known-good master. It's gotten beyond risidculous.

 

I am SO close to being able to ride this thing, but I'm at my wit's end with these brakes. Any suggestions welcome from @hogfiddles @chacal @Jetfixer et al.

Recap ('81 Seca 750 REMOTE master):
Rebuilt master cylinder with kit form Len, reused plunger, piston, and spring.
Piston had been hanging on return, but I honed it again and polished w/ 1000 grit wet sandpaper, and it operates smoothly now.
Main hole and relief hole both confirmed clear w/ guitar string and compressed air.
New S.S. brake lines from Len.
New banjo bolts and crush washers.
Rebuilt calipers w/ kits from Len.
No current leaks detected.

Things NOT rebuilt/replaced:
Aforementioned reused MC parts.
Reservoir diaphragm
pipe between MC and distribution block
distribution block
anti-dive (was last rebuilt circa 2006, IIRC - no sign of leaking)
bleed valves

Over the last few days I've tracked down under-tightened fittings on 'pipe,' an under-tightened bleed valve, and I've had MC out and apart countless times to get where I am, which is CLOSE but still not there. And yes, I cleaned everything out thoroughly after honing/polishing. I've gone through SO much brake fluid (like 1.5 of the big bottles) and my freshly-painted calipers and showing it, sadly.

Symptoms:
If I reverse bleed up to the MC/pipe junction, and instal the MC primed, I can get one good bleed push (squeeze handle, open bleed valve, fluid comes out w/ no air, close bleed valve), but the MC never seems to refill. Reservoir is full but not overfull. I can pump it, or leave it sit all day, the lever returns via the spring, but it never builds pressure. If I reverse bleed, I can get a semi-stiff lever (about half-squeeze, can NOT put lever to handlebar), but even if I try the tie-down and sit a few hours routine, it doesn't get any better. If I just let it sit, it seems to get mushier. I've tried the trick of vibrating the lines and components, but the last little bit of air/spongieness remains, and again the MC never seems to refill from the reservoir after a bleed. I can pump it 100 times, fast or slow, and it doesn't build pressure unless I put pressure in from one of the bleed screws (reverse bleed). I've read a bunch of threads where eventually things just work for people, and that's what I remember happening in the past - being frustrated, and then things suddenly working as expected - but I've now been at this a full week, and I'm still not quite there yet.

Any guesses on what the problem is - port(s) blocked by air or debris (any time I bleed, top or bottom, the fluid is coming out as clean as it went in. In the 4 or more times I've had the MC apart, I've yet to find even the small port blocked)? Improperly seated seal? Worn non-replaced components? Something else? Help me, Obi-Wan, you're my only hope!

 

Is it possible you are bleeding off more fluid than the master is able to draw back in? Try cracking the bleeder real fast open,close/on,off like flicking a light switch quick.

 

After all that, I had solid brakes this morning. Even left the string off for a while and still good. There's a little slop at the start of pull, but I'm starting to wonder if it was always like that and/or can come out with cable adjustment. I'm just so used to my other bike.

So, I rode dirty (no fairing, thus no headlight/turn signals - again, do as I say, not as I do) up and down my quiet residential nearly-dead-end street a few times. Other than that dang collector rattle, she's sounding and feeling great. SUCH a different feeling from my 250, though. Different lever angle and pull (easily 2-finger clutch and brake the 250), much lower (though still upright) seating. Footpegs further back. What a flashback after not riding it for 11 years.

Still have a few issues I'll need to sort before a real ride, such as a sticky side-stand switch (I've had to lube it in the past), and get the fairing on, but I'm feeling a lot better than even 18 hours ago.

 

Has anyone come up with a decent way too recondition these mirrors?

 

Yes mask off the mirror glass , I used 600 grit sand paper wet sanded surface. Primed and let dry and sprayed with semi gloss black paint .

 

Sounds reasonable. Another winter project. Thanks for the suggestion.

For some reason I had in my head they were originally a bit rubberized, so was thinking something like spray-on plasti-dip. But plain paint is likely much more durable.

(And yes, I just happened to be on the site when you replied, thus the quick turn-around. )

 

Some crappy pics are on my phone (I’m on iPad), but I got the fairing back on tonight, as well as all of the side panels and such and made the all-important ride to my buddy’s house, yes even after 11 p.m. I was the first house he drove to when he got his license and vice versa. Always the first stop for a new car, truck, or motorcycle. So good. After that, I hit a gas station for a full tank, with a couple 60 MPH runs.

Just as I was thinking the clutch was feeling a bit sloppy, pulling away from a light, shifting into third, the clutch lever came all the way to the handlebar. Luckily, being so late, there was no traffic, so I was able to clutchless downshift back to second, and pull into a Costco gas station. Though it was closed, the bright lights were still on and a perfect place to troubleshoot.

Turns out the cable didn’t break, just came out on the bottom end, somehow getting by the little safety tab. I got it back in place and reset the slack for an uneventful ride back home. I also took the opportunity to take out some slack in the rear brake pedal, too. Did I really ride it like that before?

Also had the headlight cut out for a second (on a very well-lit road) due to the 9-pin fairing plug not being fully seated - something I’d seen before when messing with things, so not a big surprise.

On my 10 mile jaunt, a few things hit me - the 750 is a good bit louder at speed than the 250 thumper. It also reacts to tar snakes more puckeringly. But it gets to the WR’s top speed with only a couple gears and doesn’t FEEL as fast. And yeah, both handlebar sweep and more-tucked knees are going to take some getting back used to.

She fit like a glove that hasn’t been worn in 11 years. Familiar, but a bit crinkly.

 

Did another 30 or so miles this morning. Shifting this versus my 250 is like shifting a 1973 Chevy 1 ton pickup versus shifting a semi-modern sports car. You have to work harder for it, but it pulls so good. And said good, Even without the new pads made it to the rotors yet. Can two finger break. And with a little more workout, two finger clutch as well. Started a bath, but had to go pick up my kid from dance class.

 

BIG fairing. KG luggage / backrest system? Looking good......

 

No luggage just a sissy bar and rack, But yes, KG, well spotted. Originally the fairing had a stereo mount too, but I never got it working right so I ditched it. Craig Vetter disavowed this faring, though it is loaded with Vetter branded parts. Mentioned further upstream that it looks like this was a Yamaha XS 1100 special run.

 

If anybody has suggestions for replacing the rubber inserts on the KG luggage rack, I'm all ears.

 

Hers is mine I have the hard luggage set up .

 

Rode it to my 30th high school reunion last night. Seemed appropriate. The bike performed perfectly. I’ve got about 75 miles on that first tank of gas so far. My old eyes have a bit of a time seeing that speedo needle at night, though. Need a repaint on that thing.

 

Bike is looking good.

 

First commute in progress. Got me here just fine. Sadly, all that extra iron (frame) was no better at setting off the traffic lights than my little 250 is. LOL.

 

Better top end though!

 

Loads better. To be at 60 and have plenty to roll on without even downshifting . . . is nice.

 

With about 200 miles on the rebuild, I had my first breakdown. Well, second if you count the time the clutch cable noped out. About 3/4 of the way to work, on a turn, she started missing a little. At the next light, I pushed all of the spark plug caps to make sure they were seated and it ran smooth again. Made one stop, and it started fine and dandy. Then about 2 miles from work, it REALLY started acting up. I thought about trying to limp in, but decided to pull off in a landscape company's driveway, where I could get plenty of space from traffic.

At first, I tried pulling each plug cap in turn to see if I could isolate the missing cylinder, buy each pull killed the engine instantly. Got out the toolkit to start pulling actual spark plugs and look for a wet one. I pulled 1&2 then noticed my inline fuel filter looked a little 'empty,' so got distracted by that. I pulled the tank and found the petcock was acting fine, the filter just had a weird bubble, so I went to pull the 3 & 4 plugs. And bam!



The cap came right off the wire in my hand. Reseated thte cap on the wire and made it the rest of the way to work with no problem. Figure I should also be able to get home. Guess that settles my debate on what to do vis-a-vis resistor plugs vs. caps. I SHOULD probably just replace the coils while I'm at it, too, right? Hey CHACAL!!!!!

Granted, I didn't hear any bikes pass while I was disabled, but I was a little bummed no one stopped to check on me - though I had the situation well in hand. Glad to have the ol' Yamaha tool kit, but kind of wish I'd also thought to pack my multi-tool in case I need to trim some wire to get home. Also broke the clamp on my fuel line petcock connection, so note to self, put zip-ties back into the tailbag after the last clean-out!!!

 

I run Honda CB750 coils , these have replaceable plug wires and these coils can still be bought newand mount like stock coils . Cycle Recycle part 2 has these they are 39.95 each they also have plug wires and caps . I have used these on both my Seca's very happy with them. These coils are Hitachi which are the same manufacturer of stock coils.

 

Put a hundred miles on today with no problem from the spark plug wire, but I'll still look to replacing. Also dropped the latest batch of oil in preparation for repacking the clutch. I know if you put it on the side stand you don't need to worry about the oil, but I had Seafoam in there so I wanted to clear it out anyway. Came out nice and water like after a hundo.

By the way, I think I found my exhaust rattle.

Paging @chacal . . .

 

We have replacement clamps available:

HCP10714 Aftermarket chrome-plated header pipe outlet-to-collector inlet PINCH CLAMP, complete with attaching hardware, use 1 per pipe, for all XJ750 Maxim, Midnight Maxim, 1981-83 XJ750 Seca, and XJ750 Euro models. NOTE: original clamps are spot-welded onto pipe; spot weld must be broken to remove original clamps! Each:

 

Do we think that crack in the collector collar is going to be a problem or will the clamp deal with it?

 

Well, it's kinda hard to tell just from the picture, it sorta depends on how sound the metal around that crack still is. Honestly, it looks like that collector is sort of reaching its expiration date,you may be able to "get by" for now with a new clamp, but eventually it will need replacing (based on the pictures).

 

In other news, working on repacking my clutch, the posts for the springs have some pretty deep grooves, one moreso than the others. How bad is this?

 

First time l have seen spring damage to the posts. Looks like the pressure plate was moving allowing the springs to press on the posts. Marks look superficial in the bottom photograph. I would replace it if it was my bike but l am not an engineer.

 

No the pressure plate would be unlikely to move looking at a photo from my manual.

 

Interestingly, on the reassembly photos, the Haynes manual shows similar wear on both the basket fingers and the spring towers, with zero mention of addressing it as an issue. Huh.

 

Clean it up with some scotchbrite and reassemble.

 

That was another assessment I got as well. I'll get after it this evening. Wife's going to start wondering where all those green pads went . . .

 

Got the baskets cleaned up a good bit last night. Scotchbrite for most of it, but there were a couple bigger burrs I hit with 1500 grit wet/oiled paper. The mosquitoes started swarming and I didn't want to rush the reassembly job, so I'll hopefully get to it tonight.

 

Well gang, I messed up. Didn't feel like working on the bike tonight, but I did anyway, and I regret it.

Things were going well, had the new gasket prepped, had all the parts soaking in oil and slapped all of the plates on. Bolted up the pressure plate and . . . I snapped bolts. I'm going to say it was a combination of a crap Harbor Freight torque wrench (zero doesn't line up on zero, so was I at 7.2# or 12.2# or somewhere in between?), using the wrong tool for the job (should have gone to inch-pounds instead of using the bottom end of the foot-pound wrench's range), and not stopping when things felt wrong. I finger tightened then got out the torque wrench, progressing in a star pattern. Never did click. Just when I was thinking, "Man, that's a lot of turns," the first bolt snapped. I cussed, then went to start backing off the others and a second snapped (not the one I was loosening, but one next to the first). So mad at myself, as I once did this with an oil filter bolt on my 250 - small torque needed, wrong wrench used. SO mad. That one was easy to fix, as I just had to remove the filter cap and enough of the bolt was sticking out I could back it out with pliers.


But things went from bad to worse. I got one broken bolt extracted, but as I was working on the second, the ez-out came lose, wedged against the thread, and the bolt tower chipped.

REALLY should have just gone to bed.

So, @hogfiddles remember that inner basket we decided I didn't need? Gonna need you to check if you have one - or I can put an APB in the Wanted section.

Please don't berate me, I'm already kicking my own rear enough, but someone, please learn from my mistakes. Ugh.

Going to have to add to and finally get that order in to @chacal as well. *big sigh*

Also going to need a 29mm socket. The hub nut is 29mm, right?

 

Hub: yes, 29mm socket.

Hub: yes, we have some good used ones, as does Dave I'm sure.

Beration: I'd bet that there is no outside entity that could berate you as much as you are probably doing to yourself right now. Luckily baskets are easy to replace and somewhat inexpensive.

 

Thanks for calming me down a bit. Since I need to get other stuff from you anyway (hub bolt and safety washer are to be replaced, yes? And new bolts, of course, and those other things I'd priced out), I'll probably just go with yours. I think Dave had said he'd have to dig around a bit to see what he had. Going to bed now, but I'll send you and updated parts list in the morning.

Thanks again.

 

I’ll see what I got. I know I have several in parts engines, I may have one or two laying loose. I’ll look.

dfox

 

Not to make it worse ,I snapped two as well all I had to was take a pick and bolt came right out , no easy out needed .

 

This could happen to any of us. Don't get yourself down. This is what I call " paying for your education "

 

I wouldn't worry about a wee mistake like that. Easily done.

 

I got the first out and the second most of the way there with just a fine screwdriver, but I think it was getting hung up on some mangled threads at the end. C'est la vie.

 

Thanks, Dave. We'll see what Len has as well, I'll let you know if you should call off the dogs. Love this group.

 

Might as well replace the main drive bearing while the basket is out, assuming your clutch is the same as an XJ650 Maxim.

 

Finally got my parts order together. Don't know the shipping fairies will have stuff to me by the weekend, but I hope to be rolling again soon. Been in the 50s the last couple days - it'll be nice to commute behind the windshield again instead of out in the open on the little 250.