Differences between '82 750 Seca and 750 Maxim

Hi! First post... I'm a newbie on XJs. Closest experience is owning an '81 Virago for a year.

I'm going to look at a 1982 XJ750 Maxim tomorrow. (I wanted something similar to the Virago, but without the shabby starter that sounds like a broken coffeebean grinder.

Problem is, I'm having a hard time getting good info on it. When I do searches, Google tries to send me either to a 650 Maxim or a 750 Seca. So, not much to go on.

Anybody got good info on these? And, aside from a few obvious design differences, what are some of the differences between a 750 Maxim and 750 Seca?

 

Maxim is a cruiser with rubber engine mounts. Seca is more sporty with solid motor mounts to strengthen the frame. Seca also has slightly hotter cams, taller gearing, and anti-dive forks.

XJ's are not immune to the starter clutch giving out and sounding like a can of rocks, but they are not as prone to it as the early Virago's are.

 

cosmetic the shape of the gas tank ,seat and seca has a taller tire. 82 maxim has the atari setup rectangular head light and aux light as does the seca

if you look at the photos on the home page at top you will see the seca 81 and 82 and 83 are shown


seca 18 inch rear tire maxim 16 inch rear tire

 

maximseca

http://www.motorcyclespecs.co.za/model/yamaha/yamaha_xj750_maxim 82.htm


http://www.motorcyclespecs.co.za/model/yamaha/yamaha_xj750_sega 81.htm

 

I saw that entry on motorcyclespecs.co.ca, but wasn't sure how accurate it was, because they show the model years as only 85-86 for some reason.

What are some things to look for on this bike? Its at about 45k miles. I think i read to watch for rust around the tank petcock, but that's it so far.

Hopefully, all is well. It seems all original and well maintained.

 

Welcome Both bikes 650/750 Maxim or Seca are shaft drive bikes ...very little maintenance compared to a chain driven bike. Since you are new to these bikes stay away from a bike that has PODS look for one that has stock airbox ... The reason is unless you know about jetting and take the time to try to get it tuned this is best not something to attempt right away. Yes (no fan of pods ) On the upper right corner of this page is xj4ever click on Chacal had most parts fantastic service and will be the correct parts , read the information overload . I had an 82 Virago if you upgrade to the kit Dr Virago sells the stronger spring fork and shim kit it really helps . Well good luck in your search.

 

any paper work that owner has showing parts or service. at 45k miles you are at the point of valve shim clearance check, wheel bearings brake rebuild. ask about brakes but unless he has paper look for date code on hoses and tires

rust look at and under where sidestand is for frame rust.
you are buying an old antique motorcycle expect to put 500$ into min right off . if it runs good to start with your considerations are brake system rebuild of master cylinder both calipers front pads rear shoes.
read this thread
SAFETY ALERT Drum rear brake bike owners please take a look page 9 has a few good photos and on page 8 you can see a set of my shoes warning the jb weld is just my sense of humor do not even think of using JB weld.
most of the photos are gone but basically if the rear shoes are old they delaminate . the brake matrial falls of the metal shoe and you come to a stop real quick and unexpected would be very bad in a corner. I have had it happen to me rear wheel locked up just out of a corner

 

Well... it's official. I'm a bonofide member of the XJ club now after throwing down 1200 bucks.

I didn't see any obvious rust, other than a little surface stuff on the top of the forks, where the bars connect.
One scrape on the right exhaust pipe, but no other signs of being dropped.
Still the original glass fuses. I'll probably replace that. All controls worked.
Back tire's bald - I'll replace both.
The engine seemed a little fussy, and slightly rough. Seemed to start well, for the most part. But even after a 10-15 minute test ride, I got the choke about halfway closed and it'd die.
I didn't look at the brakes closely ( because I plan to refurbish them anyway), but on the test ride, I had to press pretty far down for the back tire to grab. Not sure if the pedal's adjusted wrong, or just really low on pads.
Other than that it rode well. A little sluggish below 2000 rpm, then picks up pretty well. The clutch seemed just fine, but the shift lever was stiff trying to toe it back and forth between gears - made worse by the fact I forgot to bring proper shoes and had to test in thin canvas shoes.

In other words... a new project begins... I welcome all suggestions (though I should probably move to a new conversation string for that)

 

(I'd post pictures but the spam filters won't let me)

 

You gotta have 5 messages before you're able to post pictures.
Check the shoes on the rear brake, they're prone to delamination over time.

 

your bike runs off of the pilot jets untill 2k rpm

sounds like you were running offf of the choke/enrichment circuit untill you shut it off

you NEED to clean the carbs

you could keep posting in this thread but if you start a new thread link bqack to this one then keep all your questions to the new thread

of course if you just have general questions they can be asked in seperate threads.

or in threads about what you are asking about . like tires a few threads on those
or if you wanted to ask about handle bars and what other people are using

 

Got it. Yeah, maybe I'll keep my posts here, so it's all together in one project then. Already ordered a repair manual online. Next up, some brake parts.

Thank you for your help!

 

One item to add to the list are new brake hoses ..upgrade to braided stainless and rebuild calipers seals are most likely original this will be item at top of the list. Take carbs to church and do a FULL tear down...Spray carb cleaner will NOT get into the small passages of the carb . NEVER EVER trust the P.O. (previous owner ) unless you know them that something was done such as "carbs have been cleaned" Best to walk around bike make a list of things to do to make bike safe and reliable, brakes,carbs,valve adjustment , oil change , Battery check (fluid level unless it is an AMG battery) all things to check.

 

Ok...First couple of questions... I was looking at parts to get, starting with oldbikebarn's website. I found two different carburetor rebuild kits. I wasn't sure which to get. I think I remember seeing that the Seca and the Maxim have different carbs, so I thought I'd ask. One's for xj650s and xj750s - the other just says says xj750. But neither says "R" or "J". ( here: http://www.oldbikebarn.com/parts-by-model/yamaha/xj750/carb-kits-parts )

Also, I saw they sold sintered brakes. What's everyone's opinion on this for an early 80s bike? My vote is no - I imagine them tearing the metal up too much.

And you're so right, Jetfixer. Considering the PO already said contradictory things while he was yammering, and was selling the bike for a friend. He had no paperwork except a clean title. I think he put some additive in the tank to get it going, but I can't be sure. I worry about any of that fancy stuff. Reminds me of a time I had to severely flush a car engine completely gummed up with stopleak sludge

 

Both 650's and 750's use the same Hitachi carbs, just different jetting. The carb kits that online retailers sell are just general carb rebuild kits that will not have everything you will need and extra parts that do not even fit your carbs.

It is highly suggested to order your carb kits from Chacal, he will sell you the exact high quality parts that fit perfectly. He knows everything about these bikes and will not steer you wrong!

 

^^^+1 Go to the top right corner of page to xj4ever ...chacal has the WHOLE carb kits and will be the correct kits , as well as all the brake parts, hoses, etc . Avoid buying from eBay the kits there are NOT I repeat NOT the full kits IE do not include Shaft seals and fuel rail O rings. My favorite adage "Buy the best cry once" Face it you will spend between 3 to 5 hundred dollars to rejuvenate the bike , but it is still cheaper than buying new and having a payment , if you live in cold climb then 3to 5 months of no riding and making payments not real fun.

 

Makes sense to me! I've definitely found myself sitting with a a pile of 'leftover' parts and gasket bits I had to snip to fit, after buying a rebuild kit.

Any thoughts on sintered brake pads? Am I right to steer clear?

 

steer away , stock pads are fine unless you intend on doing track racing.

 

Ok.. The bike is safely home. I took a few reference pictures - you're welcome to check 'em out. Maybe you spot some things of importance: https://www.flickr.com/photos/22685288@N07/albums/72157682962517942 I spotted a few more dings, dents and blemishes of being an old bike. And... somebody's had a charmed life, too, maybe? Over 32,000 miles and 35 years, they rode that bike with the same brake lines that came outta the factory in '82.... and...on that back tire.

I've got all new brake lines, master cylinder kit and pads on their way. I'm stuck waiting til next payday, after it dawned on me I should've gotten new wheel bearings, too, sinc I'm taking the wheels off.

A question on removing/replacing the old wheel bearings... I saw the xj4ever site has a "wheel bearing removal split-collar driver tool" and a set of instructions, if one is too cheap to buy said tool. But, couldn't I also use a slide-hammer and one of those blind bearing pullers?

In everyone's experience, what's the best way for me to get these out? I don't know yet whether anything's rusted tight on the inside, but I suspect it might not be that bad.

 

you can buy a drift and punch them out from the opposite side there is a spacer between the 2 bearings you have to move it aside a little.

you may also consider some freeze spray on the bearings to chill them and shrink them to take them out. I put my new bearings in the freezer for a few days to chill and shrink for installation.
an upside down can of caned air works too

keep the edge sharp (flat)
getting the first bearing out is the hard part

 

To my eye, that's a pretty complete Maxim... Rear shocks are not original, but that's all I see. Someone more experienced with Maxims might see more, but it looks like a good starting point to me. Has a compression test happened yet?

 

I haven't yet. Still gotta pull that stuff out. The previous owner (of only 2 months) said he did a compression test. He couldn't remember what it was at and didn't know what it should be, but he said that all four matched. Not that I trust him, but I'm going to focus on wheels and brakes first. I'll test just before I pull the carbs out for a rebuild.

On another note, I went out this morning to put it up on the center stand, and noticed that it's been leaking a little. Not a fast leak. But a leak, none-the-less. right on the bottom of the bike. I haven't looked closely yet, and I could've managed a better pic than this, but breakfast beckons!

 

could be the oring in the oil level switch right above the oil and muffler clamp.
you may want to replace the crush washer on the drain bolt too

 

This weekend, I got the back tire off, and checked out the brakes. Plenty of meat left on the brakes, but I'll replace them anyway.

The part that concerns me is that there's hardly any movement in the control lever, and the cam squeals out a complaint when I move it around. Guess I'll have to take that apart to clean and add a dab of grease in there.

I knew something was off with the back brakes!

That's as far as I got, though. A damn monsoon blew through. I had to cover everything up with a tarp and hope for the best. I just sat back and watched the trees swaying. A neighbor's awning even ripped off in the wind and blew back down about 20 feet from my vulnerable bike. I'm a little jealous of you people with the luxury of having a garage!

 

Shocks are correct for thre bike. Good looking bike to start with. Where are you located? Chances are, a list member is nearby to help.

Dave f

 

I live a bright, sunny little slice of hell, called Phoenix!

 

ok.. maybe a beginner thing. I missing something here and need some suggestions.
I took apart the rear drum on the '82 Maxim. New tires, refurbished the drum, new pads and now I'm putting it all back together. Almost there, but one irritation left:

When I try to get the axle in, I'm having a hell of a time getting everything to tighten down where the new cotter pin can go into the hole - seated in one of the castle nut grooves like it should be. I push the axle back out a bit trying to line it up, cinch down the pinch bolt, and go to work, then find it still doesn't line up. I've got the washer in there on both sides.

Every time, as I tighten down, I find the axle end has pushed out beyond the castle nut, to where the holes are past the castle nut grooves. Furthermore, can't even get them to line up. For the moment, I dropped in the cotter pin when it would fit and took a couple pictures to see if somebody spots what could be wrong.

But i think this is just a case of "what's the trick"?

What I've got right now:

 

Nice, clean Maxim, looks pretty much fully stock and pretty well treated.

I'm largely talking out of my backside here, but I wouldn't really worry about the cotter pin. It's still going to prevent that nut from falling off, and while it could back off a little bit in theory it's really, really unlikely for that to happen and shouldn't really do much of anything as the swing arm is securely holding the wheel in place.

With that said, an easy fix here is just slapping a washer underneath the castle nut, then you're golden.

But I'm sure someone more knowledgeable and less hacky than me will chime in if there's something really wrong with this.

 

Did you put the long spacer back inside the punkin housing before putting the rim back on?

 

Punkin housing? ... I think you lost me there - I don't know that term. Do you mean the final drive unit? The only spacer I remember seeing is the one between the wheel bearings in the hub. That's definitely back in. When I pulled the wheel off the final drive, I don't remember seeing anything. Just the drive hub gear on the tire, and the gear on the final drive it fits onto.

 

So, when you tighten the castle nut, the shaft gets pulled through, slipping past the cinch clamp?



XJ4Ever.com has a great tutorial on removal and replacement of rear wheel. Go to page 15 for replacement instructions.

http://www.xj4ever.com/rear drum brakes.pdf

 

yeah... that's the instructions I was following, alongside the books.

Looking it over again, there is one thing I didn't catch: Referencing Page 15 of Chacal's instructions. On my bike, the bolt is shorter and never had a nut and washer underneath for that pinch bolt. Not sure if it has anything to do with my issue, but Maybe something I need to look at.

(in fact, you can see the difference, in my picture a couple posts up)

I suppose that's a nut I can find at a hardware store, but... thoughts?

 

I looked at your pic again...I don't remember the holes being so close to the end. I wonder if yours was just drilled funny.i. I'm gonna check mine to compare.

 

it is all in how you bend the cotter pin.
rotate the eye of the cotter pin 90 degrees then you push the leg of the pin into the slot of the nut bend leg down to follow body of nut. the other leg is bent up to follow around shaft
this will give you 2 shear points in the slots and look a lot better.
use needle nose pliers to shape and push the leg

 

is this your cotter pin

this is ugly and as you can see the holes for pin are way out
turn 90 degrees bend trim and cut
head of pin is in slot lower leg is bent into slot and follows nut
outer leg is bent around axle end
finaly tap it with a rubber mallet or a little block of wood to bring it home

I use stainless cotter pins and shorter than one shown in photo

 

disregard this little entry.. something glitched, while trying to post from phone

 

also in the FSM it states if when torqued the holes do not line up with slots torque it a little more to line them up.

pinch bolt is the last thing you tighten washer is there to keep bolt head from chewing the swing arm boss

just a bolt and washer 9 and 10

 

happens a lot with phones


also the 2 washers on the axle are different parts maybe different thickness did you reverse the locations (if this is possible)?

 

Maybe I'll give that a shot. I noticed that later last night, too - that the pinch nut is tightened after. Problem is, it's not technically possible to do the pinch bolt last, because if it's not tightened down, the axle spins when trying to torque the castle nut to 77 lbs.

Is it at all possible the wheel bearing is pushed in too far? I don't think it'd have anything to do with this, though. and the spacer is in there, so I assume it's fine. I just remember on one side, when pressed in, the wheel bearing wasn't flush with the hub edge. it was about 2 or 3 millimeters in.

(but I think now I'm just throwing thoughts at the wall, in case something sticks!)

 

on a side note, looking again at the first of my pics above, you can even see the difference in position. on the pinch nut site, see where there are a few wear marks to the left of the pinch nut location? That's about how much the axle is pushing past the castle nut, and shows that it's not where it lined up when I took it apart.

 

thats why there is a hole in the right side of axle for a rod to hold it . but you could tighten pinch to torque axle then release it and retighten it

every component on axel works as a spacer

 

Sorry.. just saw you added something. Yeah, the washers stayed in their location. I kept them with their respective part/side.

I might just try and get things lined up a little better, then try your idea of turning the cotter pin 90 degrees so it catches some of the nut groove.

 

if spacers are in there no.

but you are over thinking this now. your goal is to secure the nut with cotter pin all my pin holes are out past the end of the nut not completly but past it . that is one reason I install the cotter pin the way I do another is for the clean look.

the washer /nut could be worn from years of removal

 

my pin holes on the 750s are half way past the slots

I just measured my nuts one is 14.7 mm the other bike is 15.7mm could be you have the wrong nut on the shaft

did you forget the washer in side the axle assembly spacer flange in the assembly drawing

the pinch bolt will not affect the overall length of axle assembly as the bearings washers and spacers cause the lenght

 

Looking at the rear wheel diagram in the service manual, My bike is a little different. There was no spacer flange that I saw, but the spacer itself was also not just a tube - it had a flat plate on one end of it. I put that back in the way it came out.

I've been taking little video snippets along the way, to keep track of stuff. Here's what came out:
https://www.flickr.com/photos/22685288@N07/35875378390/in/album-72157682962517942/

Or were you talking about a different part?

 

I believe the same thing happened to me the last time I had my rear wheel off. I had tightened the pinch bolt before torquing the axle nut and had the same problem. Loosened everything then torqued the axle nut while keeping it from spinning with a large screwdriver, then tightened the pinch bolt.

I would try that if you haven't already.

 

Regarding the castle nut, I've gotten it as close as I could, and turned the top of the cotter pin sideways so it catches some of that castle nut... and moved on to the brake Master cylinder.

A couple general questions just for the sake of pickin' brains of the knowlegeable! I've taken the master cylinder apart and I came across a couple anomalies, that I'm curious about.

First, when I pulled the boot off the end of the cylinder, after a bit of struggling since it obviously hasn't been touched in some time, I didn't get just a rubber boot. There was a thin little wire that pulled out with it as well, all broken up. Seemed to be part of the boot, spun around it's base. Thoughts? I figured maybe it was just an older way the boot had been manufactured. I didn't see anything similar in the rebuild kit, unless it's inside the new boot.

Second, I noticed a wear mark in the center of the little piston face, probably from vibration of something loose rattling against the end there. I got the complete rebuilt kit with a new one, so no big deal there. But...thoughts? Things to tighten down? maybe that brake handle is a little sloppy and loose? I hadn't noticed it before, but I've only rode the bike once.

Finally, I think my sight glass is some sort of hybrid! Or I don't read well. (By the way, my little screwdriver poked through with a half-pound of force. Anyone out there who hasn't replaced the original sight glass (plastic) - DO SO! You could be one flying pebble away from brake fluid pouring out as you fly down the road.) Anyway... back to the hybrid. In Chacal's instructions, he describes two versions. a circlipped sight glass and a glued sight glass. Mine was the glued in one with the slotted metal disc behind it. But once I cleaned everything out, and pulled out a little clear plastic ring, I found what looks to be an o-ring embedded back in a recessed area, just past the bored hole and lip where the glass sits. But the o-ring is only mentioned as being in those c-clipped (type b). I just thought I'd ask.

Tonight, cleanin' up the master cylinder and putting it back together with new guts!

 

Hah! a fun discovery I just made... I've been curious why the previous owner would've wrapped the rear brake pedal with a few inches of black electrical tape, but just never bothered to take it off until today. I finally unwound the tape and found he'd stuck a shaved down spare key to the inside of the brake pedal lever. Score!

Not that this is where I'd hide my spare, but whatever. Maybe the p.o. was a forgetful guy and needed a good backup.

 

nice idea or you could just put it in your wallet

 

My old Civic came with a plastic key molded into a credit card sized rectangle. One use only... pretty neat!