New xj750 owner

Hey guys. Long time lurker here. Finally managed to sign up. I've been riding and wrenching on bikes since the 1st yamaha (dt80) I got on my 8th bday. That was 21 years ago.

Anyways, I tend to pick up bikes for very little money and fix em up myself. My latest project is a 1981 xj750 seca. Got her for $300 with the title. She needs a battery but looks, runs and rides good. Got a slight sputter but I'm guessing that's the carbs needing cleaned. I need to familiarize myself with this yics system. It has me confused. Actually, this bike has so many gizmos. I've never seen anything like it.

The bike is metallic red and has this huge front fairing on it. I can't find much info about this or if it was stock? I'm thinking about removing it. It's in good condition though. Just bulky and not my style. Also can't for the life of me find a right side panel. I've looked everywhere I can think of on the net. Sorry for the long post. Just wanted to say hi and all. I'm from southeast ky by the way.

 

Great to see you signing up and posting your first post. Glad that you found a nice bike for a nice price as well. As for the YICS system, not much to worry about. Some say they need to be cleaned with picks and air to make sure the mixing chambers work right. Some say you need to make the tool to isolate the chambers when you do a carb sync. You will have to do some research and find out what you want to do.

I made my own tool and did the sync and I can't tell the difference with or without the tool. How are all the electrical items working? That was the issues with my 81 750R.

Looking forward to following your progress.

 

Welcome Jamie
That fairing would have been an optional one from Yamaha that looks like this? There may be someone here that has your elusive side panel.

 

If the fairing is mounted to the forks (turns with the bars) then it is the optional sport fairing.
If it is fixed to the frame it is the fiaring for the touring package, which became standard for 1983.

It was big becasue it was actually meant to work without the rider having to hunch over.

 

Thanks for the replies guys. The electronics are in working order but the fuse box looks a little weary. The fairing is the larger one that mounts to the frame. It doesn't turn with the forks. I'll try to upload a picture.

I've thought about what I should do with it. I have the urge to build a bobber with it but it's in good condition for the age. I'd hate to destroy an all original bike.

 

fix it first ride it go buy an xs if you want a bobber

 

^^^ +1 I agree, that is a nice looking bike for a bobber, but it is your so do what you like. Start out by getting is safe and enjoy riding it for a bit before you make up your mind.

 

She's alittle of an a odd one, only in that the touring faring was not sold without the rest of the package very often (so far as I've been able to discern).

I don't see the steering damper. Would you mind looking beneath the triple-tree and see if there is a big black radio-knob looking device attached to the stem?
I think you have one of the bikes that was built when Yamaha was transitioning it to only being sold with the touring package.

 

It has a steering damper. It's clamped to the left fork leg. Looks kinda weird like someone just threw it on there. I've seen these bikes with the touring boxes and all on the back. Wish I had em on here. I'll get better pics when I'm off work. I think she'll clean up nicely.

 

Good looking bike! Runs and rides for $300.... I would give you triple that anytime! Nice find!

Welcome to the Xj family.

 

OK. I missed the upper clamp for the damper before. That is the correct one for the bike. It was admittedly an afterthought, but works well. Yamaha didn't intend to make the Seca 750 a touring bike to start out with.

 

Yeah it kinda looks out of place to me. It mounts to the frame then clamps onto the left fork. I've never had a steering damper on a bike. It'll be interesting to see if it makes a difference. I was gonna try one on my cbr600rr but never found the need for it.

I think for now I'll leave her stock. She's an odd bike compared to what I'm used to but that's what I like about her. The fairing is starting to grow on me. It'll be especially handy in the fall and winter.

 

The steering damper is required if the fairing is mounted. The bike will tend to headshake without it, especially if you hit a bump midcorner or have gusty crosswinds.

 

Thanks for the tip. You just saved me the headache of finding out the hard way.
I'm gonna tear into her next week when I'm off work for a couple days. Gotta make a list of what she needs.

So far she'll need a front tire, battery, carbs cleaned (possibly rebuilt), air box boots, air filter & some new fuel and vacuum hose. Also the front brakes don't work. They're strange looking to me lol. Never seen this brake setup before. The master cylinder is down in the fairing & the lever pulls a cable. I noticed it has anti dive forks also. What is this wizardry

 

Thanks man. I honestly just got lucky. My cousin's neighbor had it and I just happened to be there when he had it out one day. Being the bike nut I am I had to ask him about it. Then he tells me it's too big, he can't hold it up, etc. Then he was like gimme 300 and it's yours. I didn't even try to chew the price down any.

 

It's just coolness beyond compare. Yamaha wanted a clean look for the bars, hence the remote-mounted master cylinder.

You will want to rebuild the whole brake system. The anti-dive is probably OK, but you will want to make sure that the little pistons on the brake side are moving freely otherwise the system won't work at all and you'll think that the forks are crap.

Even if you don't need to rebuild the forks it's worth knowing what is inside of them, and the anti-dive.
Anti-Dive Fork Explosion
Doing the 750 Seca's Forks.. (Rebuild.. now a HOW TO!)



@chacal is the only source for a good rebuild kit for the master cylinder that I know of. Same for the anti-dive parts if you need any. He was one of the few people to buy up NOS stock before the dealers threw it all out (the only available master cylinder rebuild kit is aftermarket though).

We don't have a rebuild thread specifically for the Seca 750 because the manual covers that really well (and it's not so different from any other master cylinder).

HOW TO: Rebuild Your Master Cylinder

Bleeding the brake system on the 750 Seca can be a bear, so this will come in handy.
brake-help.108235

 

Thanks. I'm sure I'll be back on here once it comes time to source the parts and info. This one missing side panel is gonna drive me nuts. Everything else is there so I got alot to fix before worrying about it really. Gonna pull the carbs & petcock to see how dirty everything is. I may be hunting for some rebuild kits here if the seals are all dried up. I hope I won't need to break the carbs apart from each other. The bike sat for a least 2 years in storage. Maybe longer.

 

I too was one of those that hated to break them apart, but it if part of the game with these older bikes. Not just the gunk in there, but the rubber parts in there that just break down with age. Watch some vids and use a camera if needed to help keep track of the parts and they way they come apart and go together. The little jet in the bottom of the float bowl and the emulation tube (under the main jet) are normally gummed up. Keep working on that great looking bike.

 

I've seen others with parts of the touring package. The front fairing has lowers which are missing on your bike. I see engine guards installed and I'm not sure the lowers and the engine guards could coexist. Previous owner likely removed the lowers and installed the engine guards. The lowers are very breakable. No bag assembly either.

 

Ahh.. I was actually wondering about this. It seems like something was missing. I noticed the mounting holes for a lower section. Thanks!

 

There are two types of case guards for the XJ750. Both can be fitted with the full touring package installed.
The lowers tend to be susceptible to melting, and cracking. It's not that uncommon to find them missing.

It's very possible that someone found the fairing and steering damper on Ebay and installed them well after the bike left the showroom.

 

Thanks. Will do. I've never actually split 4 carbs before. I did the carbs on my cb450 and gs450. Both were twin cylinders with dual carbs. I'm gonna be researching for a week before I decide to break em apart or not. They may just need a thorough cleaning. It runs good. Petcock leaks a lil.
I need to check my valve clearances before I do anything though. Gonna read up on that 1st.

 

The rubber parts that are letting the petcock leak are probably the same age as the rubber parts that allow the carbs to work without vacuum leaks.
If you know how to break a 2-carb rack you can handle a 4-carb rack.

 

Thanks. I did notice the fuel tank has been painted. Maybe the entire bike. It has paint in the petcock lever. It's hard to say for sure if it was factory or not. Alot of hands could have been wrenching on this bike since 1981. If it's not factory I can't tell.

 

The painted petcock lever is not factory, but it does look like the factory color was used.

 

You're right. If I rebuild them I may as well do it once and do it right. I tried to do a quick rebuild on my 1974 cb450 at first. It didn't run any better. It was my very 1st carb rebuild though. I hadn't even thought to set the float levels. I was young and dumb. Still am to an extent, but not as bad as my teenage days lol.

 

I removed the fairing to inspect the master cylinder and see why I had no brakes. I found this cobbled up mess. Someone basically just threw this fairing on after beating the headlight mounts flat and making a shoddy bracket for the bottom part.

The master cylinder wasn't even hooked to the reservoir. The fairing bounced alot on the road when I took her for a ride. The bracket secured the bottom but let the fairing bounce up and down. So now I'm trying to decide if I will keep the fairing or scrap it and put a regular headlight on it. There's a mile of wiring to hide if I opt for the latter.

 

Home made bracket I mentioned.

 

All that wiring will fit into the factory headlight bucket.
Bending the headlight mounting ears is SOP when instaling the fairing, but those are bent wayyyy too much.

I'm sure someone here has the correct mounting bracket for the fairing. Placing a wanted ad is free here.

 

Thanks. I'm gonna focus on gettin it running good for now. I took the carbs off today. Are these hitachi carbs? Do u know the part number for the rebuild kits? My airbox is cracked and a couple boots are ripped so I gotta repair that too.

The parts list keeps on growing haha. Gotta rebuild the carbs, petcock, airbox, get a battery, front tire, check valve clearances and then install carbs and run it if the valves are in spec. I love working on these old clunkers though. Wouldn't trade it for anything. Found an old xs650 nearby but the guy wants too much and I already have my hands full.

 

Carb pics

 

@chacal is the MAN to get you all the carb stuff and new boots to the airbox and fuel tap kit( many jobber ones do not fit correctly)
He has been tagged and should chime in soon.

 

Carbs are Hitachi HSC32.
Start a conversation with @chacal. There are a few rebuild kits on the market that simply do not work correctly. Chacal doesn't sell those.

 

Thanks. I haven't figured out how to message him yet but I'll keep trying.

 

go t his web site www.xj4ever.com his email is listed.

or go to your inbox button hover drop down says start a conversation click and put chacal in recipenaints

 

Go out onto your door step and yell, "HEEEERREE Chacal Chacal Chacal......"

 

sort of like beettlejuice

 

Haha. I figured it out. I'm on my phone so it's aggravating sometimes. I felt like an idiot when all I had to do was click on his name and select start a conversation.