1982 XJ750 Maxim Build

Hello all,

Here is my first ever motorcycle/mechanical project. It started off as a bike that I purchased from a friend. It ran but had some issues, and I knew I wanted to modify it but I did not know how, or where to start. When I got it in August I simply wanted a "cool looking" bike to ride and I thought that the bobber/cafe look was something I was interested in.

I started spending some time on XJBikes.com and realized that my bike wasn't exactly conducive to that "style" I was going for. The shaft drive, the odd frame proportions, the mag wheels, etc. At that time I figured I would focus on safety and getting the bike to run perfectly, then see what I learned along the way. I figured looks could come later.

XJBikes has a wealth of knowledge for these things and it's a great community. I learned a ton from them over there and still post frequently.

I think that the biggest cosmetic hurdles these bikes have are the inherently "cruiser" looking gas tank, the triple tube frame, and also the frame bend near the tail. Whenever I notice the few and far-between excellent looking XJ's, a lot of that stuff had been changed, so that's where I started.

The day I brought her home:



Carbs completely disassembled and cleaned. Having never worked on carbs before (or anything, really) I figured being organized would be important. It was, and it went without a hitch:



I forgot to take more pictures, but I also checked compression, which was in spec, and also changed the out of spec valve shims.

Then I added pod filters and synced the carbs. I want to note that these CV carbs are a real pain and pods probably wont help with that. I did, however, opt to keep the stock carb to airbox boots and so I used those instead of the stock small boots that came with the pods:



I am told that this should help prevent the turbulent airflow many experience when installing pods into CV carbs. We shall see, but I do know that syncing, idling, and revving with the stock exhaust seemed to go very well. Mind you I'm doing all of this out of my basement so I wont really know how it responds until I can ride it in the spring.

If it needs re-jetted, so be it. Now that the airbox is gone I can get the carbs on and off in a matter of a few minutes. The other beautiful thing is that the entire motor is in spec and the carbs are zestfully clean, so diagnosing problems shouldn't be too big of an issue.

Now I am ready to tackle the welding of a tail hoop, cosmetics, and wiring. I'm scared of wiring, so I may very well contact the gentleman (men?) at SparckMoto to handle that. I really wanted to try and tackle it myself but there's just too much else to do before spring, and I have another bike I'd like to get working on.

So here's where the bike stands now:

I replaced the stock gas tank with a tank from what I believe to be a late 70's CB400 Hawk Tank, as well as a round headlight (for those of you that don't know, the '82 Maxims came stock with a horrific Rectanglular headlight and large "Atari" speedometer. At the time, I'm sure it was the pinnacle of technology but...it had to go. I won't paint the tins for a while but I wanted to strip the paint off with a wire wheel.

I learned afterwards that I probably could have just used aircraft stripper and my life would have been much easier. Oh well, I'm learning. I have no idea what color scheme I will be going with, and I still haven't decided what combination of black, silver, and polished I'm going to use on the engine.

So, the gas tank fit the frame fairly well with a little interior pounding of the tank mounts. Obviously the back will need fitted but I will weld something there soon.


I am having a bit of a fitment issue, as the Petcock is resting on the carbs, and if I lift it enough to give it clearance, then there's no way I'll be able to have a smooth flow from the tank to the seat. (Pic below is with the tank lifted way up)



My thoughts are that I'm just going to lose the petcock, attach a hose from the stock tank bung, to an inline shutoff valve, to an inline fuel filter. Does anyone here seem to think that will give me any issues? I really don't want to move the Bung completely, as the tank is structurally sound and I'm not a good welder

Next comes the seat. Take a look here to see what I mean about the odd frame dip in the center area, and note that this is where I want the tank mounted.



I want to keep this bike 2up so I am going to go with a brat style seat. Unfortunately, that darn frame dip would hinder anything off the shelf so I have formulated a plan. I believe that with the right fiberglass work, I can make a seat pan that just covers the rails and the tail hoop (essentially the bottom lip of the pan would be flush with the bottom of the frame rail. I can also use this fiberglass to make a smooth transition from the front of the seat to the tank, leaving no "afterthought" gap as I like to call it.

See the pic below. I used a piece of tape to make a line that I like.



So my plan is to use the Dime City Cycles universal mounting plate in the middle of the frame dip to compensate for the dip, then I will simply tape everything off and fiberglass around it to hopefully have a flat seat mount. I know that the brat style traditionally has the seat mounted on the frame, but that just won't work, so I figure that having about an inch of color matched fiberglass around the bottom of the seat will be nice, and maybe a little different than the normal styles.

More to come folks, suggestions and criticism are ALWAYS welcome in this thread. I'm here to learn.

Take care everyone.

Looks like a decent start. THe maxims have good motors, but the tank and the swoopy wheels haven't aged well.


Be careful with the brat tail hoop. A lot of folks keep the hoop flat and as a result the rear wheel hits things at full compression.
Some folks here have used a better solution with a rear hoop that's got a slight kick up to ensure clearance.
It shouldn't really affect the top of the seat, and you can have the lines you want and actual function too.


Welcome to the site!
Lots of excellent info to be found via the search function, and lots of opinions as well.


Be aware that a lot of us are firmly in the function over form camp.
IT doesn't really matter how pretty it is if it can't function safely as an actual motorcycle.
We can sometimes get a bit preachy on this, but we really don't like to see folks build something that is unsafe.


That said, it's your bike. THe only person you have to make happy with it is YOU.

Thanks for the response and suggestions sir.

You are absolutely correct about the tank and wheels. Unfortunately there doesn't seem to be a lot of options for the wheels that I know of. I may change them down the line, but I really just want a fresh, fun, reliable bike to ride when it gets warm so that I can get a little crazy with my other build.

I definitely planned on an upswept tail hoop. Unfortunately my rear frame width is 9 inches from OD to OD, so SonicWorx's hoops may not work for me since they are 8 inches from OD to OD. I've inquired about a custom one, but we'll see what he says. I do not have a pipe/tube bender, and I don't really care to buy one.

I too am for function over form...though I sure like form too. That's why I opted to worry about the safety/engine issues first. It's a great feeling knowing those are sorted out and I can move forward.

Shot glasses are always required in a build.

You aren't kidding. Especially on a first build that I'm doing with no help (other than from you fine folks).

That said, if any of you of you Pittsburgh peoples want to stop by sometime with some insight and an extra hand, I'll be happy to provide the booze. The catch? We have to hang out in my basement until it's warm enough to work in the backyard.

Depending on how much you want to spend and what you want to end up with, you might be able to change out the wheels. I know the 750 Seca rear wheel will fit (larger, skinnier) and some of the Virago units may fit too. Not sure if the XJ650 Turbo Seca wheels will mount straight up as the Turbo Seca's forks do not have the leading axle. I do know that Len (Chacal) on the XJ site has a whole write-up on wheels. Also - the 750 Seca tank/seat should be a direct bolt-on but may not look any better for your purposes.

You know, I haven't really considered changing the wheels yet. I really like the look of the rear to front wheel conversion on a lot of the virago builds, but that still leaves me with a swirly wheel.

I sure hope that the discrepancy between my current smaller fatter rear and skinny tall front doesn't make the bike look awkward, because I do like a fatter rear tire. What do you guys think?

I figure I'll get the bike "complete" and then worry about the wheels in the spring, but thanks for the heads up on the Wheel Write Up over at XJ, I had never seen it before.

As I had said earlier, XJbikes has been great, but when it comes to modifications that stray from the original Maxim/Seca style, I believe this is the place to be.

Cheers.

FWIW - the '83 750 Maxim had a single round headlight, dual round gauges with chrome backs, round turn signals and conventional chrome handlebars. Still has the swirly wheels and "flying apostrophe" bodywork but looks much better to me.

Hah, flying apostrophe! You nailed it with that one. I've had the tank for sale for quite sometime now. I can't really blame anyone for not buying it...but I haven't given up yet.

I agree with you on all accounts, which is why I will use the cheap DCC gauges. I've already taken care of the headlight/turn signals.

NMF said:

You know, I haven't really considered changing the wheels yet. I really like the look of the rear to front wheel conversion on a lot of the virago builds, but that still leaves me with a swirly wheel.

Click to expand...

Others here have converted their Virago aluminum swirly wheels to spokes by using the appropriate Virago hubs, spoke kits, and alloy wheels of whatever size is desired (see 750 Virago build by Nuckingfuts - he had Buchanans lace up 17x3.5 Excel wheels to Virago hubs). If the Virago hubs fit the 750 Maxim then you can go that way too.

Edit - a quick search at XJ Bikes' Modifications area:
From MiGhost - "All 700/750/1000 viragos use the common XJ/XV final drive. The easiest way for a bolt in swap to spokes is to use the 700/750/1000 Virago hubs."

Thanks for the suggestions Zap, those hubs will definitely be on my radar from here on out.

Welcome. I'll be watching closely. That was my first bike - and for all its (considerable)aesthetic shortcomings, it was a strong runner and dead reliable.

Looking forward to seeing where this goes.

Buzz,

The bike sat for quite some time before it came into my hands, and even then it ran alright. After going through the motor and sorting out all of the bugs, it runs even better! Granted, the pods and exhaust will require rejetting but I've seen enough folks with XJ's do similar setups and get them running right (With documented numbers), so it shouldn't be an issue. They Vac-Synced very well and there was no low-end bogging. Can't really worry about it until spring anyway.

The holiday season was slow. I managed to finally strip all of the paint off of the tank. I did use some aircraft stripper on the underside but I simply don't like working with the stuff unless absolutely necessary, so I stripped all the paint with a wire wheel. I also trimmed the front fender and shaped it to be a little more round than square, then practiced a little polishing on the engine covers. Not perfect, but I don't need it to be. Anyone have suggestions for filling in the "Yamaha" with something black?

Finally, I'm working on fabbing the rear tank mount, which also requires some lift. I just started welding so I'm just practicing and seeing what kind of mounts I could do that I'm confident will be functional and strong. Light would be good too, but it is not required.

In the next week or so I'll be practicing welds and waiting on my hoop to come in. The rear of the XJ Frame is 9" OD to OD, and it looks like my best option is going to be from SpeedMotoCo, as theirs is 8 & 7/8ths from OD to OD. I can't find anything bigger, and am kind of in a rut, because I don't know if I can stretch the SpeedMotoco hoop to fit. Suggestions are welcome, as I'm really stuck here, and the tank mount and the hoop are the only thing holding me back from making my seat and re-wiring the bike.

Stock Front Fender trimmed and shaped. Needs filed/grinded in a few places to clean it up, and also painted (Either Black, or to match the tank).


Another side shot showing the fender and the stripped tank sitting at the height I'd like it at. Note that the seat will have a fiberglass piece the covers the rear tank opening to keep it clean. Also, the seat will be sitting on the highest point of the frame rail, if that makes any sense (Not in the dip, but at the height of the rear of the frame). My thoughts are that it SHOULD look proper, but I won't really know until I have that fiberglass laid out.






Now, here is the ROUGH start of the tank mount. Some things to note: THESE ARE MY FIRST WELDS. EVER. I will have my technique down pat before I actually make the final mount. The mounts are three pieces of thinner steel square tubing mounted together. Once again, this is my first weld ever, and there are tons of mistakes. I am having a buddy help me with my techniquw and my final mount.





I think that I will have to grind half moon cutouts into the bottom of the mount so that the tubing fits on to the frame for a proper weld. Criticisms, comments, suggestions welcome and encouraged. Thanks for looking.

It's been awhile. I don't have a lot to update on. I've continued to polish all of the removable engine covers and only have the right side shifter cover to go. The rest of the motor will be painted black with VHT once spring comes around. I'll also take a dremil to the fins for some contrast.

Finally picked up a cheapo headlight mount and started to clean up the bars of the stock switches. Blinkers are a necessity for me so I picked up a pretty cheap, minimalist three position switch with two momentary buttons. One will be used for the horn, and the other will probably be unused (I want the kill switch and the starter button next to the ignition under the seat). It doesn't look like there's enough wires for this switch but I guess I'll know when I wire it up.







I opted to buy (from Dime City) the legendary cafe seat mount, which I believed would keep a consistent line with the tank, and negate that "recess" in the frame. (It's not properly mounted here, just mocked up).



My plan is to simply tape along the current line to make a fiberglass seat pan that will follow. Here is my question, DTT: since the seat pan is going to dip below the tank line, is that going to mess up the overall look? My thoughts are no, but I like to hear others' opinions since this is my first rodeo.

For the sake of easy visualization, lets say the bike will be painted yellow with a black leather seat. I wonder, should I completely cover the whole seat pan in black leather, or should I just wrap the foam and color match the bottom line to the tank? See my high tech renditions below, and pardon the huge pics:






Upswept tailhoop and rear tank mount get welded on next weekend, then the seat build begins. I need to order some rear shocks, speedo/tach, and then I can re-wire it up! After that I just need new control lines and then I'll need to do body/paint work once it's warm enough to move the bike outside.

Started mocking up the tail hoop for welding this weekend. It's a little long as is. Being that I'd like to be able to have a passenger, I'm not going to cut it TOO short. I think id like the end to be about two inches past the axle.



A little CAD work for the seat. I think I'm going to bring it in an inch and a half and call it done.





I hope this makes my previous seat posts a little easier to understand. I could a.) make a flat fiberglass seat pan that mimics the current lines of the cardboard (with padding and leather on top), but leaves a large gap between the seat and the recessed part of the frame

Or b.) drape the fiberglass cloth over the sides in a way that it covers the gap (and somehow maintains a good line as it curves up with the rear).

Good thing I've got other things to do, and time until riding season, because I'm not sure what I'm going to do about that part.

What happened to your photos on the last 2 posts?

speedmotoco said:

Shot glasses are always required in a build.

Click to expand...

Haha I always use egg crates but hell whatever you have lying around!

Zap, they seem to work for me! Is anyone not able to see pics?

NMF said:

Zap, they seem to work for me! Is anyone not able to see pics?

Click to expand...

I only see place markers for the photos in your last 2 detailed posts, not the photos themselves. Prior posts look fine.
Edit - there are 3 photos in your first post that also only show up as markers; the ones showing the air box interior "velocity stack", an interim photo, and one with the tank lifted up. Looks like the ones being referenced from the XJBikes site (not the Photobucket site).

Same here