XS750 Restoration, Part 9 -- Cleaning and Miscellany

It's been a while since I've posted the last entry. In that time, I've mostly been cleaning and doing prep work for some upcoming tasks, and finishing up some of the work I've been doing.

First, I received the K&N air filters to replace the Emgo filters that don't work with the Mikuni MK. I carbs. The K&N filters, on the other hand, seem to work perfectly. Of course, I won't know that for a fact until I can fire up the engine, which I can't do until I get my throttle and clutch cables from Motion Pro...but I'm getting ahead of myself :)

I've also spent more time stripping the paint from the tank -- that's a tedious process! I'm starting to understand why so many others on various web forums talk about using aircraft stripper (chemicals) to strip the paint. However, I have a well at my house, and I really don't want paint stripper or dissolved paint in my drinking water (no, I have no intention of dumping the chemicals in my yard, but inevitably, you're going to spill some).

While discussing the tank, I noticed that the gasket on the filler cap was leaking. Since I had to pull the filler cap to strip the tank anyway, I pulled the gasket while the cap was off. It was no wonder the cap was leaking -- the gasket was crumbling to pieces >:( Fortunately, I saw one for sale somewhere on-line...

In addition to prepping the tank for fresh paint, I also got detailed measurements for the clutch cable, throttle cable, and front brake lines. I now have stainless steel braided front brake lines and bleeder banjo bolts on order from SV Racing Parts (Blair's a great guy to work with!), and I've shipped the throttle and clutch cables to Motion Pro to have new cables made to replicate the originals, only about six inches shorter. I'll try to get the drawings of the new brake lines, the throttle cable and the clutch cable added here soon, in the hopes that it may help others with their XS750 projects, too.

Speaking of brake lines, I'm getting low on funds, but I haven't ordered any of the stainless steel banjo bolts that I intended to get to replace the rusted, corroded bolts that were originally installed on the bike. Fortunately, I pulled out a wire brush attachment for my drill that has done a great job cleaning up the bolts. In the photo in this paragraph, you can see the "before" shot...

...a close-up "before" shot...

...and two of the bolts after being cleaned up.

Still to come: crankcase breather filter, brake line install, clutch and throttle cables, and hopefully, painting the tank.

XS750 Restoration, part 8 -- Carbs are Done, Starting the Tank

This is a shot of the o-ring that had me stumped last time, along with the main jet upon which it fits, and the old o-ring, just to show why it was not exactly obvious that this was where the o-ring belonged. <shrug> Whatever. It fits, and the carbs are reassembled.

After I finished cleaning and rebuilding the last carb, I reassembled the carbs on the angle iron that ties them together, adjusted the butterfly valves so that they are more or less in synch, and reconnected the choke lever. Unfortunately, I cannot find the photos I took of the choke assembly when I first started to rebuild the carbs, but I think I reassembled it correctly.

I think...

Once I was satisfied with the carb assembly, I opened up the package containing the Goodridge braided steel fuel line I ordered to replace the old, ugly, plain rubber fuel line that was originally installed on the bike. Cutting the line into the appropriate sized pieces wasn't exactly trivial, at least with the tools I had at hand, but I was able to get it cut eventually, and installed it on the carbs as shown here. This is going to look sweet when it's reinstalled on the bike!

Then, I took a paint stripper disk to the fuel tank. The more I look at it, the less I dislike the blue and white paint that was already on the tank, but...yeah, it's still gotta go :)

I was at O'Reilly's auto the other day, picking up a set of turn signal bulbs for my wife's CB750A, when I found the paint I want to use on the tank. It's a Dupli-Color (tm, probably) two-part paint kit used to create a black-out effect on chrome or other polished metal. The more I thought about it, the more I thought a black-out chrome finish on the tank would look awesome against the black frame and engine already on the bike, so after work tonight, I got started stripping the old paint off the tank. I wonder how the black-out kit would work over "chrome" painted plastic side panels...? Well, I guess I should first paint the tank and make sure I even like that before I start stressing over painting the side panels.

XS750 Restoration, part 7 -- Some Progress!

I've been getting just a bit frustrated working in the garage lately. Parts were breaking, and I was watching the cost of replacements ratchet up while the funds I have to spend fixing up the bike have been dwindling. However, in the couple of days that I've been working in the garage since my last update, I've made some real progress.

First, I got started cleaning and rebuilding the carburetors. For the most part, the carb work was pretty straightforward. The K&L carb rebuild kit that I bought was very complete, and the parts in the kit appear to be very good quality. I was a little perplexed by this, however:

Where, exactly, does the little o-ring go? I looked at the parts diagram at Power Sports Plus, but the only o-ring they show is on the "main nozzle" -- which is about two or three times larger than the o-ring. In the photo above, I've shown the o-ring next to the needle and needle seat to give an idea of the size. In fact, the o-ring is exactly the same size as the needle, making me think it probably should go on the needle somewhere, but 1) there was no o-ring on the needle when I disassembled the carb (and I've cleaned two of the three carbs on the bike as I type this), and 2) the parts diagram doesn't show an o-ring on the needle, so I'm puzzled why K&L would include this in the kit, since I can't find it anywhere. <shrug>

Edit: With the help of the great people over at Yamaha Triples, I finally identified the o-ring. As I believe Sherlock Holmes once commented to Watson, "Once you have eliminated the impossible, then whatever remains, no matter how improbable, must be the answer." There is only one o-ring on the parts diagram. Therefore, there is only one possible o-ring that the tiny little donut in the K&L kit could possibly replace, even though it seems too small. I tried it, and sure enough, the o-ring will stretch to fit over the main nozzle.

I ran into one additional snag, as well: despite claiming to be a fit for XS750's, the Emgo pod filters that I wanted to use have a lip inside the rubber gasket that partially blocks some of the small ports in the intake side of the carb, at least on Mikuni Mk. I carbs that I have on my bike. I tried to cut away some of the lip to open up the airflow to the ports, but I didn't realize that under that lip is a recess that hold the gasket onto the air filter. When I cut away that lip, I cut into that recess, weakening the gasket, and possibly allowing unfiltered air into the carb. I'm still trying to decide if I can engineer a coupler to allow the Emgo filters to fit on my carbs without restricting the air flow to the ports, or if I should just suck it up and spend the extra money on the K&N filters.

Edit: K&N filters are on the way :)

Edit 2: K&N filters have arrived, and are installed. Yes, they are triple the cost of the Emgo filters, but the K&N's don't have a restriction inside the filter that blocks air flow to some of the ports inside the carburetor inlet. If you are reading this while researching pod filters for an XSx50, my advice is to just pony up the extra cash and buy the K&N filters. They're worth it.

However, I did make some progress in the garage tonight. First, the FZR750 front brake perch and master cylinder that I ordered on E-Bay finally arrived today. I fit it on the handlebars, and it not only fits great, but looks good, too. I had to clip the brake switch wires to fit, since the clubman handlebars are much (MUCH!) lower than stock, but that was easy.

Next, I was finally able to get the piston out of the front, left brake caliper. I've been soaking the brake parts in Liquid Wrench, trying to get the old brake fluid and oxidation to break loose, but while I was able to get the piston about an inch out of the calipers, I just couldn't get it all the way out, no matter how hard I tried. Finally, last night, I had an idea. On my wife's bike, I attached a hose from my air compressor to the bleeder valve, and the compressed air blew the piston free. However, I broke my bleeder valves off in the caliper (yes, on both the LH and RH brakes, grrr...)

However, I managed to match up the diameter and pitch of one of the banjo bolts at Lowe's -- it's a metric 8mm x 1.25 bolt -- and bought a couple of new, plain bolts in the same diameter and pitch. Then, holding the head of one of the bolts in a monster Crescent wrench that I own (seriously, it's got to be like 18 inches long!), I drilled a hole lengthwise through the bolt. Then, I used a drill bit that was just slightly smaller than the nozzle on my air compressor to radius the hole in the head of the bolt, screwed the bolt into the caliper, and pressed the nozzle into the bolt. It took a couple of tries, but finally, there was a sound like a gunshot in the garage as the piston broke free of the caliper. Woohoo!

While the inside of the piston looks pretty gnarly, the inside of the caliper is surprisingly clean, as is the outside of the piston. If I can find new pistons that aren't terribly expensive, I'll probably replace them, but if not, I think I can clean these up enough to reuse.

That only leaves the busted bleeder valve in the calipers, and I think I know how to repair them. The passage from the brake cylinder to the bleeder valve is completely blocked (at least on the LH caliper; I haven't checked the RH caliper yet) with dried brake fluid and/or rust. I am currently trying to drill it out with a small drill bit. I have also spent a little time trying to drill out the remains of the bleeder valve. Once that's done, I'll pick up a slightly oversized (9-10mm) thread cutter, and install a plain bolt where the bleeder valve used to be. SV Racing sells banjo bleeders -- banjo bolts with brake bleeders built into them -- for under $20 each. Rather than use a separate bleeder and banjo bolt, I'll just use the banjo bleeders to bleed the front brake lines, and block off the opening where the bleeder valves used to go.

Gotta say...after several days of breaking parts and finding out that components I've spec'd for the bike won't work out of the box, it was nice to make some progress tonight :)

XS750 Restoration, part 6 -- Rusted Parts, Obsolete Parts and an On-line Parts Diagram

My usual source doesn't have the parts diagram for the XS750, so I was pretty happy to find someone else with an on-line parts diagram for the bike: www.powersportsplus.com. 'Course, a lot of the parts are no longer available, sigh...

Edit: Found another parts diagram/cross-reference index at www.benefiscal.co.uk.

This wouldn't be much of an issue, except that I broke the bleeder valve on the right front brake caliper last night. I couldn't even get the remains of the valve out with an easy extractor. Oh, yeah...and the piston is still stuck inside the cylinder. I went to Mike's XS to see how much a new caliper cost, and they were out of stock. There are a couple of calipers available on E-Bay, but I've already replaced the master cylinder with the master cylinder from a Fazer 750 (well...I will once it gets here). I'm ordering new stainless steel brake lines from SV Racing, and now I need new calipers, too?

Which raises a very good question...rather than try to source 35 year old parts for the bike, why don't I just retrofit modern brakes? If I'm wanting to build a naked sport bike from the XS750 frame and engine, wouldn't it just be better to retrofit new parts wherever possible? I'd have to fab up a brake caliper adapter to convert the bolt spacing on the replacement calipers to the spacing on the forks, but that's doable.

However, there's that whole "integrated system of related parts" concept that I figured out a little while ago. I measured the rotor on my DL-650, and it's about half the thickness of the XS750's brake rotor, which means I can't just slap on a pair of Tokico brakes like I have on my DL-650 unless I also replace the rotors, but the rotors have to mount to the carriers, and the carriers have to mount to the hub...

I read a build thread somewhere on-line about a guy who swapped the entire front end from an SV-650 to his XS750 -- wheel, forks, triple-tree, and brakes. He did some research and found that the SV-650 has the same size steering bearings, so it was a direct fit. That might be the best way to go, since it would give me a more modern suspension and brakes that I could actually, you know, find parts for. The down side, however, is that his front wheel had three spokes while the rear had...well, however many the XS750 has (hint: it's more than three, by quite a bit). The bike looked great, except for the mismatched wheels. I really don't like those three spoke wheels Suzuki puts on its bikes (just don't tell my Wee-Strom!).

Maybe I'll just pick up some used calipers on E-Bay after all. It's a lot easier, and I don't really have the tools or the knowledge to fab up a bunch of custom parts right now. Or, I guess I could always try to drill out the bleeder valve in my calipers, get a helicoil kit and repair the threads and install a new bleeder valve. I still need to break the piston loose, though. Maybe some penetrating oil and a hammer might do the trick? I also read about a way to repair rust inside a fuel tank by filling the tank with a solution of baking soda and water, and applying an electric current to reverse the oxidation process...maybe that would work on the brake piston? Okay, maybe as a last ditch effort if the penetrating oil and hammer don't do the trick, so I've got nothing else to lose.

I'll document the process here as it occurs :)

XS750 Restoration, part 5 -- More Miscellaneous Work

USPS' tracking web site tells me that the parts I ordered from Bike Bandit have arrived in Anchorage, AK but they still haven't arrived at my mailbox. So, having a little extra time today, and not having worked on the bike for the last two days, I took some time to take care of a few details I've let slip so far.

For starters, I decided to remove the old, brittle, busted wire protection over the wiring bundle from the left side hand grip and replace it with some spiral wrap I had laying around. I don't know if it was the previous owner, or if Yamaha labeled all of the plastic wire bundle connectors, but whoever it was, I really appreciated it as it made it super easy to put things back the way they were supposed to be after wrapping the bundle.

...and here it is snapped back with the rest of the wires, and routed under the metal stays on the frame.

After wrapping the wire bundle in spiral wrap, I decided to sand one of the side panels down to bare plastic and try painting it with some Krylon Fusion rattle can paint I had on hand. I got about this far with it when I found...

...a crack about an inch to an inch and a half long -- on the far right hand side of this photo. I used some "extreme plastic repair" cement to bond it back together; we'll see if it works. If not...I dunno...maybe I'll have to order some carbon fiber from Aircraft Spruce and Specialty and start making aftermarket side panels? :)

(Edit: Just to be clear, I didn't ever get around to painting anything. The paint on the side panel in the photos is what I was trying to remove.)

Finally, considering how grungy the front brake system looked, I figured I'd better drain and bleed the rear brakes. I picked up a pretty simple brake bleeder kit from NAPA while working on my wife's CB750A, so I connected it up to the rear brake on my XS750.

The concept is pretty simple: slip the hose over the bleeder nipple, crack the bleeder, and start pumping the brake pedal, adding more fluid to the master cylinder as you pump fluid out of the caliper. While it will work if you simply pump the brake (slowly), it does work better if you can close the bleeder valve before you release the brake. Fortunately, on the rear brake, this is no problem, since the caliper is maybe two and a half feet from the brake pedal. I filled the little bottle, held to the muffler by a magnet in the photo, about half-way full before calling it good.

Unlike the front brake, the rear brake seemed to be in pretty good condition. The fluid was definitely darker than the Prestone Synthetic I added, but didn't look too bad.

I almost hate to confess this in print, but...well...I did use an open can of brake fluid this time. I know, I know. When you open a can of brake fluid, water vapor gets in, and your brake performance suffers. However, I have no intention of riding the bike until I bleed the brake system again. I've got stainless steel brake lines marked for the bike, both front and rear, and I also plan to get master cylinder and caliper rebuild kits for both the front and rear brakes. The only reason I even bothered to bleed the brakes at all was to start flushing out any gunk already in there and to find out how neglected the rear brakes were. Since they appeared to be in pretty decent shape, I suspect the previous owner just couldn't get the cover off the front brake master cylinder, and therefore neglected them.

Anyway, that was all the work I got done on the bike this weekend. Hopefully my new parts will be here after work tomorrow, and I can start knocking some of the major items off the to-do list.

XS750 Restoration, part 4 -- Odds and Ends

I didn't get much work done on the Yamaha last night. It was kind of a busy evening, and I'm mostly at a stopping point until parts arrive. However, I still need to order replacement clutch and throttle cables. Motion Pro sells custom cables, but they need detailed specs, including length, cable free play, size, location and shape of all fittings, etc. According to their web site, drawings showing this information, in addition to a textual description, are requested.

Consequently, I spent most of the time measuring and drawing out representations of the clutch and throttle cables on graph paper. I'll post drawings here as soon as I have converted them to an electronic format.

Edit:

This is the drawing and the dimensions of the clutch cable I need to fit the bike with the Clubman handlebars.

...and this is the drawing and dimension of the throttle cable for the bike with Clubmans.

After completing the drawings, I removed functional-but-...well...unaesthetic? :) ...rack from the rear of the bike, which kind of brought home a point that was obvious in hindsight, but that I hadn't really realized before: a motorcycle isn't just a collection of parts bolted together. It's a system of interworking, inter-related parts that work together to produce a functional whole. Well, yeah. Duh! However, when I started this project, I had a rather naive project plan that involved ripping and replacing parts as required to create the vision of the final product that I had in mind.

But it's not that simple.

Consider the rear rack, for example. In my mind, all I had to do was loosen the acorn nuts that hold the rack to the bolt that goes through the rear shocks, remove the mounting arms for the rack, then put the nuts back on the bolts so that the shocks don't fall off while riding. What I didn't consider is that the mounting flange on the arms of the rack is about an eight of an inch thick, and acorn nuts have a maximum depth to which they can be tightened on a bolt. After removing the rack, I had about a sixteenth of an inch between the acorn nut and the shock, meaning I either need to replace the acorn nuts with regular nuts that I can snug up against the shocks (maybe keeping the acorn nuts to lock the regular nuts in place?) or I need to buy some washers that I can use as spacers between the shocks and the acorn nuts.

Another example is replacing the handlebars. In my mind, all I had to do was remove the components from the old handlebars, remove the old handlebars themselves, install the Clubman handlebars, and reinstall the components on the new handlebars. However, the real world being far more complex than the simplistic model I had in my head, I found that the new, lower handlebars caused me to have too much loose clutch and throttle cable, so not only do I need to replace the handlebars as I originally intended, but I have to replace the clutch and throttle cables, too.

In my reading, I have also discovered that the pod air filters that I want to install will necessitate re-jetting the carburetors, since they flow more air. And so on, and so on. Every change to a component on the bike has implications for other components as well, because every component is related to every other component. Like I said, it's obvious in hindsight, but isn't something that had even occurred to me beforehand.

<shrug>

I knew this would be a learning process before I got started, and school is now in session :) That's a good thing. As I commented to a friend once, there is no point in embarking upon some process that is supposed to change you if you intend to come out of the process exactly the same as you went in. I imagine the process of rebuilding this neglected -- but seriously cool -- motorcycle into the vision I have is going to result in some changes us both. I can't wait to see how we both turn out!

XS750 Restoration, part 3 -- Removing the Tank, Carbs and Air Box

It all started with the clutch cable...

After breaking the ball-end on the OEM clutch cable, I decided to see if I could remove it so I could measure it and order a replacement cable. Unfortunately, I couldn't get the clutch cable out unless I first removed the gas tank. Well, okay...I need to repaint the tank anyway, so taking a deep breath, I grabbed my socket wrench and set to work.

There is a single bolt that holds the tank in place, just underneath the seat. Once that bolt is removed, it is simple to lift the rear of the tank to get access to the fuel line (the coil-wrapped hose near my thumb in the photo) and the vacuum line that regulates the flow of fuel from the tank to the carbs (the smaller hose near my finger in the photo). WARNING: when you remove these lines, the petcock will begin to drip gasoline, unless you have replaced the OEM petcock with a manually operated valve that has an "Off" position, like my CB550 had. I resolved this problem by running a piece of 1/4" hose from the outlet on one petcock to the outlet to the other.

Here's the bike, sans tank. I next removed the seat, since 1) the seat pan is rusting to pieces (grrr...I had planned to reuse the pan), 2) the seat needs to have the padding lowered by about ten feet :) and 3) once the extra padding has been removed, it needs new upholstery, too.

This didn't give me warm fuzzies at all. The high-tension wire from the coil to the spark plug on the left-most cylinder was routed between the frame and fuel tank. Am I just paranoid to be concerned about the insulation wearing out between the spark plug wire and the fuel tank?!?! I really wonder if this is the way Yamaha originally routed the cable, or if this was done by a backyard mechanic (like me, lol).

You can see that the wire has already been chafing on the frame enough to wear through the paint on the frame in a couple of places...

This is the wire bundle that goes to the turn-signal/high-beam/horn switch housing on the left handlebar. The wires appear to be in good shape, but the plastic protective sheath is dry, brittle, and cracked open in places. I'll be replacing the sheath with some spiral wrap, which I fortunately have lying around somewhere here in the garage.

The protective sheathing over the throttle cable is worn through, too. I don't know if I would replace the throttle cable for this alone -- I can see an argument going either way -- but the throttle cable is too long, now that I've installed the Clubman handlebars, so I'll order a brand new, shorter cable from Motion Pro.

The rubber hoses that connect the carburetors to the cylinders are starting to crumble around the edges. Fortunately, I found replacements at Mike's XS and Old Bike Barn. Prices at both sites are fairly reasonable, but Mike's was a little cheaper (and they took PayPal), so I bought a set from them.

At this point, I ran into a bit of a dilemma. I don't have the budget to rip and replace all the parts I want on the bike right now, so this build is going to occur in a series of stages, (hopefully!) keeping the bike in running condition between stages. However, if I am going to pull the carbs to clean them, it seems silly not pick up a carb rebuild kit and replace all of the gaskets, o-rings and other parts that deteriorate with age at the same time. Likewise, while I've got the carbs removed, it seems silly not to go ahead and replace the air filter with a pod-type filter, too. On the other hand, pod filters were kind of a low priority. The stock air box works as-is, so I had originally intended to leave it in place for now.

Decisions, decisions...

Finally, I decided to rip the stock air box out while I had access. If I were to keep the stock air box, I would need to replace the air filter anyway, so why waste the money if I really wanted a pod filter? Originally, I intended to go with K&N filters, but they are really pricey compared to some of the alternatives. An equivalent Emgo filter, for example, is only $8 compared to $39.95 for the K&N. Plus, I need three filters, so that's really $24 for Emgo vs. $119.70 for K&N. I'll gladly pay the extra if K&N filters really are better, but I don't want to just throw my money away...I already did that when I bought this bike :D (okay, not really -- it's gonna be a sweet ride when I'm done!) I'll spend some time doing some research, then decide which brand to go with. Until then, I placed Ziploc sandwich bags over the intake ports and the crankcase breather opening, and secured them with copper wire twisted together. Okay, yeah, it's a little hokey, but all of my screw clamps were too big, sigh. They were designed to fit over rubber hoses which fit over the openings; without the rubber hoses, they were too big to clamp down on the Ziploc bags.

At this point, I was pretty much done for the night. Once again, I'm at a stopping point until parts arrived, so I bade the bike sweet dreams, and called it a night.

And no, I didn't even measure the clutch cable that was the reason I started pulling the tank in the first place, lol.