1977 GS750B - my long awaited first bike!

[Chuck78]

I had an hour tonight to finish what I started on the left bracket the other night, and here it is, looking like it was intended for this bike from the factory! I spent a good amount of time delicately grinding and filing the weld down and making sure the two fork mounting locations were flat and true. Two more to go (one for the 310mm single disc on the GS550)

[Chuck78]

Cleaned it up some, bevelled all the edges for better paint adhesion and shaving a few grams, ground off the raised thread support areas on the backside of the unused threaded holes and drilled out the unused threads for a cleaner look, as well as adding another hole in the center to break up the space uniformly and shave more weight

[Chuck78]

progress!

Well my buddy and I laced up our 2.50 rims on to our OEM hubs, tensioned & trued our eBay score former drag race bike rear wheels with 3.50 rims & oem hubs, and muscled on the Shinko SR 741 and 230 tourmaster tires diy! I painted my modified twin pot caliper brackets, my machinist buddy got my top hat shaped rotor adapters for the CBR 900 RR Fireblade rotors finished and the rotors are installed along with a 1990 GSX1150 front rotor as my rear rotor. CANNOT WAIT TO RIDE THIS THING!!!!

[Chuck78]

I got a Tarozzi Fork Brace as an early birthday present, as well as a gold 530 Hayabusa grade RK O-Ring chain, so I can install my GS1100E alloy swingarm as soon as I get some 530 sprockets! The Wife told me to order whatever shocks I wanted on her bank card because she didn't understand all the answers I gave her to the questions from Hagon/DaveQuinnMC. Dave Quinn Motorcycles told her "are you sure you want the adjustable Hagon 2810? That's a lot of money for a shock that isn't rebuildable. Adjustable dampening is harder to find in the $200-400 price range! So I looked into Works Performance and Ikon Shocks. The Ikon offering (7610?) is rebuildable and offers adjustable rebound dampening settings, whereas the Hagon 2810 offers one more click of dampening adjustment and is $309 vs $380(?) but is not rebuildable.

Also did the quick turn throttle mod I read in a recent thread here using a 7mm or so wide section of SCH40 PVC pipe stretched/snapped into place on throttle tube/grip. I vee'd mine out in a progressive ramp shape so it was still close to stock twist ratio off idle, but by 40% throttle, it is a very rapid twist action. This will also help with 65mph cruising in relation to wrist twisting effort, but still give you really quick wide open throttle when you want it!

[Chuck78]

Another score was a MAC GS750 4 into 1 header at the junkyard today for dirt cheap out of one of their bargain bins outside in the yard. a few rust spots, but my "non- 77 GS750" MAC that I just torched and bent to fit better - it is 90% rust 10% flaking off paint, and has two dents on the bottom, and was off a taller engine like 80+ GS750 or any GS1000/1100. This one looked the same but the muffler exit is at a better angle for my bike, and it is much cleaner and 95% good paint 5% rust and NO DENTS TO FIX!!!! Muffler will be tucked in under footpeg/exhaust mount frame instead of protruding out the side a lot and collector and muffler hanging WAAAAYYYYY TOO LOW like the non-fitting one fit to my bike

[Chuck78]

progress!

Crunch time for our West Virginia road trip! Took me forever to tear down and meticulously clean the Kawasaki Ninja calipers that had been on the shelf in the junkyard parts bins for years. so much crud on both sides of the outer seals, pistons stuck from dirt and varnish, the whole entire seal grooves lined with glued on dried up brake fluid varnish crap... dental pick, can of silicone lube, toothbrush, brass wire brush, and lots of brake cleaner. 3+ hours later:




Got the GS750 primary springs swapped out of the 750 single disc forks and into the dual disc GS650 forks, got the damper rods drilled and chamfered/deburred (another VERY TIME CONSUMING VENTURE, filing out all the burrs on the internal side of the holes for an hour after 15 minutes of marking and drilling), MikesXS Cartridge Emulators installed at 2-1/4 turns compression dampening preload, Lucas 15W fork oil installed.

[Chuck78]

That's really all there is, two main orifices at the bottom of the damper rod for compression and rebound both! If tearing apart your forks, the "DU" rings are the bushings between the uppers and lowers, one under the fork seal tightly fit into the lowers, and one snapped around a recess on the bottoms of the uppers. There's a teflon/nylon seal on the damper rod also. Mine were all in top shape, I was very surprised.

I got mine apart before reading the service manual, turns out I was real lucky. Leave spring in, and use an impact wrench with an allen extension to remove the damper rods to minimize the chances of the damper rod spinning once broken loose, which would require the special Suzuki tool insert on ratchet extensions to hold the damper rod in place while unthreading. I took mine out with a swift crank on the allen wrench with no springs in, and it came right out after the sound of loctite breaking loose.

Reinstalling, it said use some sort of Suzuki bonding agent on the first two threads and blue loctite on the rest of the damper rod allen bolts. I used Select Unyte plumber's pipe joint dope (rated for natural gas, diesel, gas, etc) on the first two threads, as it seemed this was to seal it from any seepage past the copper crush washers and bolt threads.



The copper colored piece is the upper du ring that presses tightly into the tops of the lowers just under the fork seals. the grey piece under it is the lower DU ring with the teflon coated side exposed. the copper piece and the fork seal and the washer just fell to the bottom, they slide around on the uppers. the grey DU ring is snapped into a groove and the anti-friction side is facing out. there are two auxiliary holes under the top out spring on the damper rod, but the two main dampening holes are near the bottom where the damper rod sits into an "oil lock" - an aluminium socket shaped piece that the damper rod seats into.

[Chuck78]

Bottom end of the damper rod, mods to drill out orifices to freely flow oil to allow the emulator to do the dampening. measure up 10mm and drill two opposing holes 90 degrees out from the original holes, then 10mm more on center and drill two more holes 10mm diameter 90 degrees more out, so they are in line with the original holes. All of them get drilled to 10mm (originals are 8mm) and chamfered (beveled) and meticulously deburred with something like a tiny chainsaw sharpening file or an attachment for a dremel. the inside is very tough to deburr. I chamferred the holes in the drill press with a much larger bit to give them a nice countersunk taper, and then started deburring for an hour.

The oil lock is the aluminium piece in the middle of the photo in the last post, although it is sitting next to the opposite end of the damper rod (top out spring and nylon seal end - the top/emulator side) that inserts into it. The tapered end of the damper rod with the 8mm orifices seats into the oil lock at the bottom of the fork.

Also, when disassembling, the 80+ models upper DU ring must be slide hammered out using the fork legs themselves as a slide hammer. compress and then WHAM! slide out rapidly 2 or three times until the ring pops out.

I had a 36mm i.d. piece of cromoly tubing laying around luckily, which was perfect to tap the DU rings and fork seals back in place. Make sure you have something lined up for this task. 38mm for the bigger bikes.

[Chuck78]

EMULATORS, STIFFER 46lbs/in MODIFIED '77 GS750 SPRINGS (ditched the tightly would progressive section) WITH 135mmx25.4mm THICK-WALL ALUMINIUM (includes 14mm of preload) SPACERS (bicycle seatposts), AND TAROZZI #0040 58mmx175mm FORK BRACE IN PLACE!!!! WOOOOHOOO!!!!!!!!!!

Now I gotta get those calipers back together this afternoon before i visit with my lifetime motivation, my gearhead parents, for an early mother's day! Silicone lube vs silicone based Permatex caliper parts lube for the pistons??? Hmmm...



My wife tried to order Hagon 2810 adjustable shocks from Dave Quinn Motorcycles for my upcoming birthday, and he said "why are you spending $300 on non-rebuildable shocks?" I wanted adjustable dampening. Sounds like the $380 Ikon's may be the best bet, may hold off til after more house remodelling to get those. She told me "sorry for the not surprise, but you'll to call Dave myself, as he had lots of questions that I didn't know the answer to as far as rates, valving, riding style, etc."

[Chuck78]

This Permatex Ultra Disc Brake Caliper Lube is AWESOME for assembling calipers. It's brake fluid compatible, super sticky and slick, and can be used on the pistons and seals during assembly - MUCH PREFERRED over the standard method of just wiping some brake fluid on them to slide in. Formulated for sliding pins and pad backing plate contact areas as well, where the super sticky property really helps it stay there for some time to come.

[Chuck78]

Got it this far yesterday! unknown fender was the lightest "shorty" fender of greater width than stock GS fenders that I could find at the junkyard in the $5 bin, have to extend the mounting area a little and remove the front tabs for the brake lines or move them to the rear. May black it out after mods if I have to weld on it.

My buddy fit the same tires and wheel sizes to his KZ and said the 110/90-18 is much larger than the stock 90/90/19 or 3.25x19, and didn't clear due to the tire width and rolled lip on the inside of the fender.

Going for the flat "drag bars" handlebars, hope a 6 day road trip doesn't make me regret going lower on the bars! The GS650GT top triple clamp has a taller riser where the bars clamp (to clear the air valves on the fork leg caps), so that knocks 3/4" off off of the drop from Superbike rise bars to flat. The triple clamp also has a mount for the ignition switch since my GS750 has the switch built into the gauge console (anticipating swapping to the GS400X small individual pod gauges). Every time I ride on the highways or long straight roads, I always always want to get lower and lower, so this was the easy $5 solution. I also swapped on my wife's ripped GS550 seat with some vinyl tape for the meantime, as it is flat and my seat had a rise to the back. This allows me to slide back further to get my body lower and more aero on the highway. We put an unknown smaller seat that only has a 1974 date stamp on it onto hers, and it looks AWESOME. Ditched the trunk, tucked the fender,moved the taillight. Bike is lowered to fit her as she is 5'4" with short legs, and looks AWESOME as is! Reshaping and recovering my seat in the future.

[Chuck78]

WOW, I was soooo happy with my wider rims & super sticky Shinko tires, emulators, fork spring upgrades, & new twinpot dual discs, & drag bars (flat handlebars) on their maiden voyage for 1200 miles through West Virginia twisties! I do, however, think I want either more than 2-1/4 turns on the emulators' compression dampening, or possibly slightly stiffer front springs. Still it was a DRASTIC improvement in handling! I could confidently lean it over pretty darn far in turns, & powerfully accelerate out of mountain turns from a hard 45 degree lean angle - I WAS VERY IMPRESSED. I was ecstatic with the handling, as was my buddy who did the same rims/tires and similar fork spring chops. His words "It took me a while of pushing and pushing the limit to fully realize just how good these tires are!" And they only cost us $126 shipped plus buying tire irons and talc powder, plus computer balancing by our friends at the local VJMC junkyard. Phenomenal improvement. Wow. Pictures to come, new phone USB connection issues to figure out.

[Chuck78]

Here's the GS550 after a lot of lowering mods & cosmetic/styling changes and some unknown seat only marked "April 1974" modified to fit the GS. Shifting has gone south by the end of the WV trip, so the original GS550 engine on the shelf is going to get torn down, gearbox gone through, & case modified to accept the gs650 cylinders! That's a 3.00x16" H-D rim laced up to the GS rear drum hub as I was informed... She's 5'4" with short legs, so we are keeping it a 16 to help her reach the ground flatfooted (rim is rusty and bent and spokes are seized, so maybe an Excel and S.S. spokes soon however, same sizes). It took lowering the bike 1.5" at that just to get her reaching confortably. Drag bars are going to go on this bike as well, a single twinpot brake and massive 310mm front CBR1100XX or VFR800 or something floating rotor that I have.

Taillight has been modified/relocated since this picture

[ron bayless]

I dont see how you guys know how to do all this stuff.Amazing.

[Chuck78]

On top of Spruce Knob in West Virginia this past Tuesday, my 35th bday! HiTemp engine paint DOES NOT work for exhausts, btw... Just painted it before the trip