1978 GS750 - Brat Tracker, First Bike

Re: 1978 GS750 - Brat style, first bike

I am using a marine battery so it is sealed. I haven't had any problems with it and can spray it off if it gets dirty without worry. As for my exhaust, I am using a modified stock 4 to 2 exhaust.

Click on the link in my signature for my build thread and it will tell you all about it.

Re: 1978 GS750 - Brat style, first bike

Don't know how I missed this build till now but glad to see another GS750 on DTT! If you still have the front fender for the bike you can drill out the rivets and pull the brace off for your front forks then fiberglass a new fender. It drops some weight and you can trim it down a little to make it look clean, using the original brace keeps the fork stability.

Re: 1978 GS750 - Brat style, first bike

wership said:

nice... i do like that tank a lot...
ive not seen those lines on a bike before, the swapped tank must sit a lot higher on the frame to create that gap?
your gs is nice... im thankful for the pic of the electrics stuffed in... i was trying to imagine it in my head...

Click to expand...

What I've done is lowered the front tank mounts and will be raising the rear one so that the tank is parallel with the frame. I'm actually going to weld on a bracket and studs where the rear rubber pad is to mount it there, then I will cut off the tabs on the rear of the tank. I just have to work up the guts to complete it.

Re: 1978 GS750 - Brat style, first bike

adjusted the valves
took off the gauge cluster and had to work out a couple wiring issues - problems with the POs wiring job and securing all the grounds
i got a 1.9" speedo from dime city... i tried to bend the bracket so that it would sit better but ended up sheering it off in the vise... so im in the process of making a bracket... ive been zip tying the speedo to other cables to find a good spot for it... i think im going to use the left cluster mount, but i was thinking of putting it lower on the outside of the right fork... we'll see

heres pics of profile and bars... its getting closer
its a lot smoother since i adjusted the valves
still to go:
- rear loop and seat
- headlight
- i bought a one piece stainless brake line for the front, but now im thinking id like to swap out the brake lever & reservoir to slim things down more... so i may wait on installing that
- exhaust

Re: 1978 GS750 - Brat style, first bike

mounted the speedo on the right for now... mostly because i wanted to take up some of the slack in the line
tied the electrical into the headlight low beam... not sure what a better place to do that... i didnt want the light to run on the speedo at all times from the ignition but now that i type this, i realize i run the light all the time for safety so i maybe should have tied the speedo light into the ignition... i think thats how it is into the stock gauge cluster

Re: 1978 GS750 - Brat style, first bike

ive got an oil leak... there is fresh oil on the left, front corner of the cylinder head, but i havent been able to locate where its from... there is nothing leaking from the valve cover (just replaced the gaskets)
there is a lot of oil around the first and second exhaust tubes
my next step is to torque the head bolts and scrub it to see if that solves anything...

the tach hole looks dirty... im going to cut my tach cable apart and use the fitting by filling it with hi temp sealant and screwing it back in

any other ideas for the sources? would this come out of the exhaust? if so, does that mean rings are bad?
hopefully its not that serious... its mostly annoying because the bottom 8" or so of my pant legs are spittled with oil... so i only wear dark pants on days i ride to work...

Re: 1978 GS750 - Brat style, first bike

Tach cables on any of the old GS series bikes have been a notorious oil leak, my 750 always has even with new seals. If you cannot see any oil coming externally pull the header off the cylinder where it looks like it is coming from and check for any oil in the port or exhaust. If so it could be a bad ring or valve guide, hopefully it's not coming from either of the two.

Re: 1978 GS750 - Brat style, first bike

i decided that i needed some time in the garage...
i want to get into the loop and seat but that means ill be out of riding for a while and it was 70 degrees today in my part of ca, so...
i looked at my bike and thought, what could I do?
i took off the tail light and fender, inner wheel well, and turn signals...
i wasnt brave enough to cut off the frame ends just yet...






so i made a template with the seat down, to cover that portion of the seat in order to hide but also have a place to attach the cat eye tail light, plate, and signals
then i cut it out of metal, and bent and drilled it and test fit it...
it needs a lot of help (and probably a new version) but it might just give me an approximation of the look without a whole lot of down time...









the license plate is just too wide to fit between the frame rails so it wont sit flat against the cross piece, but hopefully you get the idea... i think if i cut the rails, grind some on the plate, and paint it black, it will blend is nicely and give me a slightly bobbed back end...
this is one of my first attempts at fabricating... baby steps





ill probably trim the back of the plate holder and bend it up a little more to avoid when the rear suspension compresses and the tire possibly bending the plate...
and as im looking at this, i should have added an inch to the bottom of this piece so that when i do cut the rails, I can trace them and cover the open ends with the piece, that would lower my turns as well, making it easier to clear hte seat and not having to be such large "ears"... and it would also allow me to take the ears from the inside (material behind the license plate which will get trimmed anyway for "weight") and hide the posts and wires from the turns better...
man v.2 is already in the works...like i said, baby steps...





and then when i went to take this last picture, i realized the rubber boot for tail light bulb hits the seat, so ill have to move it down, closer to the plate... good thing i didnt start of v.2 yet... well call it v.2.1

Re: 1978 GS750 - Brat style, first bike

well version one is at least zip tied...
hopefully tomorrow i can go over to a buddies and tack it on...
version 2 will be trimmed on the sides to the width of the frame and then dished out from there (maybe the ol' body hammer and sand in the welding glove trick)... but for now its ok to ride and thats ok by me



i trimmed the ears off the rear cover plate and made a couple double-bended pieces to mount off the former inner plastic wheel well tabs... i was going to use the original tabs that bolted on to the flared end of the frame tubes, but they stuck enough into the wheel well that i thought it might be dangerous/harmful if the suspension compressed enough...
these too will be trimmed, cleaned up and painted black...





tomorrow ill take a whole bike photo to see the effect...




one question: can i lower the angle of the license plate and not fear the rear wheel mangling it? im not really sure how much the suspension can compress...

Re: 1978 GS750 - Brat style, first bike

Looking good Wership. I like the idea of the tail light. I think version 2.1 would look awesome with an arc at the top.
You could also shave a bit of foam off the back of the seat to give it a bit more of a brat look.
Keep up the good work.

Re: 1978 GS750 - Brat style, first bike

Looks nice so far! Really like your sketch on the first page.
If it ends up looking like that youll have a hot looking bike on your hands

Re: 1978 GS750 - Brat style, first bike

thanks guys

version 2 plans:
this shows the depth of the plate "inside" the seat... i need to trim the current version so that it matches the width of the cut frame rails.. im thinking a piece that fills the gap to the radius of the inside of the seat by dishing out so that it matches the curve of the loose vinyl of the seat cover (kind of like an empty clam shell)...
i guess ideally i then weld a piece of round bar to the edge so that its not a sharp edge on the back of the bike... actually i should probably start with the round bar then pound the metal to match that curve from the flat piece that houses the light and plate to the edge of the seat matched to the round bar



ill probably end up wrapping this electrical in a bike tube and zip tying it together with the flap pointed down so that if water gets into the enclosure, it will drain out...
you cant see from here but post #28 with the close up of the turn signal shows that ill have to add a quarter of an inch or so to the bottom to cover the whole frame rail...
in this picture you can see the wires but also the markings to trim and use as the starting point for the outward dishing... basically i would start the bend at the line and move out



this all seems like a lot of work before i eventually put on a loop and brat seat... but i was thinking that i wanted to form some metal before i do something i want to be more permanent so that it looks good in the end... this stuff ive done is pretty rough...

heres what the whole bike looks like currently:

Re: 1978 GS750 - Brat style, first bike

so nothing on the actual bike... the ignition is a little temperamental, which im not sure i understand, there must be something funny in the headlight bucket, where all the wires converge

but i am super stoked on this...
i was lamenting not having a band saw to make clean cuts, and not having the space if i could even afford a decent metal cutting one, so i thought id make a jig saw table...
plans around the world wide interweb seemed big and bulky so i came up with this...





i drilled two holes so i could position it either way (mostly i messed up the first time and it was awkward pushing the metal from the table out... but nice having a large in-feed "table" to rest the material on)
the "boob" like drawing on the plywood below will be two small bearings that keep the blade straight and are bolted to wood that is cantilevered (drawing right of "boobs") from the back of the table to give a larger cutting throat...






to build it:
i grabbed a 3/4" piece of scrap plywood
I drilled a 9/16" hole (1/2" would be ok) where i thought i wanted it, put the jig saw through and then traced the outline of the foot. then i routed out 1/4" deep a little wider and longer than the outline of the jig saw foot... i did 1/4" route for two reasons: first, the front and back of the foot is about 1/4" tall while the sides are about 3/8"; and secondly, it gave me a minimum blade length of 3/4" so i could change the blade and use it to cut 1x material in the future routing it a 16th deeper would probably be safer if im cutting up to 3/4" wood...
then i grabbed two scrap 1x pieces and screwed them in cinching the jig saw in place... im thinking of countersinking four 1/4-20 by 2.5" carriage bolts in the top and using wing nuts to secure it because the screws wont last too long if i keep undoing it...
before i do that i will reroute it in the middle of the scrap piece so there is a long area behind the blade to clamp from and a long area (8" or so) of in-feed space to support whatever material im working with

here are my references:
http://www.instructables.com/id/Inverted-Jigsaw-table/
http://www.brokencitylab.org/blog/tuesday-recap-in-case-you-missed-it-super-jigsaw-rig-graphic-design-in-progress-other-notes/
http://www.instructables.com/id/Portable-tool-work-bench/step1/Jigsaw-table/
http://lumberjocks.com/projects/66601



cutting and trimming the pieces is going to be so much easier now... being able to manipulate the metal rather than using the saw on a clamped piece of metal will allow for more intricate cuts on small pieces. AND it will be way cleaner than the angle grinder i had been cutting the stuff with because my pneumatic sheers only cut to 18 gauge...

now i just need time to make a lot of noise and not wake up my two sons...

Re: 1978 GS750 - Brat style, first bike

version 1 is tacked on for the foreseeable future...
unfortunately i dont have a seat lock so the seat is a little crooked because the left rear rubber mount is too tall








i still need to trim up the turn signal brackets... and then prime and paint it so it doesnt rust...
then its either on to version 2 or a loop and brat seat... depending on how confident i am in making the seat

Re: 1978 GS750 - Brat style, first bike

welded, trimmed, ground, painted (with a couple runs), ready...







tried to use the string to ring down the crooked seat, but it still didnt quite work...

1978 GS750 - Brat style, first bike

Looking forward to seeing more pics. We seem to have a lot of GS's come up on CL around here, so might have to make it my next build.

Re: 1978 GS750 - Brat style, first bike

tried to bend up my seat loop...
soaked the buck, got the tubing red hot and put it around the bend... ended up pushing it against a city bus brake drum below
got a little flat so we'll try it again

problems:
turns out red hot is bad for wood - need to put a piece of thin metal on the circumference
maybe having a 2' section didnt give me enough leverage - ill try a 3' section next
i should have done the sand in the tube trick, but i didnt like the tubing i had because it was too think for the DCC lugs to fit... so i tried it anyway
i have to get 1/8" wall tubing (1" OD and 3/4" ID)

any tips?

Re: 1978 GS750 - Brat style, first bike

Try this.

http://www.youtube.com/watch?v=WOxnN3IaS88

Re: 1978 GS750 - Brat style, first bike

sorry... i cant see what im supposed to try... is that big blank space for a video? can you post the URL instead?

EDITED:
found it on a non-work computer...
you tube video titled "cafe racer rear and hoop bending"

now i just have to find a 6.75" street light

Re: 1978 GS750 - Brat style, first bike

my turns went out... checked and double checked and triple checked the grounding because thats what happened earlier, but it wasnt that... they guys over at gsresources suggested getting a cheap replacement
went to auto zone and found this for less than 4 bucks... its meant for GM cars and trucks i believe and they come on a little slower because its thermal... but it works well...

for now i have it zip tied in, later ill have to figure out a way to attach it more permanently