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1979 GS750E did right

27323 Views 111 Replies 21 Participants Last post by  woodsman
so now that I have the GS in my garage, I can finally start ordering the things I need for it. The PO used if for track days, but due to a TBI from an accident (presumably on a different bike...) can no longer ride. My plan is to catch up on basic maintenance for it, do some suspension improvements and get it on the road. I still need to get a safety wire tool to wire everything down once its all assembled again.

As a side note... I know it may be douchey, but I'm seriously considering leaving the number plates on for the street.

Right now I have the following ordered:
-clymer manual
-Progressive front and rear suspension
-rear caliper rebuild kit
-front fork seals
-all balls wheel bearings
-all balls steering stem bearings

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The rear caliper was "sticky" and after taking it apart, one of the pistons was frozen, and the master cylinder had seen better days (there was actually a plastic o-ring lodged in the hole of the banjo bolt... weird). Luckily, the PO had two other rear calipers in various states that he gave me so I took all three and disassembled and cleaned them in order to put together one good one. A grease gun is the absolute easiest way to undo a stuck caliper!

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So right now, I have three serviceable rear calipers, two good pistons, and one good master cylinder. All that's left is for the rebuild kit to arrive and to get it all put together. Later on I'll upgrade the rear to braided lines.

The next issue was the leaky petcock. The PO had switched from a vacuum one to standard, and had made his own bracket for it. After taking the petcock off the tank and cleaning away the paper gasket and rubber cement gasket I found why it was leaking (other than shitty gasket materials).

Seems that there's a dent in the side of the opening that was a little too much for the rubber sealer to handle. In the next couple days I'll sand the area down and hit it with a coat of JB weld to level it all out, then get a strip of rubber to use as a gasket. This ought to do until I get the second tank cleaned out and painted up.
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Here's the petcock assembly... I've added some O-rings to the screws to hold them on for now. When the petcock is attached to the tank, the O-rings will seat in the recesses on the tank (like stock).

Finger Hand

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And at the end of the day (but it still runs with fuel in the carbs):

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ok the hangar should be of a corret design
instead of a slabular 12 gaugw triand shape just splatted on with hotwire
get creative i like 16 gauge cut to the shape needed,but make 2 and leave an extra 1-1/2'' on each one from where i9

t p[lants down on ntailpipe
you got it now edge weld with oxyace

but before hand form the 2 planters to match pip[e
scallop em mspeed hole them
skip weld to tailpipe
or use aluminum or ss and pop rivets
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XB, I have a replacement frame section to weld back on that will return the frame to "stock" configuration.

Also, for those interested in the baffles:









And the old exhaust:





So considering how well the bike ran with the old exhaust, I'd gamble that the new one should perform similarly WITHOUT baffles.

Worst case is I make an endcap with a 60mm opening and baffles/screen
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Rebuilt the clutch actuator and painted the new(er) cover during lunch today.

Old cover:



New:



And installed:



Just need to adjust everything now.
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And we're ready for spring (after I double check all the torque settings and safety wire all the bolts again).


This is the first start since last summer... A bit smokey, but that cleared up after a bit. The paint on the motor still needs to bake though.

I also made a temporary exhaust hanger until I can weld on the replacement hoop/passenger peg mount.



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And we're ready for spring (after I double check all the torque settings and safety wire all the bolts again).


This is the first start since last summer... A bit smokey, but that cleared up after a bit. The paint on the motor still needs to bake though.

I also made a temporary exhaust hanger until I can weld on the replacement hoop/passenger peg mount.



loud eh
a simple end cap with a straight tube same siuze as a header going inside 4'' or so will calm the bark a bit
loud eh
a simple end cap with a straight tube same siuze as a header going inside 4'' or so will calm the bark a bit
Yea so I rode to work today and it's way too loud. I ordered 24" of 3" diameter baffle tube that I'll cut down and weld up to the original endcap (after cutting off the old baffles and enlarging the hole). I have some baffle material coming as well.

The bike does feel really good through the rev range though.

Funny story...
I stopped at a gas station on my way to work and noticed the kickstand was covered in oil. I then saw oil dripping out from behind the sprocket cover. I refueled and assumed that my install of the new countershaft seal had failed so rode back home.
I pulled the sprocket cover off and saw it was still relatively clean under there, no shiny oil slick coming from either the clutch push-rod, shifter rod, or sprocket. It was then that I noticed wetness from the drain hole where the starter was and it clicked. When I deleted the starter, I installed a plug with a breather, but I forgot to install a hose coming off of the breather. A few minutes later I was back on the road NOT recreating the exon valdez disaster.
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So I have the baffles ready to be welded up.

I went with a 1.5" diameter perforated tube, doesn't look like a big difference but it should work pretty well... I can always go up to 2" later. I also went shorter on the length and I won't run an inner cap.





Here's a better look at the difference in diameter. The inside line of the black circle is the outer diameter of the new baffle.







I'll re-use the packing material I have.
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So I have the baffles ready to be welded up.

I went with a 1.5" diameter perforated tube, doesn't look like a big difference but it should work pretty well... I can always go up to 2" later. I also went shorter on the length and I won't run an inner cap.





Here's a better look at the difference in diameter. The inside line of the black circle is the outer diameter of the new baffle.







I'll re-use the packing material I have.
you gotta run a big warsher at the hot end,too much turbulance ,packing will be gone in no time
make the inner warsher cone shaped for a closed end megaphone effect 45 degee or so ie truncated cone
you missed a lathe turning opportunity on the endcap it can aluminum and have a stubby outlet pipe with a nice ball turned end like a yosh can end
something like this but straight
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you gotta run a big warsher at the hot end,too much turbulance ,packing will be gone in no time
make the inner warsher cone shaped for a closed end megaphone effect 45 degee or so ie truncated cone
Thanks for the advice.
I was thinking of a reverse cone
Happy now XB?







Machinist decided to braise it together. Must have been a slow day
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I don't see XB Designs patent pending info stamped on it. You want to be careful I hear some of those Oregon Sheds have big legal departments.
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