78 GS 750 Rebuild

[Sam 78 GS750]

So I got the seat pan and a few other bits powder coated, and dropped the seat off to get a cover made. I love to do everything myself, but I'd rather spend my time wrenching (and hopefully riding soon) than learning how to use a sewing machine lol. Most aftermarket seat covers I found weren't really what I was looking for. The guy's also recreating my foam (which was shot) in memory foam. Hopefully that will mean my wife will be comfy for more than 50 miles...

Also dropped my gas tank off at the local radiator shop to get sealed. For about 100 bucks more than the Caswell kit, they're completely sandblasting inside and out, pressure testing, fixing any pinholes, leaky seams etc., sealing the inside, and re-pressure testing. Well worth it in my opinion.

Technically, I could ride the bike right now. I'd just have nowhere to sit, and would have to hang a milk jug from the handlebars for fuel delivery. It would also be missing quite a few 'street legal' items like a headlight, turn signals, brake light, etc. Oh yeah, and foot pegs. I would have no foot pegs. I could ride it though...

[pete]

Looks like some pretty good progress there Sam, but bugger on the tach cover, hopefully you can get that sorted.

I did the same method on the stock 450 clocks and managed not to break them, but it was an exercise in care and patience for sure.

[Sam 78 GS750]

Also having some fun trying to sort out jetting https://www.thegsresources.com/_foru...o-match-Needes

[Sam 78 GS750]

...and this happened. https://www.thegsresources.com/_foru...e-tach-in-half

20180624_230734 by samL9, on Flickr

[Sam 78 GS750]

that adventure went on over here... --->https://www.thegsresources.com/_foru...-is-super-easy

[Sam 78 GS750]

Also bought a welder and repaired some cracks in the seat pan. Had fun trying to weld tack strips to the seat, and finally got a spot welder which worked perfectly
20180630_112628 by samL9, on Flickr

20180630_112639 by samL9, on Flickr

20180630_112659 by samL9, on Flickr

[Sam 78 GS750]

Cleaned up the carbs a bit. They were the first thing I did, back before the rabbit hole of "while I'm in there" turned replacing a head gasket into a complete resto lol. I had dipped and scrubbed, etc. They were clean and solid, but ugly. I polished the bracket, replaced a couple of screws, zinc plated other bits, and polished the caps and float bowls. Turned out nice.

20180626_011605 by samL9, on Flickr

...in other news, K&N quality control ain't what it used to be. What's wrong with this picture?
20180630_142320 by samL9, on Flickr

[Sam 78 GS750]

Some progress on a few fronts...

I (loosely) wired everything up to test.
20180619_235526 by samL9, on Flickr

20180619_235357 by samL9, on Flickr

20180619_235343 by samL9, on Flickr

20180619_235548 by samL9, on Flickr

20180619_235631 by samL9, on Flickr


Everything works, but I do have a few gauge/indicator bulbs that need to be replaced. If that's the only issue after all the cutting and splicing and soldering I did, I'll definitely call it a win!

[Sam 78 GS750]

In other news, I bent one of the carb needles when I dropped the slide. When I ordered a new one, I figured I should order 4 for consistencies sake. Glad I did, the new needles are much thinner than what's on there now. I recall that the PO told me he replaced the carbs at some point. It's a bit confusing, because it seems there were like 4 different needle/main jet combinations on the 750 between 77 and 79, depending on engine number.

Should I replace the needle jets as well now, to match the thinner needles? I'm pretty good as far as adjusting and synching, but I'm a bit out of my territory here with swapping jets and needles, etc.

[Sam 78 GS750]

Got back from a much needed vacation on Sunday, and had a bunch of parts packages waiting. It was like Christmas!

Got the pipes on yesterday. They look really good. I had a bit more trouble than expected trying to get everything to line up. First time fitting a 4-1... At first I just pushed all the pipes all the way into the collector, but then it was hitting the center stand and the frame in a few places. Figured out that you have to just barely fit them in, and then kind of push them in a little bit one at a time and twist the collector to get it to sit how you need to. Now I know...

20180612_073246 by samL9, on Flickr

[pete]

Bugger on those parts disappearing Sam but as long as those are proper K&N you shouldn't have too much trouble getting the jets right. I did find however on the 450 that the velocity stacks were even easier to tune again over the K&N pods, although to be fair the K&N pods were on the stock carbs that ended up having failing/splitting diaphragms.

Can't help on your jet sizing on the 750 though I'm afraid, don't think my 450 experience will help much there

[Sam 78 GS750]

I gave up on trying to find stock pipes in decent condition and ordered the Delkevic. Seems to be highly regarded. This one here ---> http://www.delkevic.us/index.php?rou...oduct_id=45596

Also gave up on finding an airbox in decent shape, and ordered a set of these ---> https://smile.amazon.com/gp/product/...?ie=UTF8&psc=1 Hopefully the ones on Amazon are legit...they're about $60 cheaper than the K&N website...I have doubts about Amazon and knock offs these days.

So much for not having to bother with carb tuning. I was really hoping to avoid it. My pipes and airbox were in great shape, and before the head gasket leak/stator/etc. situation on my cross country trip, the bike ran like a dream. It's on me though, for leaving my stuff in someone else's care. They were in my brother in law's garage and disappeared...

Oh well... I ordered jets as well. Searched through threads, and it seems most folks with a 750 with pipes and pods end up somewhere between 115 and 120 for the mains, and either stock for the pilot or one size up. I'm thinking if I start at 117.5 mains, one size up on the pilot, and 2 notches down on the needles it should put me in the ballpark for a good starting point (I hope). Any advice in this area would be very welcome.

[pete]

Good stuff Sam, hoping I can do something towards some progress soon too.

[Sam 78 GS750]

Thanks, Pete. Glad to see you over here. I've been following your Kat thread with a lot of interest.

[pete]

Hmmm apparently I hadn't tuned in to your thread Sam, will do now though, some real nice stuff going on in here!