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Progress!!! 1978 GS1000E Restoration/Performance Rebuild

Ladies, Gentlemen, Boys and Girls!

Over the past few weeks, I've had a lot going on at work. Lately, my company has been sending me on a lot of field welding jobs, so I've been going to my union's training center on Saturdays to get some long overdue practice (SMAW, overhead and verticals, challenging if you don't do them all the time). That, combined with home repairs/cleaning, and I haven't had a lot of time to work on the bike and it was driving me nuts. So, yesterday, I made some desperately needed progress and completed the following:

1. Connected the fuel lines to the new petcock and filled the tank with gas, checked for leaks - none found, yay! I love the guzzler petcock - small, clean, and the knob operation works great.
2. Glued on the emblems (didn't use the decals, couldn't get the air bubbles out of them and they looked like crap)
3. Positioned the controls where I wanted them and drilled the indexing holes in the handlebar - I have a jig for this, which worked beautifully
4. Went over the suspension bolts, etc, for tightness
5. Aired-up the tires
6. Started the engine (hasn't run since last summer) - turned on thefuel, let the carb bowls fill, hit the start button and she fired up first crank over (OMG OMG happy happy)
7. Lubed the chain

In essence, the day has arrived - at 9:15AM CST, I took Francine out for the first time on a quick ride around my neighborhood. I had to give myself a pep talk because I was so incredibly nervous (hence taking the bike out early on a Sunday, as my neighborhood is very quiet at this time). This is the first time that I have EVER rode the bike since I bought her in October of 2013. Words simply cannot describe my elation right now - aside from the expected issues associated with the carbs not being dialed-in, the bike performed beautifully. No leaks, no strange noises, no pieces falling off, nada! It is now safe to say that my restoration is 99.9% done!!!

Initial impressions:
1. I was concerned about the Gast fibers and the x3 stock/x3 EBC clutch springs - once I was out on the road, the clutch felt great (no grabbiness, etc) and the trans shifted like butter. All gears are OK with no weird noises.
2. Engine and exhaust sound like pure sex
3. Brakes need to bed themselves in but work well
4. The suspension is firm but comfortable - the seat is friendly to my butt
5. Even though the carbs aren't tuned, the bike pulls like an ffing mule in 1st gear

Things I will need to address:
1. Carb tuning - accelerator pumps are disabled and I have the pilot screws only 2-turns out. At very light throttle, I can hear the carbs sneezing, indicating a lean condition. I'll set the pilot screws at 2.5 to three turns out and see what happens. Once I get this sorted, I will play with the accelerator pump to fix the dead spot when mashing the throttle.
2. Fuel tank and carb bowl vent hoses - I wasn't thinking when I used black PVC hose, which isn't working well with the amount of heat generated near the carbs (getting a bit soft). I ordered some Tygon tubing from McMaster Carr and will install it next week.
3. Slight weep from one of my carbs bowl vent hoses - I may have got some crud in one of the needle/seat assemblies. I'm not worried about it right now, but if it persists, I will check the offending carb's float height (again) and possible replace the needle and clean the seat.
4. Going to install some Motion Pro quick disconnects in the fuel lines to make removing the tank easier.
5. Valve clearance check/adjustment (duh)

Overall, I want to once again thank everyone who provided insight, help, and support during this build. Without the GSresources, this build would not have been possible. As I venture forth in the carb tuning process, I welcome any suggestions or input that you may have. I am in a state of euphoria right now :welcoming:

Some photos for your enjoyment:





 
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Wow, what a incredible motorcycle! The attention to detail is amazing! Do you plan on showing it? Mid-Ohio Motorcycle Days in July perhaps? I know it would take first place! Plus I'd love to see it in person. Very nice motorcycle indeed 👍
 
Philo, all your effort, time and money have been worth it. She is a beauty.
Is the new suspension keeping up the new power?
 
Philo, all your effort, time and money have been worth it. She is a beauty.
Is the new suspension keeping up the new power?

Not sure yet - didn't really ride the bike long/hard enough to find out. I purposely re-sprung the front forks (also added 10w oil) and rear shock a bit firmer to keep the bike from being mushy under power. I need to get it out on the road and thrash it a bit.
 
Wow, what a incredible motorcycle! The attention to detail is amazing! Do you plan on showing it? Mid-Ohio Motorcycle Days in July perhaps? I know it would take first place! Plus I'd love to see it in person. Very nice motorcycle indeed 

Thanks storm - I don't know about showing it quite yet, however, it's something to think about :-)
 
Looks good, I know it's a relief when you make it back home on the first ride.
Thanks again for the input on how to replate all my bolts/nuts/spacers....
 
Absolutely luv it, amazing work. Your attention to detail really brings out the true lines and look of the bike. Outstanding job.
 
Thanks again for all of the replies - random question: does anybody know if the stock needles in the RS carbs are viton tipped?
 
An amazing restoration. Congratulations on your hard work, attention to detail and beautiful bike!

Cheers!
K
 
It was such a pleasure to sit back and watch this restoration. Not only did you document it, but with detail and excellent photos too. Much appreciated. Now go have some fun on that thing!
 
According to this chart from Jetsrus they are metal tipped not viton.
https://www.jetsrus.com/needle_valv...eedle_valve_and_float_bowl_gasket_mikuni.html
About half-way down the page.

Thanks Steve - the plan for this weekend is to pull the carbs, check all the float heights, check the needles/seats for gunk, and re-enable the accelerator pumps.

I'm debating replacing the needles with viton-tipped ones, as I have access to an entire assortment of them in different sizes/lengths.
 
Well, I think I just made my first minor mis-step - I have my pilot fuel screws set at 2 turns out. According to the documentation on the RS series from Mikuni, the adjustment range is from 1/4 to 1/2 turn, no more.

See page 2 or 5
http://www.mikuni.com/pdf/rs_app_parts_lists.pdf

Without thinking, I have been looking at the HS40 tuning manual from Mikuni, which outlines general tuning procedures for their carburetors. The adjustment range for the HS40 is 1/4 to 3 1/2 turns. Stupid me...

When I pull the carbs this week, I will reset the screws to 1/2 turn and see how she idles. If she still runs lean I may have to up the size of the pilot jet from a 17.5 to a 20

Derp...
 
Update, 5/27

Installed a #20 pilot jet and set the pilot fuel screw to 1/4 turn. Checked all of the float heights and set them to a hair under 18mm (spec is 17mm +-1mm) Enabled the accelerator pumps and have them coming on at just over 1/4 throttle and ending at 3/4 throttle. Replaced all of the bowl vent lines and fuel tank drip line to Tygon. Added a pair of Motion Pro quick disconnects to the fuel lines for ease of removing the tank. While I was setting the float heights, I cleaned the needles and seats really well - I'm happy to report that I no longer have any weeping through my bowl vent hoses.

Took the bike out for a 10mi ride today and all I can say is WHOA!!!! Had her up to around 55 going through some industrial parks and around town. 1st and 2nd gear roar, and my butt can barely stay planted in the seat when I nail the throttle. The sneezing through the carbs that I described in my earlier post is 90% gone, and the #20 pilot jet helped immensely - I am going to open the pilot fuel screws an 1/8 turn and see what happens, hoping to eliminate the sneezing completely. After I test this, I tweak the accelerator pumps a but and have them come on a tad sooner and see what effect it has on the throttle response. I have a sneaky feeling I may need to raise the needles by one slot, but I am going to leave this for last, as I am more concerned with the pilot system and performing a vacuum sync first. Can't wait to take her for another spin tomorrow!


 
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