77 GL1000 Questions


Information and questions on GL1000 Goldwings (1975-1979)
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77RedandWhite
Posts: 11
Joined: Sun May 24, 2020 3:22 pm
Location: York, PA
Motorcycle: 1977 GL1000
1980 CB650

77 GL1000 Questions

Post by 77RedandWhite »



First, my dad and I have been lurking here for several years, since I bought my 77 GL1000 in 6 different colors, barely running on one cylinder, no brakes, and all of the bowls full of varnish "bacon bits". Since then we have rebuilt the engine, the clutch, all the brake parts, painted it, and gone through the carbs an unknown number of times. We did a lot of this with help from this forum, so thank you guys for all of that help.

We have worked our way down the list over the last 5 or 6 years to the last issue- this old girl drinks gas like I drink rum. I'm averaging around 19mpg, and when I have someone riding behind me, I ALWAYS, without fail, get a comment about the smell. So I'm looking for things to check off to see if we can narrow down the cause. I'll list out a few things about the bike to see how many boxes I can check off before we get started:
Important- I have a 77 bike with 76 carbs, or that's what the numbers say.

-Electronic points- original set still running strong!
-Carbs were ultrasonically cleaned, and were cleaned with copious amounts of carb cleaner before and since
-carbs have been rebuilt with randakk parts (for the most part- all of the major gaskets are his)
-"flat spot in throttle" mods (see: randakk) were done and then undone when I felt they weren't helping and gas mileage got worse
-all jets are stock, other than the slow air jet, in the brass elbow- those are currently 120 instead of 115
-the fuel jets are correct; we are aware of the issue in the Clymer manual and have made note of it in the book
-timing has never been out- we have always been very careful to keep it set correctly anytime we do work on the heads
-right head was completely replaced when we found some of the internals wearing out, and it was easier (more cost/time effective) to buy an entire used head than fix the one we had
-plenum has been split and rebuilt with randakk gasket string and orings to the carbs
-strong spark on all 4
-randakk fuel filter
-gas tank has been coated and valve rebuilt (weeps slightly though? will have to take another look someday)
-top coolant pipe orings all got replaced last weekend due to leaks
-large coolant hoses all got replaced and rusted off clips replaced with hose clamps (tested/tightened yearly)
-coolant and oil have been closely monitored over the years due to leaks, neither have ever gone empty
-no oil in the coolant, no coolant in the oil
-compression test was done, i think when we decided to replace the right head, and they all now test over 100, but I don't remember the exact numbers. Lowest might be 115?
-new headgaskets

Issues and Fixes-
-early on, I had a problem with overflowing carbs that filled the cylinders and poured fuel out all over the ground anytime the gas was left on. This was solved by lowering the floats down to 21mm from the LIP of the carbs, instead of being measured from the carb body as it is supposed to be. They could probably be set back about the 3mm up again, since the floats used to be catching on bad gaskets before getting randakk parts involved, and may now be fixed as a side effect of the gaskets.
-air filter has been replaced almost yearly due to rats making nests in it, and last weekend the box got completely cleaned, power wire brushed, cleaned, painted, and has a piece of caging stuck in the front to keep them out for good from now on.


SO... anyone have any thoughts on running rich? The low floats and the over sized air jets should be leaning this thing out, and they don't seem to be doing anything. My pipe tips are SOOTY black. I have not done a recent plug test, and I won't be able to do one until I put the carbs back on and buy some air cut off valve hose- the old seemed to be slightly ripped, would this cause a 100% increase in fuel usage if it was leaking?

Other specific questions:
1. How tight should the orings on the fuel jets be? All of mine have either shrunk or weren't good to begin with, and the two jets held in with the "butterfly" under the bowl are loose (all sets). Could these be leaking extra fuel around the jets?
2. Choke does not engage the throttle until it is fully on- anywhere between 1% and 99.5% it is too much choke with no throttle increase and does not help the bike start. I generally start the bike without playing with the choke, and then warm the bike up "manually" for a minute or two to get it running smoothly (throttle when it tries to quite). Once it warms up it will idle smoothly anywhere between 600-1100 just fine. Ideas? We had an idea to bend the tab so that the choke engages the throttle sooner, but maybe we are missing something else. Idle issues may also be caused by the slow air jet being too big as mentioned.
3. Is there a "recommended" route for the rpm cable? I was putting it behind/through some of the linkage parts and it just doesn't feel totally right.
4. Is there anyone doing carb rebuild/bench testing anymore? Randakk has two guys on his site, but I remember there used to be another one, I want to say in KY area, because I remember pics of his bench engine. And a fourth place that several people mention has also stopped doing carbs. Was thinking about just sending the rack out, now that I can afford to, but I'm not sure who does a full bench test anymore.
5. Does anyone have ideas on replacing the exhaust with straight pipes? I have seen some suggestions of Harley parts, but never part numbers. I'm asking both because of personalizing the bike and because I have seen original mufflers sell for hundreds. Alternatively, I need a header/muffler paint recommendation that won't flake off after a season and easy to do. Or just ship them out for some sort of powder coat...

Thanks for any info you guys can give, and thanks again for all of the help you have given us in the past.
Mike


Naked 77 Wing
80 CB 650, built from boxes of parts
Motorcycles. Snowboarding. Paintball. 3D printing. Cosplay. Warhammer 40k. Tabletop Gaming.
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landisr
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Location: Gilbert, AZ
Motorcycle: 1976 GL1000
1976 GL1000LTD
1994 GL1500A

Re: 77 GL1000 Questions

Post by landisr »

Have you watched what is happening in the plenum chamber while the bike is running? Is any raw gas present anywhere? Have you used a mechanic's mirror to look for excessive gas in the carb throats? How about the slides? Do they all appear to respond to throttle opening the same or close? I'm sure you are aware that they are not directly connected to the throttle cable, and rely on vaccuum alone to raise them... So if they don't travel up & down smoothly, you've got trouble.

Do a search on this site for carb rebuilders. I think you should send the entire assembly so they can check everything except cable routing. They can also check the choke linkage.

There are also posts on here describing how to use Harley Sportster mufflers, which can be found fairly cheap.

Good luck, and keep us posted on your progress. ☝️😁

Ron in AZ
I'm not so sure about an inner child, but I have an inner idiot that surfaces every now and then.. :mrgreen:
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77RedandWhite
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Joined: Sun May 24, 2020 3:22 pm
Location: York, PA
Motorcycle: 1977 GL1000
1980 CB650

Re: 77 GL1000 Questions

Post by 77RedandWhite »

Thanks for the reply.
I have not watched inside, generally if I have it running I'm working on testing something or riding. I will need to order a mirror to look down inside the throats to look for excessive gas. The inside of the plenum is dry though, after replacing the rubber string and orings mentioned.
I cleaned the slides and caps a while back with some 2000 grit and they slide much smoother- no more burs, no more hanging. When I get a mirror I'll be able to make sure they are sliding properly. On the mirror though, where do you suggest looking from? Is looking down through the frame into the plenum and looking sideways into the carbs the only way?

Can anyone weigh in on the fuel jet orings? That's my main concern since finding them loose. Well, that and the cut off tubing possibly leaking.
Naked 77 Wing
80 CB 650, built from boxes of parts
Motorcycles. Snowboarding. Paintball. 3D printing. Cosplay. Warhammer 40k. Tabletop Gaming.
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77RedandWhite
Posts: 11
Joined: Sun May 24, 2020 3:22 pm
Location: York, PA
Motorcycle: 1977 GL1000
1980 CB650

Re: 77 GL1000 Questions

Post by 77RedandWhite »

Just found this, from Ohiobobcat:

I had the same problem at one point. It ended up being a slide sticking in one of the carburetors. I could play with the clutch to slow the engine down far enough that the slide dropped, dropping the idle speed. I was able to see in the intake with a small camera and tell which slide was sticking. I ended pulling the entire set off and used a shopvac to pull air through the runner on each carb while moving the throttle. This showed me which ones were sticking, as well as not moving smoothly. Make sure you empty the fuel from the bowls before you start pulling atomized fuel into the vacuum!

I will definitely try this when I get back to the shop.
Naked 77 Wing
80 CB 650, built from boxes of parts
Motorcycles. Snowboarding. Paintball. 3D printing. Cosplay. Warhammer 40k. Tabletop Gaming.
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landisr
Posts: 787
Joined: Tue Jul 28, 2009 12:18 pm
Location: Gilbert, AZ
Motorcycle: 1976 GL1000
1976 GL1000LTD
1994 GL1500A

Re: 77 GL1000 Questions

Post by landisr »

77RedandWhite wrote: Tue May 26, 2020 2:41 pm Thanks for the reply.
When I get a mirror I'll be able to make sure they are sliding properly. On the mirror though, where do you suggest looking from? Is looking down through the frame into the plenum and looking sideways into the carbs the only way?

Yes, that's the only way I'm aware of...
I'm not so sure about an inner child, but I have an inner idiot that surfaces every now and then.. :mrgreen:
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77RedandWhite
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Joined: Sun May 24, 2020 3:22 pm
Location: York, PA
Motorcycle: 1977 GL1000
1980 CB650

Re: 77 GL1000 Questions

Post by 77RedandWhite »

One problem gets solved... another rears up. One thing we just found is that all of the fuel jets were put in backwards last time. So not only were they not sealed, they were enabling a much higher flow rate through them. So we got those sorted with the new orings on the jets, and it actually runs out of gas now trying to get up the driveway. So we are going to put the fuel floats back up to where they should be, and we were considering changing the slow air jet (in the brass elbow) back out for the stock 115 to allow for slightly more gas- but this should only affect idle right? Not general riding?
We will toss the vacuum gauges back on and sync the carbs as well, just to check them. After that... any more ideas?

Thanks
Mike
Naked 77 Wing
80 CB 650, built from boxes of parts
Motorcycles. Snowboarding. Paintball. 3D printing. Cosplay. Warhammer 40k. Tabletop Gaming.
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ct1500
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Re: 77 GL1000 Questions

Post by ct1500 »

Slow air jet? Lower numbers give more fuel? Are these jets submerged in the fuel of float bowls?
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77RedandWhite
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Joined: Sun May 24, 2020 3:22 pm
Location: York, PA
Motorcycle: 1977 GL1000
1980 CB650

Re: 77 GL1000 Questions

Post by 77RedandWhite »

ct1500 wrote: Wed Jun 03, 2020 4:30 am Slow air jet? Lower numbers give more fuel? Are these jets submerged in the fuel of float bowls?
No, the slow air jets for the idle circuit are a by-pass system. These are in the brass elbow on the side of each carb. The less air that goes through, the more fuel gets sucked on during idle. So the smaller 115's pull slightly more gas at idle than the 120's I had in.
Float levels are back up, and everything appears to be stock. Now the bike seems to have large dead spot from 2.5-6k and then it takes off like a turbo kicked in. Anyone have any thoughts? could this be the slides not opening until 6k? I havent been able to do the vacuum or mirror test yet and will report those findings when I get them.
Naked 77 Wing
80 CB 650, built from boxes of parts
Motorcycles. Snowboarding. Paintball. 3D printing. Cosplay. Warhammer 40k. Tabletop Gaming.
And36y
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Joined: Thu May 28, 2020 2:39 pm
Location: England
Motorcycle: 1977 gl1000 k2

Re: 77 GL1000 Questions

Post by And36y »

How did you get on ?


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