1983 GL1100 Strange Vacuum Issues


Information and questions on GL1100 Goldwings (1980-1983)
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Sleepless Art
Posts: 5
Joined: Tue Sep 29, 2020 4:35 pm
Location: Pennsylvania
Motorcycle: 1983 GL1100A Aspencade

1983 GL1100 Strange Vacuum Issues

Post by Sleepless Art »



Thank you for taking the time to read this and I hope someone can assist me here. This is my first post so I will get right down to it.

The Bike: 1983 GL1100A Aspencade 66K mi

The Issue: Cylinders 3 and 4 have a pulsing / crap vacuum. (Gage needle violently sways back and forth) 1 and 2 are perfect (Honestly, this is the only thing that has been perfect on the bike thus far)

The Backstory: The bike for about a 18 months or so in a nice metal pole barn before I bought it 2 months ago. (My first Goldwing. In hindsight should have researched the year better)the bike ran like an asthmatic kitten when I first got it but for its age is in great shape. I am not a pro when it comes to working on bikes but I am mechanically inclined with half a brain to boot. Also reading the how to guides here helped a lot as well. At this point here is all that I have done to the bike to get to where I am now. The carbs have been pulled, rebuilt new injectors, seals, the works. placed them back on the bike, it ran a bit better but now there is a persistent knock at low RPM, Checked spark and compression, Spark: Dead (replaced caps, plugs and wires) Helped some what. Compression: cylinders 1 and 2 100 psi, 3 and 4 65 psi. ( Yeah I know....it hurt me too when I saw it) So I dug deeper. I pulled the heads and deep cleaned them. (Seeing how parts for this model year apparently do no exist any more I had to make due with what I have) Cleaned the valves so they seat correctly again and checked the walls of the cylinders for damage. The walls are beautiful. you can even see the cross hatch marks from the factory. No wall damage to be seen. cleaned all the carbon off the top of the pistons and inspected the original gasket on the heads for signs of leakage, there was none. After cleaning and replacing the heads the new compression stats are now 1. 156psi 2. 132psi 3. 155psi 4. 128psi Not quite up to spec but ill take what I can get. to test things i ride it around the oval road I live on. All in all its about a mile around. The bike stutters and feels sluggish but will move. I will hear a small noise from what sounds like the intake every so often like its gulping for air (I did install a brand new K&N Air filter) I only listed what I did to the motor the brakes were a whole other nightmare.

I have read though some of the posts on here that have mentioned strange vacuum issues but none seem to fit my issue very well. If anyone happens to have any good ideas on what could be causing this please let me know.



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Maz
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Re: 1983 GL1100 Strange Vacuum Issues

Post by Maz »

If the gauges are swinging violently, it is usually due to insufficient damping in the tubes to the gauges. There should be a restricter valve in the tube to each gauge, which you close slowly until the needles stabilise. Apologies if you have already tried this but you don't mention it in your post.

Maz
Ironically, Common Sense is the LEAST common of all senses!

Sleepless Art
Posts: 5
Joined: Tue Sep 29, 2020 4:35 pm
Location: Pennsylvania
Motorcycle: 1983 GL1100A Aspencade

Re: 1983 GL1100 Strange Vacuum Issues

Post by Sleepless Art »

Right, thats what I forgot to include in the post. The gages I have do include adjustment valves. This is the kit that I have and used to do all the testing with. It's not the best but gets the job done.
https://www.amazon.com/gp/product/B00T8 ... UTF8&psc=1

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WingAdmin
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Motorcycle: 2000 GL1500 SE
1982 GL1100A Aspencade (sold)
1989 PC800 (sold)
1998 XV250 Virago (sold)
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2007 Aspen Sentry Trailer

Re: 1983 GL1100 Strange Vacuum Issues

Post by WingAdmin »

I don't use them anymore (I have a set of self-damped vertical manometers), but I found that using a set of aquarium valves in the lines, with a large volume of air behind it (easily done with a length of tubing) damped those vibrations. The idea is to AVERAGE the reading over time, and this is done by having the vacuum gauge measure the amount of vacuum in that volume of air, while allowing the air to move in and out of that volume of air only a tiny bit at a time (through the restricted aquarium valve).

You can see me using this method here: viewtopic.php?f=11&t=81

Sleepless Art
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Joined: Tue Sep 29, 2020 4:35 pm
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Motorcycle: 1983 GL1100A Aspencade

Re: 1983 GL1100 Strange Vacuum Issues

Post by Sleepless Art »

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I took a small video of what's going on with it. I followed your advice but I am still getting the same results.

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WingAdmin
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1982 GL1100A Aspencade (sold)
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2007 Aspen Sentry Trailer

Re: 1983 GL1100 Strange Vacuum Issues

Post by WingAdmin »

Sleepless Art wrote:
Wed Sep 30, 2020 4:23 pm
I took a small video of what's going on with it. I followed your advice but I am still getting the same results.
Are these your valves?


If so, then that's your problem. You need air volume as a buffer in between the valve and the meter. That's why I mention in my article that the valves should be as close to the engine end of the hose as possible, so that you have a length of hose in between the valve and the meter containing air that becomes your buffer.

Insert a foot or two of hose in between the valve and the meter, close down that valve almost all the way, and it should fix your vibrating needle problem.

Sleepless Art
Posts: 5
Joined: Tue Sep 29, 2020 4:35 pm
Location: Pennsylvania
Motorcycle: 1983 GL1100A Aspencade

Re: 1983 GL1100 Strange Vacuum Issues

Post by Sleepless Art »

I can do that. However, I guess what I am most concerned about is why 3 and 4 have no vacuum at all. I changed around all the gages to make sure that the reading was the same on all of them and it's the same every time no matter the gage. The bike is running really rough and I am out of ideas oh how to fix this thing.

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Wilcoy02
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Motorcycle: 1983 GL1100 I purchased 3/16

1983 GL1100I frame with an 80 engine. poor boy installed with C-5 ignition--DIED in Grande Prairie Alberta Canada 8/15


98 valkyrie sold 8/16

Re: 1983 GL1100 Strange Vacuum Issues

Post by Wilcoy02 »

Welcome to the forum from central Ohio.

Brakes are always a nightmare after a bike has sat for a period of time.

Keep us informed of what you find on this.

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WingAdmin
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Joined: Fri Oct 03, 2008 4:16 pm
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1982 GL1100A Aspencade (sold)
1989 PC800 (sold)
1998 XV250 Virago (sold)
2012 Suzuki Burgman 400 (wife's!)
2007 Aspen Sentry Trailer

Re: 1983 GL1100 Strange Vacuum Issues

Post by WingAdmin »

Sleepless Art wrote:
Wed Sep 30, 2020 10:08 pm
I can do that. However, I guess what I am most concerned about is why 3 and 4 have no vacuum at all. I changed around all the gages to make sure that the reading was the same on all of them and it's the same every time no matter the gage. The bike is running really rough and I am out of ideas oh how to fix this thing.
3 and 4 are showing no vacuum, but there is a tiny bit of movement - almost like there is a restriction in the hose. Are those cylinders running? Are the exhaust pipes on those cylinders hot? If so, then the problem is going to be with your gauge setup, not the engine.

I find that a lot of the time, the difference between gauge calibrations can be enough to prevent a perfect carb sync. If you pick one of the gauges that is working fine, and move its hose from cylinder to cylinder, does it show vacuum on all cylinders?

Sleepless Art
Posts: 5
Joined: Tue Sep 29, 2020 4:35 pm
Location: Pennsylvania
Motorcycle: 1983 GL1100A Aspencade

Re: 1983 GL1100 Strange Vacuum Issues

Post by Sleepless Art »

Im sorry if i am not doing a well enough job trying to explain this issue. over the last day or so I did everything you all suggested. larger tubes changing the gages, you name it I tried it. The results are the same. Wild pulsing movements ranging from 50 PSI to 0 PSI in rhythm to the RPM (I should have gotten video) The pipes from the carbs to the head all get hot when I run it. Not super quickly but at what I would say an average rate. They all seem to gain temp at the same rate as well. The bike still stutters when under load and sounds like its missing strokes. I tested the Caps, wires, pulse gen, the whole 9 yards again and everything fell within spec. there is spark going to all 4 plugs.



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