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I'm a newbie with a '82 GL1100A with 18,000 miles. I just picked it up last fall after a 10 year sit in a garage, and did all the recommended stuff such as; change all the fluids, rebuilt the carbs, replaced the timing belts, new rubber, and refurbished the rusted tank. It has been running good and strong (though, I don't have anything to compare it to) until I just changed the plugs for its spring tune up. Now it intermittently seems to lack power and makes a noise like it might be missing on one cylinder. I'm getting ready to try another set of plugs since that was the last thing I did, and was wondering what would the effect be of changing the heat range..... colder verses hotter... etc. Can anyone explain to me what effects a hotter or colder plug has on a gl100 and on performance? Thanks. Jeb
 

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[email protected] wrote:
I'm a newbie with a '82 GL1100A with 18,000 miles. I just picked it up last fall after a 10 year sit in a garage, and did all the recommended stuff such as; change all the fluids, rebuilt the carbs, replaced the timing belts, new rubber, and refurbished the rusted tank. It has been running good and strong (though, I don't have anything to compare it to) until I just changed the plugs for its spring tune up. Now it intermittently seems to lack power and makes a noise like it might be missing on one cylinder. I'm getting ready to try another set of plugs since that was the last thing I did, and was wondering what would the effect be of changing the heat range..... colder verses hotter... etc. Can anyone explain to me what effects a hotter or colder plug has on a gl100 and on performance?
Jeb, the effects of a hotter or colder plug really have no effect on engine performance UNLESS- either case causes plug fouling or pre-ignition. The plug heat range should be kept pretty close to production as engine damage can occur if too hot a range is used, or plug fouling & poor fuel economy if too cold a heat range is used.

Below is a a copy of an article I had on file from one of my old engineering books.


The operating temperature of a spark plug is the actual physical temperature at the tip of the spark plug within the running engine. This is determined by a number of factors, but primarily the actual temperature within the combustion chamber. There is no direct relationship between the actual operating temperature of the spark plug and spark voltage. However the level of torque currently being produced by the engine will strongly influence spark plug operating temperature because the maximum temperature and pressure occurs when the engine is operating near peak torque output (torque and RPM directly determine the power output). The temperature of the insulator responds to the thermal conditions it is exposed to in the combustion chamber but not vice versa. If the tip of the spark plug is too hot it can cause pre-ignition leading to detonation/knocking and damage may occur. If it is too cold, electrically conductive deposits may form on the insulator causing a loss of spark energy or the actual shorting-out of the spark current.


A spark plug is said to be “hot” if it is a better insulator, keeping more heat in the tip of the spark plug. A spark plug is said to be “cold” if it can conduct more heat out of the spark plug tip and lower the tip’s temperature. Whether a spark plug is “hot” or “cold” is known as the heat range of the spark plug. The heat range of a spark plug is typically specified as a number, with some manufacturers using ascending numbers for hotter plugs and some using descending numbers for hotter plugs.

Heat from the combustion chamber escapes through the exhaust gases, the side walls of the cylinder and the spark plug itself. The heat range of a spark plug has only a minute effect on combustion chamber and overall engine temperature. A cold plug will not materially cool down an engines running temperature. Too hot of a plug may indirectly lead to a runaway pre-ignition condition that can increase engine temperature. The primary affect of a “hot” or “cold” plug is to effect the temperature of the tip of the spark plug.

The heat range of a spark plug (i.e. in scientific terms its thermal conductivity characteristics) are affected by the construction of the spark plug: the types of materials used, the length of insulator and the surface area of the plug exposed within the combustion chamber. For normal use, the selection of a spark plug heat range is a balance between keeping the tip hot enough at idle to prevent fouling and cold enough at maximum power to prevent pre-ignition leading to engine knocking.




[suP][suB]Twisty[/suB][/suP]

[suP][suB][/suB][/suP]

[suP][suB][/suB][/suP]
 

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[email protected] wrote:
I'm getting ready to try another set of plugs since that was the last thing I did, and was wondering what would the effect be of changing the heat range..... colder verses hotter... etc. Can anyone explain to me what effects a hotter or colder plug has on a gl100 and on performance? Thanks. Jeb
:waving::waving:Welcome to the Best Goldwing Site on the Internet, Jeb!:waving::waving:

Before you replace the plugs take a look at the ones in the engine. Double check the gap, make sure it's not too wide. Take a look at the color of the plugs if you've run them a bit, black and/or sooty bike's too rich, white and a bit dusty looking it's too lean, light tan and things are hunky dory. If you see signs of too lean or rich, it's time to look at the carbs at least on the cylinder(s) that are showing bad fuel mixtures. Since it's intermittent it doesn't sound like plugs, but that's the first place to take a look since as you say that was your last place worked on. Did you change the fuel filter?
 

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as twisty mentioned, unless you have a bad plug (unlikely unless you broke it putting it in) this could be several things. you might check to see if the ignition wires are well connected, including screwing the cap off the wire and putting it back on, doubt it would be a coil as that would give trouble on two cylinders.

btw nice bike and welcome to the forum
 

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Hi Jeb (im not going to put your email address!) and welcome.

Nice bike by the way

cold plugs cause poor running, a sluggish engine, coking of top end and exhausts

However if your doing a lot of continuous long distance in hot weather riding then fit one grade colder plug to help dissipate the heat from the cylinders. When your trip is over change them back to standard straight away.

hotter plugs are nothing but trouble as the plug overheats rapidly and is unable to dissipate the heat quickly enough so the insulator breaks down and the plug shorts out.

The only time I can see a hot plug being any use is if you normally ride in a hot climate then decide to visit the far north.

The best advice is stick with standard and you can't go wrong.


If the problem only started after changing the plugs, check that they are seated properlyso there are no gas leaks around the compression washer on the plug
 

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Thanks, that helps a lot.I replaced the plugs again, with Iridium ones this time, and things seem to be back to normal, but since this is my first Wing, I'm really not sure how much power it should have. I think I'll tryto find another GL1100 at a dealer somewhere and takeit for a test drive. That way I'll have a baseline for comparison.

It seems like it might be running a little rich and possibly fouling the plugs. After rebuilding the carbs last fall, I've nevertuned the idle mixture screws as per the instructions in the book. I just started lean, and rode for a little bit, then backed them out a quarter turn, rode a little bit more, backed them out a little bit more until it didn't deem lean anymore. The book's instructions say to hook up a tach that is sensitive enough to show changes as little as 50 rpms, but I can't seem to figure out how to hook up a sensitive enough tach. The book doesn't say, and when I tried an inductive one, it just bounced all over the place. Any help here on adjusting the idle mixture screws?
 

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My friend does it with syncing the carbs, I don't know how I've watched him do it a couple of times he has to go back and fourth from left to right and corrects the idle speed, then does it again and again until they all even out,

As far as using The tach hook up, I recommend using a digital testlight, Their pretty cheap at any car place, (checker auto parts, napa, where ever) the only thing is you have to divide the tack reading in half because the coils fire twice every revelution, 1&2 and 3&4 I believe are on the same coil, That works best for me, somepeople say you can hear the difference, I can't,

There are so many different ways, you just gotta find one that works for you,



And for the spark plugs, I usually run the hotter heatrange plug, like if the stock plug is a de-8a I use a de-7a, I use ngk and don't have a problem,But I'm sure the type of plug people use is also up for argument.

Good luck with the wing
 

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Gearhead76 wrote:
My friend does it with syncing the carbs, I don't know how I've watched him do it a couple of times he has to go back and fourth from left to right and corrects the idle speed, then does it again and again until they all even out,

thats how its done back and forth it tells you in the book as far as the tac check out a lawnmower shop the works on 2 cycle motors they should be able to get you one thats where I got mine from
 

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What Twiisty said!:)
 

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Might be stupid to ask but if you don't have the Original plug wires which are 2 molded together so you can't cross them check to see if you crossed your wires?

I ask because you say it feels like 1 cylinder isn't firing !
 

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Thanks, but spark plug wires are labeled and correct.



I'm pretty sure I've narrowed this intermittent problem down to a carburetion problem. One time when the problem was happening I hit a bump and the problem immediately went away. Other times, when it's happening, if I open the throttle completely in first gear and let the bike accelerate to a high enough RPM, the problem goes away.



Now, I've been experimenting with lightly tapping on the carburetors individually with small hammer when I’m experiencing the problem, thinking that one of the vacuum pistons is getting stuck. I've narrowed it down to the bowl on the number 4 carb. If I tap on the top of any of the vacuum chamber covers, there is no effect. If I tap on the float chamber of any of the other carbs, there is no effect. As soon as I tap on the float chamber of number 4 carb, the problem goes away. This is leading me to believe I' m experiencing a stuck float in the number 4 carburetor.... anyone concur?
 
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