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My bike seems to run like it is starved for fuel. There is fuel seeping from the #1 carb float bowl drain screw. However, the plug reads white, with grey electrodes. The only plug reading light brown is for #4 plug. I've adjusted all pilot screws to spec (idle drop). I sometimes get carb popping. I'm thinking i may have a vacuum leak, or the carb sliders are stuck? Operating temp is normal. I'm only getting 36mpg on the highway. Twisty mentioned in another post that Wing plugs tend to run white.
 

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mag wrote:
My bike seems to run like it is starved for fuel. There is fuel seeping from the #1 carb float bowl drain screw. However, the plug reads white, with grey electrodes. The only plug reading light brown is for #4 plug. I've adjusted all pilot screws to spec (idle drop). I sometimes get carb popping. I'm thinking i may have a vacuum leak, or the carb sliders are stuck? Operating temp is normal. I'm only getting 36mpg on the highway. Twisty mentioned in another post that Wing plugs tend to run white.
Mag, the plugs on the later GoldWings are very white even when correctly jetted & running correctly. Honda used a lean burn combustion chamber & that coupled with the use of modern emission friendly unleaded fuel doesn't lave much on the plug to read.

I can't say for sure what color is normal on that early bike of yours but without leaded fuel you sure won't get much color. That #4 carb sounds a little rich compared to the others, if that is the only carb with vacuum lines running to it make sure those lines aren't sucking in fuel from somewhere. (or possibly a malfunctioning slow air cut-off).. Not sure on your bike but on some of those early bikes there was ONLY an accelerator on the #4 carb, if so look no farther for that cylinder being richer.

The modern fuel available now is formulated for emission control as well as higher compression fuel injected engines so does ignite a little harder than the older fuel.. On my later 1200 Wing I do the proper idle drop to get base settings on the pilots then open each pilot needle another 1/4 turn from that. You could try that or even an additional 1/4 turn yet.. If you see a drop in miles per gallon then you have gone too far.

Have you ohmed out the plug wires & any plug wire resistors? How about power to the ign coils, if there is resistance in the coil supply wiring or ign switch your coil output will be low at peak combustion pressures like throttle roll on or accel.

If you want to try to get a plug color reading drop by your local small airport & ask them to sell you 5 gallons of their lowest octane leaded airplane gasoline, that should give you a little plug color to look at.

Twisty
 

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mag wrote:
My bike seems to run like it is starved for fuel. There is fuel seeping from the #1 carb float bowl drain screw. However, the plug reads white, with grey electrodes. The only plug reading light brown is for #4 plug. I've adjusted all pilot screws to spec (idle drop). I sometimes get carb popping. I'm thinking i may have a vacuum leak, or the carb sliders are stuck? Operating temp is normal. I'm only getting 36mpg on the highway. Twisty mentioned in another post that Wing plugs tend to run white.
Mag, typically you cannot get a good plug reading on a Gold Wing engine unless you do a high RPM/ high load acceleration test to read the plugs.

To do this you warm the engine, then take the bike to a dragstrip or an abandoned road and accelerate the bike under full throttle to the top of third gear then kill the engine, pull in the clutchand coast to a stop and remove the plugs.Typically this methodwill show a distinct difference in plug color.Black means too rich and white means too lean. Alight tan color is just about right. This method will only get full throttle jetting right, but, it will show that main jets are correct, but, there are two other fuel jets in the carb that need to be right also and there is a needle that varies fuel flow through the main jet at part throttle. All need to be in correct order for the carbs to work properly.

Normally, when I work on a poor running Wing engine I find that the plugs are black if the needle valve is sticking open or that the plugs are white if the primary and intermediate jets plugged. Usually the popping through the carb is caused by a lean condition and since the idle and intermediate jets are so extremely small it is very easy for these jets tobecome clogged by dirt or rust from the gas tank. Quite often, when these small jets become clogged the gas mileage drops because you need to give much more throttle opening to get the bike to go becauseonly the main jet is delivering fuel, but, the main jet is not designed for low RPM fuel delivery so it causes the engine to run poorly.

Since your plugs do not readin colorconsistently, carbs are poppingand your gas mileage is poor I would recommend a complete teardown and rebuild of your carbs. It's very delicate and time consuming work, but, if you get a manual and study it along with the help of the guys here you should be able to get those carbs running like new again if nothing is broken inside. Let us know what you decide to do with the carbs so that we can help you with the float adjustments and give you tips as you go along with them.

If you tear them down, be extremely cautious and gentle with the float pins as they only go in and come out one way (tapered pin) and only work on one carb at a time. If this is your first carb teardown down be surprised if you can't find all the jets because some are under aluminum pucks and corrosion can make them very hard to get out sometimes. One last tip, replacethe o rings on the jets even if you think they look OK and lubricate them when you slide them into place. Read the carb section of the manual a couple of times before tearing the carbs apart. These carbs have lots of hidden secrets for the uninitiated, but many first time carb rebuilders have been successful with rebuilding the Gold Wing carbs with a little help from friends here.

Good luck.

Vic
 

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Thanks, guys. These carbs have been rebuilt by Honda, and i checked the float heights, also put in OEM carb-to-plenum fuel seals and a brand new gasket at the air chamber halves. I also cleaned my tank, though i suspect minute rust is making it through. The #1 float seems to hang up, though i'm confused as to why the plug doesn't darken. The symptoms would suggest what Twisty said about jets getting plugged, though the bike does idle well, apart from a slight miss. I put new intake o-rings in, and suspect maybe one got disloged. I'll check for a vaccum leak. There are no accelerator pumps on these bikes, and the air cutoff is brand new. Before doing the above, the carbs leaked fuel externally from the fuel seals and internally at the air chamber. Plugs would also foul up. BTW, Twisty, doesn't turning the pilot screws out lean the mixture???
 

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mag wrote:
Thanks, guys. These carbs have been rebuilt by Honda, and i checked the float heights, also put in OEM carb-to-plenum fuel seals and a brand new gasket at the air chamber halves. I also cleaned my tank, though i suspect minute rust is making it through. The #1 float seems to hang up, though i'm confused as to why the plug doesn't darken. The symptoms would suggest what Twisty said about jets getting plugged, though the bike does idle well, apart from a slight miss. I put new intake o-rings in, and suspect maybe one got disloged. I'll check for a vaccum leak. There are no accelerator pumps on these bikes, and the air cutoff is brand new. Before doing the above, the carbs leaked fuel externally from the fuel seals and internally at the air chamber. Plugs would also foul up. BTW, Twisty, doesn't turning the pilot screws out lean the mixture???
Mag, it takes a pretty over-rich mixture to darken a plug on the GoldWings. If it colors (even under sustained wide open throttle) it is running way rich. Even then all you should see is a faint gray to tan ring (halo) around the porcelain. On my 1200 that I ride every day with most days seeing in excess of 90 MPH for a period the plugs are an off white to light gray with a little darker ring on the tops of theporcelain. Those plugs have been in the engine for slightly over 7,000 miles. Even my Harley (& those are known to run on the rich side) doesn't color the plugs but will leave a very light tannish gray halo on the tops of the porcelain.. The exception here will be a sooty black that will cover the plugs if the engine is allowed to idle while cold, but that should burn off easily after a good high speed run.


Most spark plug color charts were written back when leaded fuel was being used. The un-leaded fuel coupled with modern high efficiently combustion chambers just doesn't color the plugs like the old days.. If the plugs are turning brown you are looking at incomplete combustion on that cylinder..

Twisty
 

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Mag, my recent hands on experience with many different Gold Wings has clearly shown avivid difference in spark plug color when the mixture is incorrect. It is always best to look at what you have in front of you rather than trusting generalizations of people on the internet.

Your spark plug colors indicate a variance in air/fuel ratio between cylinders and the biggest contributing factor, normally,to this sort of problem on a Wing is improperly serviced or dirtycarburetors.You might be wise in pulling the carbs off again and going through them carefully even though you say Honda has already gone through them. I seriously doubt that most "average" Honda dealers would take the actual amountof time required to fully go through these intricate carbs because the final total in dollars would shockyou. LastI heard was that it costs about $800. US toremove, rebuild and replace the carbs and then synchronize them. If you paid less than this amount they most likely just adjusted the floats and cleaned out some dirt. If the extremely small idle jets show any sign of blockage and cannot be cleaned with compressed air or chemicalsthey should be replaced because running a wire through them can alter flow characteristics slightly.

To check your ignition system for potential weak spots use a calibrated spark plug. Take an old spark plug and stretch the gap outto about 1/8" and securely attach it to a spark plug wire then ground the metal body of the plug to the engine. Run the engine and observe the spark output, it should be the same at each one of the plugs, if not there is a problem in the resistor, wire or coil or ignition system.

To check for a vacuum leak you can spray oil at each joint or area where a leak could occur to see if the RPMchanges when the oil enters at the leak. Before running the engine, physically inspect each hose and fitting to determine if the rubber has hardened, split or is loose and may be causing the leak.

Let us know how you make out with it.

Vic

P.S. Turning the mixture screw clockwise richens the mixture and conterclockwise leans the mixture.
 

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Thanks, Vic. The carbs have all new parts, including pilot screws, jets, float valves. I have leak tested each float valve. Since the carbs are probably fine, and i had similar issues with the original carb rack, plus a tank full of rust, i would deduce that rust got through and is jamming up passages and/or float valves. This would explain the flooding in carb #1. What's odd is that prior, that plug would just blacken. The plug wires/caps and coils all test for proper resistance. I will check for vacuum leak, and after that can only assume the carbs are getting rust inside from residue of tank cleaning.
 

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Mag, you might have alreadyseen this but here is some real good information on the GL-1000 carbs & the off idle flat spot & other carb problems.. It is Randakks site & has some real good info onyour carbs.

http://www.randakks.com/TechTips.htm#15
 

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Thanks, Twisty. I've been there lots. Off-idle flat spot is specific to 75-77 models. Just checked for vacuum leaks -- none. Also, the bike is idling dead evenly now. I think it comes down to rust jamming up that #1 carb float, or restriction on the float pin. It's still seeping gas at the float screw, which tells me it's flooding slightly. Otherwise the bike runs awesome after it warms up. It seems to take a little while with the choke/revving to get it to idle on startup, maybe 20 seconds.
 

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mag wrote:
Thanks, Vic. The carbs have all new parts, including pilot screws, jets, float valves. I have leak tested each float valve. Since the carbs are probably fine, and i had similar issues with the original carb rack, plus a tank full of rust, i would deduce that rust got through and is jamming up passages and/or float valves. This would explain the flooding in carb #1. What's odd is that prior, that plug would just blacken. The plug wires/caps and coils all test for proper resistance. I will check for vacuum leak, and after that can only assume the carbs are getting rust inside from residue of tank cleaning.
Hi Mag, have you installed a very fine elementfuel filter on this bike? If not, it might help keep the rust out of your carbs. You might even want to temporarily install a sediment bowl with a magnet at the bottomif you can find one so that you can observe any foreign material in the fuel rather having to tear down the carbs to check for dirt. Check the Harley shops, they have some glass shell fuel filters that you could tape a magnet to while you are running the rust out. It's a lot easier to change the fuel filter than it is to R+R the carbs.

Vic
 

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Vic, i'm just using the OEM fuel filter from the dealer. Not sure where i could get a 'fine' filter. The glass one is a good suggestion, with the magnet.
 

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Mag, use a new original type of fuel filter before the fuel pump and use a fine element filter after the fuel pump. Racor or Wix both have filter elements that are fine enough to prevent water from flowing through them so it will keep the rust out also. Ask for the Racor or Wix filter at any quality auto/marine/diesel supply parts store. It's a little pricey but at least you won't have to keep pulling your carbs to clean the rust out.

Vic
 

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Mag, if you install a very fine element filter make sureit is easily assessable & easily replaceable (or quicklyby-passable).. Those fine element filters plug up quickly if any dirt, rust, or water is in the fuel & can cause an unwanted engine quit while on the road.

If you can find the room to install it, those glass separator type sediment bowl type filters are available form most farm supply storesas they are still used in older farm & heavy equipment. At least with a glass bowl you can see what is flowing in the fuel system.

On that carb leaking? If those carbs have Vitron tipped needles in them it only takes a small spec of dirt or rust to imbed in the needle tip & cause a seeping needle. I do a lot of old tractor & hit & miss engine restoration & have found that using non Vitron tipped (full steel)) needles handles the small amount of rust & dirt better as it won't allow the dirt to imbed in the needle tip..

Twisty
 

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Mag, most fine element filters are used for high volume flow life and extended mileage applications and can be used reliably. Many of these fine element filters will outlast OE filters because they do not break down with water infiltration and since they are designed for long life they tend to give a much greater filtration area to allow fuel to flow through. Normally you wouldn't need this caliber of filter on your Wing but if you have tank rust problems this is by far the simplest method of protecting your carbs until you get the rust issue resolved.

Also, if you decide to use steel needle valves in your Wing, be aware that they can wear quickly due to the high RPM vibrations that your Wing will create and they can also cause aeration of the fuel in the float bowl because they hammer open and closed. The Viton type needle valves are best suited for high RPM applicationsbut the steel needles are OK for tractors and such other low speed types of engines.

Vic
 
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