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But mine are the same way, somewhat white. If it does not ping or knock leave it like it is or add 1 washer to slightly richen it up.

If your getting any surging at steady cruise it is lean. If not I leave it alone. I still get 42-48 mpg depending on speed, headwinds, ambient temp's, city driving and 2 up. Water cooled engines are not as sensitive to lean/rich as 2 strokes or air cooled engines are.

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That looks " Lean" to maby " too Lean "

 

Deffinatly , NOT Rich ---

 

Do you still have the old plugs you pulled before doing the needle mod ? compare them if you happen to still have them

Edited by GeorgeS
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Did the 5bikes modification to my 2005 RSTD during my spring tune up. After cleaning and regapping the plugs (original) I replaced the carb plastic washer with a #4 stainless steal washer I found at Lowes. 1 tank of gas later, 171.3 miles without hitting the researve tank, I achieved 45.3mpg up from 38mpg. Happy about that! I just pulled the plug and would like some interpretation!

 

Thanks all and especially 5bikes!!

 

How did you ride while emptying the Tank ? Fast, slow, Highway, Back Roads, WOT, normal or maybe a bit hesitatting ??

 

These Plugs sure look too lean to me, but partly it's how you did ride to get this Plug Colors.

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Thanks everyone for reply's and advice. Being a Texas Aggie I believe I will follow 5bikes' advice, leaving the bike as is, since my bike did not ping and it did not knock, and I did not feel any surges during cruise. I will pull a plug from time to time and monitor the color and eventually I probrably will add another washer. Thanks again, 5bikes

 

OK, Ill try to answer all other questions:

 

GeorgeS I reused the original plugs after cleaning and regapping them since they looked fine. I wish I had taken a picture of the plugs before cleaning them but I'm just not that smart! (See Texas Aggie above!) The plugs did look normal before I cleaned them.

 

Squeeze: I don't know what WOT is. I rode the bike as if I was making a long trip, which is my plan in the near future. I rode normal, through the town and out onto the local highways with speeds from 40 to 75 mph. Cruising speed was usually 60 to 65. I emptied the tank over two trips the first for about 100 miles the second for 71 miles. I have never been a speed demon so I did not do any heavy acceleration.

 

Thanks GeorgeS and Squeeze!

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EPA Regulations ...

 

I'm not into what the EPA are trying to accomplish so I may very well be incorrect in my assessment but my question is: Does having the engine run richer, improve the air quality? That just sounds backwards to me.

 

Dick

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....

 

Squeeze: I don't know what WOT is. I rode the bike as if I was making a long trip, which is my plan in the near future. I rode normal, through the town and out onto the local highways with speeds from 40 to 75 mph. Cruising speed was usually 60 to 65. I emptied the tank over two trips the first for about 100 miles the second for 71 miles. I have never been a speed demon so I did not do any heavy acceleration.

 

Thanks GeorgeS and Squeeze!

 

WOT would be WIDE OPEN THROTTLE :D

 

Based on your Description, the Motor is running too lean in my Opnion.

 

I'm not into what the EPA are trying to accomplish so I may very well be incorrect in my assessment but my question is: Does having the engine run richer, improve the air quality? That just sounds backwards to me.

 

Dick

 

"Improving Air Quality" is relative. There are more Gases than just Carbone Monoxide(CO) in Exhaust Gases, running rich produces more CO, but may reduce other Gases like Nitrogen Oxides. There are also Carbon Hydride, Sulphur Dioxide. Runing lean does not only vary the Fuel Consumption, but also produce more "bad" Exhaust Gases. Carbone Monoxide is "not as bad" as the other Gases. So, the Answer might be "Yes", because an overweight of CO makes the Exhaust Gases not as bad as running CO in a underweighted Condition. Of Course, all those Gases are a bad Thing, so it's Kind of academic, but that why those Catalitic Converters and O2 Sensors are invented for. We're talking about the Motor here, if we would be talking Environment, we should shut down all our Toys first.

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I'm not into what the EPA are trying to accomplish so I may very well be incorrect in my assessment but my question is: Does having the engine run richer, improve the air quality? That just sounds backwards to me.

 

Dick

 

It can, yes. Leaner does not necessarily mean better. There is an A/F ratio at which emissions are the lowest possible. Get richer than that and emissions will go up. Get leaner than that, and emissions will also go up. If the A/F ratio is too lean to begin with, then yes, making the mixture richer will lower emissions.

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It also depends on RPM / engine load. For years MC engines usually have run a little better with the pilot screws richened up a bit. But that's low RPM, low load, low throttle conditions which supposedly comprise a large amount of the factory EPA test. Certainly the test we used to have here in Pima County was idle-only (pilot screws). Get into the needle or main jet range and things may be totally different.

 

Jeremy

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  • 2 weeks later...

I'm new to this site so I've been cruising through some older threads that catch my attention.

I will pull a plug from time to time and monitor the color and eventually I probrably will add another washer.
Pulling a plug after a normal ride won't tell you very much about how the engine is running other than at idle. If you really want to get an accurate plug reading you need to do a chop test at idle speed (OK that's easy), midrange (3000 or so) and WOT (5000 +). Essentially testing each fuel needle/jet range. A chop test is accomplished by running at the desired RPM for a few minutes ( 10 or 15) then pull the clutch and flip the kill switch coasting to a stop. Let the engine cool down a bit before pulling the plugs. Having 4 sets of plugs here is a good thing. Label teach set and take them home to compare to a plug chart that can be found on the Internet.

 

There are quite a few charts littered about but here is one that I happened to have bookmarked:

http://www.dansmc.com/Spark_Plugs/Spark_Plugs_catalog.html

 

Any time you re-jet or shim the plugs should be read to determine proper flow rates in the fuel systems. This may not be very scientific but it's cheaper than dyno testing.

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that is a good link. Makes me feel better looking at my plugs. Also notice the center electrode..starting to get white deposits in the "best" catagory. I don't know how white you can go...? My experience...you want some color on there...as long as it's not dark. Also the new unleaded fuels makes it very difficult to read the plugs. Takes many more miles to really see anything unless you are running WAY rich.

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I have heard, although not yet sorted it out for myself yet, with the newish blended gasoline many now have, reading the plug ceramic insulator is no longer accurate due to it being mostly white indicating a lean condition when in fact it is not lean. Apparently it is often necessary now to read the rim of the plug body depending on the gas mix that is being used.

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Carbon Dixoide, The atmosphere is 78% nitrogen, 21% oxygen, thats 99%. If you use a football for example,100 yards, nitrogen and oxygen take up 99 yards or 297 feet, the rest is inert gases & co2. The last inch and half is co2. In the last 50 years the co2 level has increased 3/8" of an inch. Most Co2 comes from the atmosphere, comes from the evapotation of the Oceans, most of the rest comes from volcanoes. The one that erupted in Chile last year put out more CO2 than all the cars in the history of all the cars in the U.S. So I am not going to worry about something I cannot do anything about.

 

tew47

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I have heard, although not yet sorted it out for myself yet, with the newish blended gasoline many now have, reading the plug ceramic insulator is no longer accurate due to it being mostly white indicating a lean condition when in fact it is not lean. Apparently it is often necessary now to read the rim of the plug body depending on the gas mix that is being used.

 

I've been hearing most of that for 15 years, that plug reading really doesn't work anymore 'cause the fuels are cleaner. Dynojet for years has not recommended plug reading but rather riding behavior - pinging, surging, etc, and does it get better or worse if you tape off a bunch of the air filter surface? Long time engine builder David Vizard says plug reading has always been really difficult to do accurately. You're actually supposed to look down in the annular gap where the ceramic meets the metal. Or so I've read. As for the rim of plug body, it's pretty much always dark or black, so I don't see that as a viable option.

 

Jeremy

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I've mentioned before that I lowered my needles .050" for a gain of 8% or so. Here's some new info. I had always noticed that my 87 VR averaged almost 2 mpg less in the summer than the winter. Keep in mind that I am in Tucson, so winter riding is 30-70 deg F and Summer riding is 70-110 deg F. It used to be something like 35 summer, 37 winter. I can now report that with the needle mod I still have the same disparity between seasons, except that now it's 38 summer and 40 winter. On tanks when I've purposely taken it REALLY easy I've topped out at 40 summer and 43 winter.

 

Why this disparity, I always wondered? I recently came up with what I think is a likely cause - wind resistance. In the winter I'm tucked behind the fairing, rarely using my highway bars and the Baker Air Wings are closed. In the summer I want all the air I can get, feet stickin' way out there a lot of the time, air wings wide open scooping the breeze.

 

Jeremy

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Also, I believe I have heard / read that Winter Gas is a different mixture than Summer Gas.

 

I know this is true with diesel fuel but I think gas is the same year around.

 

I would guess getting better gass milage in cooler weather would have something to do with the air being more dense.

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No, gas does change formulation seasonally in two ways I am aware of. Some places, here included, offer oxygenated fuel for supposed emissions benefits, but it vapor locks too easily to do it in the summer here. And even barring that, they modify the volitility of the fuel based on the average temperature for the same reason.

 

Denser air would make mileage better if carbs are on the rich side. I think. Maybe. At least that's what makes sense to me. So I wondered if the needle leaning thing would bring summer mileage up more since the lower-density air would work better with the leaner mixture. Well, that theory failed to materialize.

 

Interestingly, I've read from at least two others here that their summer mileage is BETTER than winter mileage. I've never noticed this kind of seasonal difference before on my cars or bikes. So the wind resistance thing, which is somewhat unique to this bike with its full-fairing, makes sense to me. I could be all wrong though!

 

Jeremy

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I have an '85 that does not have the adjustable needles. The spacer was.098" and I replaced it with two #6 washers that measured .052" overall. The best I ever got before was 34 mpg, normally around 30. I have her on a trip from La Crosse WI to Ashtabula OH and I have averaged 42 mpg over the 1100 miles so far (most of that at 70 mph). No surge, runs same temp as before and starts the same as before. THANK YOU!!

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My spacers also measured right at about .100". However, there is also a little protrusion that sticks off the bottom of them which holds them up another .020, making the actual effective thickness .120". I wonder if yours are the same? If so, that would mean you dropped them from .120 to .052, a change of .068".

 

I dropped mine from .120 to about .070. I did it in a couple steps; I didn't notice much difference at .090, but from .090 to .070 was 3 mpg average increase. I wonder if another .015 or .020 would do mine like it did yours??

 

Jeremy

Edited by Gearhead
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