juggler Posted July 16, 2009 Share #1 Posted July 16, 2009 (edited) This is something I've been dealing with ever since I took my 99 RSV into the dealer a few years ago to have them fix my carbs because gas was pouring out of my overflow tube on the left side. They fixed that problem, but ever since my gas mileage has been on the low 30's. Black Owl and I have carb tuned it and last year at Pork in the Pines I used the color tune to check the fuel air mixtures. The fuel air mix appeared to be ok with a nice blue flame in each cylinder. But I've had all winter and spring to get up the courage and start adjusting the mixture on each carb. So I started by turning each mixture screw in 1/4 turn then running a few tanks of gas to see if things improved. After the second time there was a little mpg increase to about 36mpg (up from 34) and the nasty gas smell was gone. So I tried a third time. Mileage went down a bit and the gas smell came back. By this time I had turned each screw in 3/4's of a turn total. I had read on these forums somewhere that you should start with the mixture screws at 2 1/2 turns out if say you were rebuilding your carbs and needed to start at a base line. So last night I carefully turned each screw all the way in while counting the turns and reset each one to 2.5 turns out. Here are the counts for each carb as I turned the mixture screws all the way in. carb #1 3+ turns in carb #2 3+ turns in carb #3 2 3/4 turns in carb #4 2 1/2 turns in This after I had already turned each in by 3/4 turns over the past month. Questions: 1. Were those mixture screws out way too far? 2. Did I do the right thing by adjusting them all to 2.5 turns out? It runs pretty good today. I have not ridden far enough to see if MPG changed. 3. Is there a better tool besides the colour tune to determine air fuel mixture? It is pretty subjective as to the correct color shade of the blue flame. If not, I may beg to borrow a colour tune again. 4. I know I should re-sync the carbs after all this. Black Owl, you got the time to help? 5. is there anything else I should check? ============================== Update I should have mentioned the plugs are good. I replaced them last fall. Only about 4k on them. The headers heat up evenly, I already thought of that. I should buy stock in seafoam as I use so much of it. (1 can about ever other month) I don't have a tach, but I did buy a meter that is supposed to measure RPM with a clamp over the #1 plug wire. 1000RPM?? Really that high? When I pulled the old plugs last fall at Pork in the Pines, they looked good. Nice tan color to them. No clue on the AIS. I bought this bike used a few years back. No popping on deceleration anymore. There used to be popping before I took it in for repair a few years ago. HOWEVER, I had amazing Howitzer like backfire almost on command during deceleration until I started adjusting the mixture screws. Update (again): I have K&N air filters and I take care of them routinely. Edited July 17, 2009 by juggler Link to comment Share on other sites More sharing options...
Black Owl Posted July 16, 2009 Share #2 Posted July 16, 2009 I think I can do that. Will get me away from cutting up all the trees I had taken down last week. Dang it's tuff to be an Ol fart.... Link to comment Share on other sites More sharing options...
Leland Posted July 16, 2009 Share #3 Posted July 16, 2009 How many miles do you have on the spark plugs? I changed mine at 11,000 miles just because the manual says to change them at 8,000 and they are cheap. I couldn't believe it, but my mileage jumped a good 10%. Just put in the standard NGK (came with Denso) Link to comment Share on other sites More sharing options...
V7Goose Posted July 16, 2009 Share #4 Posted July 16, 2009 Well, there is lots of stuff to talk about here, so I'll just start a brain dump in no particular order - hope it makes some sense. The mixture screws are primarily just for idle and partial throttle mixture, so adjusting them probably won't make a big difference in MPG. IMHO, the Colortune is just next to worthless. You can turn the screw seemingly forever between the color shifts from too lean to too rich, so leaving it somewhere in between is still a crap shoot. I have an exhaust gas analyzer, and I know for a fact that 1/4 turn makes a big difference in the CO%, so that really emphasizes how worthless the Colortune is. I have found that tuning by ear (a tach is even better) can get this engine very close to what I do with the exhaust gas analyzer. But you need to be sure everything else is good before you do that. Turn a screw out slowly to find the fastest idle, then back in by 1/4 turn. Do that for each carb, adjusting the idle speed screw as necessary to keep your engine around 1,000 RPM. When I have checked factory settings on the untouched mixture screws, they have been around 2 1/4 out (going from memory here - Tom can check his notes and let us know for sure). Best setting with the analyzer is usually somewhat over 3. If you can't come up with anything useful by the RPM method above, just set them all to 3 out and forget it until you can get it done with an exhaust gas analyzer. BEFORE you do anything else, properly set the float levels. This can have a very significant affect on MPG. Make certain your plugs are good. Messing with the floats or the mixture screws will have no effect on the carb sync, but it never hurts to check it, so do that. I think you are fooling yourself trying to measure gas mileage in just one or two tanks. I have talked about this in detail in other threads, but there are just too many variables in both the EXACT amount of gas you put in a small motorcycle tank, and the riding conditions. I already mentioned good plugs - ditto for the air filters. Can't go wrong keeping Seafoam or 44K in your gas throughout this process - won't hurt anything, and it will keep cleaning if there is anything to clean. Do the fingertip test on the header pipes right next to the clamps on a cold engine - be certain they are all heating up at the same speed. Don't know if your AIS is connected or not, but if it is, the lack of popping will show that your combustion is good. If you have any popping at all, it is an absolute indicator you still have something else to find and fix. Once you have all that done and have run a couple of tanks through to be certain it all seems to run good, consider reading the plugs at normal cruising speed, around 3,000 RPM (an indicated 70 in 5th if you don't have a tach). To do that, you need to get it to and hold 3,000 RPM in normal cruising gear for a few miles, then simultaneously kill the engine and pull in the clutch so the engine stops turning over instantly while the throttle is held in that position. Coast to the side of the road and pull the rear plugs (easy to get to, and you want to see that at least two of them look the same. You probably want to keep those plugs out for reference, so have a couple of old (or new) plugs with you to replace them. The plugs you take out should be very clean and tan to very light chocolate color. Guess that's about all for now - Goose Link to comment Share on other sites More sharing options...
Tom Posted July 16, 2009 Share #5 Posted July 16, 2009 [quote - Tom can check his notes and let us know for sure). Best setting with the analyzer is usually somewhat over 3. QUOTE] Mine were as follows Left Rear=2.75 turns , Left Front= 2.25 turns , Rt Rear=2.50 turns , Rt Front=2.50 turns. Also Check next thread I write simply as V7Goose! Link to comment Share on other sites More sharing options...
juggler Posted July 17, 2009 Author Share #6 Posted July 17, 2009 How many miles do you have on the spark plugs? I changed mine at 11,000 miles just because the manual says to change them at 8,000 and they are cheap. I couldn't believe it, but my mileage jumped a good 10%. Just put in the standard NGK (came with Denso) I forgot to mention that I changed them out at Pork in the Pines last fall also, so these plugs have about 4k miles on them. Link to comment Share on other sites More sharing options...
juggler Posted July 17, 2009 Author Share #7 Posted July 17, 2009 Well, there is lots of stuff to talk about here, so I'll just start a brain dump in no particular order - hope it makes some sense. The mixture screws are primarily just for idle and partial throttle mixture, so adjusting them probably won't make a big difference in MPG. IMHO, the Colortune is just next to worthless. You can turn the screw seemingly forever between the color shifts from too lean to too rich, so leaving it somewhere in between is still a crap shoot. I have an exhaust gas analyzer, and I know for a fact that 1/4 turn makes a big difference in the CO%, so that really emphasizes how worthless the Colortune is. I have found that tuning by ear (a tach is even better) can get this engine very close to what I do with the exhaust gas analyzer. But you need to be sure everything else is good before you do that. Turn a screw out slowly to find the fastest idle, then back in by 1/4 turn. Do that for each carb, adjusting the idle speed screw as necessary to keep your engine around 1,000 RPM. When I have checked factory settings on the untouched mixture screws, they have been around 2 1/4 out (going from memory here - Tom can check his notes and let us know for sure). Best setting with the analyzer is usually somewhat over 3. If you can't come up with anything useful by the RPM method above, just set them all to 3 out and forget it until you can get it done with an exhaust gas analyzer. BEFORE you do anything else, properly set the float levels. This can have a very significant affect on MPG. Make certain your plugs are good. Messing with the floats or the mixture screws will have no effect on the carb sync, but it never hurts to check it, so do that. I think you are fooling yourself trying to measure gas mileage in just one or two tanks. I have talked about this in detail in other threads, but there are just too many variables in both the EXACT amount of gas you put in a small motorcycle tank, and the riding conditions. I already mentioned good plugs - ditto for the air filters. Can't go wrong keeping Seafoam or 44K in your gas throughout this process - won't hurt anything, and it will keep cleaning if there is anything to clean. Do the fingertip test on the header pipes right next to the clamps on a cold engine - be certain they are all heating up at the same speed. Don't know if your AIS is connected or not, but if it is, the lack of popping will show that your combustion is good. If you have any popping at all, it is an absolute indicator you still have something else to find and fix. Once you have all that done and have run a couple of tanks through to be certain it all seems to run good, consider reading the plugs at normal cruising speed, around 3,000 RPM (an indicated 70 in 5th if you don't have a tach). To do that, you need to get it to and hold 3,000 RPM in normal cruising gear for a few miles, then simultaneously kill the engine and pull in the clutch so the engine stops turning over instantly while the throttle is held in that position. Coast to the side of the road and pull the rear plugs (easy to get to, and you want to see that at least two of them look the same. You probably want to keep those plugs out for reference, so have a couple of old (or new) plugs with you to replace them. The plugs you take out should be very clean and tan to very light chocolate color. Guess that's about all for now - Goose I should have mentioned the plugs are good. I replaced them last fall. The headers heat up evenly, I already thought of that. I should buy stock in seafoam as I use so much of it. I don't have a tach, but I did buy a meter that is supposed to measure RPM with a clamp over the #1 plug wire. 1000RPM?? Really that high? When I pulled the old plugs last fall at Pork in the Pines, they looked good. Nice tan color to them. No clue on the AIS. I bought this bike used a few years back. No popping on deceleration anymore. There used to be popping before I took it in for repair a few years ago. HOWEVER, I had amazing Howitzer like backfire almost on command during deceleration until I started adjusting the mixture screws. I have no clue how to adjust the float levels. That sounds like I have to pull the carbs off the bike. I grew up in my Dad's gas station garage working on cars. Carbs and transmissions are my demons. I'd rather rebuild a 318 than pull the carbs off this bike. Link to comment Share on other sites More sharing options...
CrazyHorse Posted July 17, 2009 Share #8 Posted July 17, 2009 Nice write up V7. Link to comment Share on other sites More sharing options...
V7Goose Posted July 17, 2009 Share #9 Posted July 17, 2009 I should have mentioned the plugs are good. I replaced them last fall. The headers heat up evenly, I already thought of that. I should buy stock in seafoam as I use so much of it. I don't have a tach, but I did buy a meter that is supposed to measure RPM with a clamp over the #1 plug wire. 1000RPM?? Really that high? When I pulled the old plugs last fall at Pork in the Pines, they looked good. Nice tan color to them. No clue on the AIS. I bought this bike used a few years back. No popping on deceleration anymore. There used to be popping before I took it in for repair a few years ago. HOWEVER, I had amazing Howitzer like backfire almost on command during deceleration until I started adjusting the mixture screws. I have no clue how to adjust the float levels. That sounds like I have to pull the carbs off the bike. I grew up in my Dad's gas station garage working on cars. Carbs and transmissions are my demons. I'd rather rebuild a 318 than pull the carbs off this bike. Sounds like your AIS is still connected, that is a good thing - both for our air and as an indicator of problems with your ignition or fuel mixture. The idle spec on this engine is 1,000 RPM. I'd prefer it a little lower, but the oil pressure at idle is so danged low, I think it is best to keep it at the spec. Do the floats. I have a detailed write-up in the tech library on it - almost impossible to screw anything up. Yes, you do have to pull the carbs - not really hard, but there is a lot of stuff to work through. Goose Link to comment Share on other sites More sharing options...
juggler Posted July 17, 2009 Author Share #10 Posted July 17, 2009 Sounds like your AIS is still connected, that is a good thing - both for our air and as an indicator of problems with your ignition or fuel mixture. The idle spec on this engine is 1,000 RPM. I'd prefer it a little lower, but the oil pressure at idle is so danged low, I think it is best to keep it at the spec. Do the floats. I have a detailed write-up in the tech library on it - almost impossible to screw anything up. Yes, you do have to pull the carbs - not really hard, but there is a lot of stuff to work through. Goose I read your write up and then I read Freebird's post about the hell he went through pulling his carbs. No way in hell am I trying that. I've been learning to work on as many aspects of this bike as I can. I've never been friends with carburetors and never has one survived me taking it apart. Even in small engine shop, those simple little carbs never worked right after I "fixed" them. Link to comment Share on other sites More sharing options...
Condor Posted July 17, 2009 Share #11 Posted July 17, 2009 I should buy stock in seafoam as I use so much of it. Seafoam will reduce the volitivity of the fuel. Using a lot could effect your MPG. It's great for cleaning out carbs etc., and a full can into a full tank will work wonders when a scoot is giving you problems, but you might try running a few tanks of straight regular and see if things don't improve. Once things are cleaned out a couple of ozs per tank is all you'll need. Link to comment Share on other sites More sharing options...
Squeeze Posted July 17, 2009 Share #12 Posted July 17, 2009 Seafoam will reduce the volitivity of the fuel. Using a lot could effect your MPG. It's great for cleaning out carbs etc., and a full can into a full tank will work wonders when a scoot is giving you problems, but you might try running a few tanks of straight regular and see if things don't improve. Once things are cleaned out a couple of ozs per tank is all you'll need. Not to mention a very important Thing .... When a heavy dose of Sea Foam has settled in the Carbs for some Time, ride it like you stole it .... Which means, no 4th Gear, no 5th Gear on a 2Gen. Get on it and let the Rev Limiter do it's Job once in a while, let it pull and suck Fuel through every Fuel Passage and Fuel jet there ist inside. Accelerate in 2nd Gear near Redline and when it's clear behind you, let the Throttle go for some Seconds. Creating such a Vaccuum causes also a good Vacuum inside the Carbs and helps loosen all Crud and Varnish and get them out of the Passages. This helps also keeping the Plugs clean and working. Link to comment Share on other sites More sharing options...
craigatcsi Posted July 17, 2009 Share #13 Posted July 17, 2009 Not to mention a very important Thing .... When a heavy dose of Sea Foam has settled in the Carbs for some Time, ride it like you stole it .... Which means, no 4th Gear, no 5th Gear on a 2Gen. Get on it and let the Rev Limiter do it's Job once in a while, let it pull and suck Fuel through every Fuel Passage and Fuel jet there ist inside. Accelerate in 2nd Gear near Redline and when it's clear behind you, let the Throttle go for some Seconds. Creating such a Vaccuum causes also a good Vacuum inside the Carbs and helps loosen all Crud and Varnish and get them out of the Passages. This helps also keeping the Plugs clean and working. THAT sounds more like abuse!! Link to comment Share on other sites More sharing options...
Squeeze Posted July 17, 2009 Share #14 Posted July 17, 2009 THAT sounds more like abuse!! You never will do any "Abuse" to your Motor going along my Recommendation. You probably even can't imagine how much real "Abuse" those Motors can stand without any Damage. Those Engines are tough and they take real hard beating for a loooooooong Time until they even show any wear. Ever been to a Vmax or Streetfighter Meeting ? Some Folks burn out 20 Tires per Day without harming anything except the Clutch. THAT is beating or abuse, but as long as you don't overrev the Engine, don't let it run boiling hot or get on it when the Motor is cold, you'll never ruin the Engine. Others let their Max Bang a half Day ... You know, rev it up to 8000, Killswitch, Full Throttle, let Throttle go, Killswitch, BANG, Rev it up, Killswitch, full Throttle, let Throttle go, Killswitch, BANG and on and on .... Link to comment Share on other sites More sharing options...
Condor Posted July 17, 2009 Share #15 Posted July 17, 2009 THAT sounds more like abuse!! Believe me when I say the hitting of your rev limiter on a second gen...does not constitute abuse. Everything Squeeze has suggested is right on..... Link to comment Share on other sites More sharing options...
juggler Posted July 17, 2009 Author Share #16 Posted July 17, 2009 (edited) Seafoam will reduce the volitivity of the fuel. Using a lot could effect your MPG. It's great for cleaning out carbs etc., and a full can into a full tank will work wonders when a scoot is giving you problems, but you might try running a few tanks of straight regular and see if things don't improve. Once things are cleaned out a couple of ozs per tank is all you'll need. I run a can once in the spring and about once every other month after that. I run lots of so called straight gas (Ethanol 10% blend crap). Also, this bike never sits more than a day without riding. I've ridden it to work everyday since mid April. It gets ridden most every Saturday and sometimes on Sundays. Edited July 17, 2009 by juggler Link to comment Share on other sites More sharing options...
GeorgeS Posted July 17, 2009 Share #17 Posted July 17, 2009 Believe me when I say the hitting of your rev limiter on a second gen...does not constitute abuse. Everything Squeeze has suggested is right on..... Agreed !! Take it out, and RUN it!! Climb a few Mountains, in 3rd gear ( if you have any handy near your place ) Or just cruz at 60 mph, in 3rd gear for 10 or 20 miles. Its NOT a Harley !! Have you ever DRAINED, the fuel tank !! Have you ever DRAINED, all 4 Carbs ??? Its a good idea to once in awhile. ( Add some HEET, and Drain everything ) and start with all NEW Fuel Has your fuel filter ever ben replaced ??? How long since your AIR FILTERS, have been replaced ?? The Ignition Coils, on 2nd gens have a bad reputation, of going bad progressivly, especialy the rear coils, due to heat, you might consider the possibility of a " sick " Ignition Coil--- How many miles on this bike ?? This could, ( or might ) be a factor. Have you opened, and cleaned, and applied dialectric greese to " ALL Electrical Connectors on this bike ?? " ( Includeing the TCI Plugs ) Have you CLEANED, the Contacts of the " RUN - STOP " Switch, on right handle bar ? AS Squeez, said-- the Idle Mix jets, only effect idle, the correct setting is " about " 2 1/4 turns open " from the full closed position. ( this will have neglidgable effect on fuel milage ) Do you have a " Morgan Carb Tune Tool " ?? if not, get one, and ReSet the adjustment of the throttle Linkage. ( I reset the SYNC, about Twice a year ) IT IS ALWAYS OUT OF ADJUSTMENT, EACH TIME--- If you are getting about 36 to 38 MPG, for average around town, and urban road driveing, thats about normal. If you hit the freeway, and cruz thru a full tank ( no city driveing included ) of fuel, and get 41 to 42 on that trip, thats about normal. ( ie; gas station to gas station, on the freeway ) Thats what I got on a 130 mile leg of a highway Trip Yesterday. 42.3 MPG ( I know, some folks are claiming 46 to 48, by fine tuneing the Needle Jets !! ) I am planning on doing that myself, haven't got to it yet. Link to comment Share on other sites More sharing options...
Black Owl Posted July 17, 2009 Share #18 Posted July 17, 2009 Also, this bike never sits more than a day without riding. I've ridden it to work everyday since mid April. I get ridden most every Saturday and sometimes on Sundays. http://smilies.sofrayt.com/eng/lol6.gif Oh to be young again.... Sorry Wil, http://smilies.sofrayt.com/eng/laughing5.gif I tried real hard but just couldn'c contain (restrain) myself. Can I say the devil made me do it? Link to comment Share on other sites More sharing options...
juggler Posted July 17, 2009 Author Share #19 Posted July 17, 2009 Agreed !! Take it out, and RUN it!! Climb a few Mountains, in 3rd gear ( if you have any handy near your place ) Or just cruz at 60 mph, in 3rd gear for 10 or 20 miles. Its NOT a Harley !! Have you ever DRAINED, the fuel tank !! Have you ever DRAINED, all 4 Carbs ??? Its a good idea to once in awhile. ( Add some HEET, and Drain everything ) and start with all NEW Fuel Has your fuel filter ever ben replaced ??? How long since your AIR FILTERS, have been replaced ?? The Ignition Coils, on 2nd gens have a bad reputation, of going bad progressivly, especialy the rear coils, due to heat, you might consider the possibility of a " sick " Ignition Coil--- How many miles on this bike ?? This could, ( or might ) be a factor. Have you opened, and cleaned, and applied dialectric greese to " ALL Electrical Connectors on this bike ?? " ( Includeing the TCI Plugs ) Have you CLEANED, the Contacts of the " RUN - STOP " Switch, on right handle bar ? AS Squeez, said-- the Idle Mix jets, only effect idle, the correct setting is " about " 2 1/4 turns open " from the full closed position. ( this will have neglidgable effect on fuel milage ) Do you have a " Morgan Carb Tune Tool " ?? if not, get one, and ReSet the adjustment of the throttle Linkage. ( I reset the SYNC, about Twice a year ) IT IS ALWAYS OUT OF ADJUSTMENT, EACH TIME--- If you are getting about 36 to 38 MPG, for average around town, and urban road driveing, thats about normal. If you hit the freeway, and cruz thru a full tank ( no city driveing included ) of fuel, and get 41 to 42 on that trip, thats about normal. ( ie; gas station to gas station, on the freeway ) Thats what I got on a 130 mile leg of a highway Trip Yesterday. 42.3 MPG ( I know, some folks are claiming 46 to 48, by fine tuneing the Needle Jets !! ) I am planning on doing that myself, haven't got to it yet. I run K&N air filters and clean them every spring. With less that 10k of riding per year that is good enough. I wish I was getting that good of mileage. 34-35 mpg on the highway no stops with the cruise on and little to no wind. Same for in town driving. Black Owl has the carb tune and we've done this bike at least once last year with no effect on the mileage. We are planning another time soon. What are mountains, do have those in Minnesota? I've never drained the tank. I think the fuel filter was replaced at the dealer two years ago. So they claimed. I've suspected the coils after reading what Freebird has writing about this similar issue with his bike. The bike has 81k miles on it now. Doesn't Seafoam do the same thing as HEET plus cleaning the fuel system? Link to comment Share on other sites More sharing options...
juggler Posted July 17, 2009 Author Share #20 Posted July 17, 2009 I think I can do that. Will get me away from cutting up all the trees I had taken down last week. Dang it's tuff to be an Ol fart.... How about Sunday afternoon? say around 2 or 3 pm? Link to comment Share on other sites More sharing options...
Squeeze Posted July 17, 2009 Share #21 Posted July 17, 2009 Maybe too much Oil on the K&N Filter ? They don't need much of Oil. A little Shot from 12 Inches away from the Filter is enough. If you overspray, you're actually restricting the Air Flow. Link to comment Share on other sites More sharing options...
craigatcsi Posted July 17, 2009 Share #22 Posted July 17, 2009 I don't mean to steal this thread or argue, but.... The harder you work any machine, the sooner it wears out, right? I always thought that is why we all want the car that was driven only on Sundays, by a little old lady, back and forth to Church. When I sell MY bike, the person getting it will be getting a welll taken care of, not abused bike, or ridden hard - like I would want to buy. I would NEVER knowingly buy a bike that has been ridden as you describe. Now to step off my soapbox... I HAVE taken my bike and run her hard - buried the speedo, just to see what she would do. Believe me, I am not one of those guys that wraps myself in mattress padding, goes way under the speed limit, won't ride in the rain, etc... I LOVE the power she has when I want to pass someone. I just don't ride my tourer like I would a crotch-rocket, (throw away bike). That being said, I'm done. craigr Link to comment Share on other sites More sharing options...
Squeeze Posted July 17, 2009 Share #23 Posted July 17, 2009 Well, maybe you misunderstood my Posting. Just to make it clear: I didn't say you should ride your Bike allways hard and rough all Day ... I said, you should ride it hard when you're using heavy Doses of Sea Foam after the Sea Foam has settled for some Time and made it's Way into those clogged Fuel Passages inside the Carbs. The chemics make the Crud come loose, but you need to break it down and run it out of the System ... Link to comment Share on other sites More sharing options...
Black Owl Posted July 17, 2009 Share #24 Posted July 17, 2009 How about Sunday afternoon? say around 2 or 3 pm? That will work If anything comes up to change that, I'll give you a call. Link to comment Share on other sites More sharing options...
GeorgeS Posted July 18, 2009 Share #25 Posted July 18, 2009 Sorry about the Mts. I grew up in Minn. should have known better --- Link to comment Share on other sites More sharing options...
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