jw18 Posted June 23, 2012 Share #1 Posted June 23, 2012 I don't know what else to do. My 98 Royal Star keeps pissing gas out of the overflow tubes. I cleaned it, put new jets, new needle valves/seats, and it still pissed gas. I finally got so frustrated that I took it to a local mechanic and he said the floats were way off, charged me $280 and I thought that I was good to go. NOPE!!! I live three and a half miles from his shop. I don't own a trailer and my buddy that does was not available so I rigged a 1L jerry can up thinking that would catch enough gas for 3 1/2 miles. NOPE!! I had to dump the can three times, so that is 1L of fresh out of the pump that day gas per mile! The mechanic has had it for a week and he called me yesterday and said that they had the carb bank on the test bench and hit it with a heat gun and the gas was boiling at 104 degrees, making the floats drop, and pissing gas again. He does not have any solutions. I have no idea where to go from here other than just put the bike up for sale. I WILL loose my ass if I sell this bike not running. Any ideas or help would be greatly appreciated!! Link to comment Share on other sites More sharing options...
MikeWa Posted June 23, 2012 Share #2 Posted June 23, 2012 The mechanic has had it for a week and he called me yesterday and said that they had the carb bank on the test bench and hit it with a heat gun and the gas was boiling at 104 degrees, making the floats drop, and pissing gas again. He does not have any solutions. Get a new mechanic. Gasoline in your carbs does not behave any differently than in any one elses. Mike Link to comment Share on other sites More sharing options...
Marcarl Posted June 23, 2012 Share #3 Posted June 23, 2012 The mechanic has had it for a week and he called me yesterday and said that they had the carb bank on the test bench and hit it with a heat gun and the gas was boiling at 104 degrees, making the floats drop, and pissing gas again. He does not have any solutions. Get a new mechanic. Gasoline in your carbs does not behave any differently than in any one elses. Mike YEP!!!!! Link to comment Share on other sites More sharing options...
jw18 Posted June 23, 2012 Author Share #4 Posted June 23, 2012 Okay, so mechanic is a no go. What can be my problem then? I can't believe the carb could get any cleaner and it has new needle valves and seats. The floats are in good shape and have been adjusted. I live in Birmingham AL. Is there a trusted mechanic anywhere close to me? Link to comment Share on other sites More sharing options...
Snaggletooth Posted June 23, 2012 Share #5 Posted June 23, 2012 I'm not familiar with the '98 carbs but the first thing I would question would be the needles and seats themselves. And I'm going to ask, did the same mechanic install them? If the wrong needles were installed the problem is more than likely there. I've pulled carbs apart with needles that were too short and did not seat at all. But with what you have told so far, the current mechanic needs to be kept away from the bike...... or any bike for that matter. Sounds clueless. Mike Link to comment Share on other sites More sharing options...
jw18 Posted June 23, 2012 Author Share #6 Posted June 23, 2012 I'm not familiar with the '98 carbs but the first thing I would question would be the needles and seats themselves. And I'm going to ask, did the same mechanic install them? If the wrong needles were installed the problem is more than likely there. I've pulled carbs apart with needles that were too short and did not seat at all. But with what you have told so far, the current mechanic needs to be kept away from the bike...... or any bike for that matter. Sounds clueless. Mike They are brand new factory Yamaha seats with screens that came with matching needle valves. I purchased them from the local dealership and installed them myself. They were in factory sealed bags and I checked them against the old ones before install and they were identical. I did the install myself on all of the new parts after a thorough cleaning. The only thing not replaced at this point are the needle jets and the rubber piece that they seat in. Link to comment Share on other sites More sharing options...
Snaggletooth Posted June 23, 2012 Share #7 Posted June 23, 2012 Ok, been looking at the diagrams for your carbs. Compared to the 1st gen carbs the seat replacement is pretty straight forward. Wish the 1st gens were that easy. If this is effecting all four carbs at the same time I keep going back to the fuel level setting through the float adjustment on all four carbs. In my mind that is the only thing that would cause the massive overflow on all four at the same time. Sorry, I got nothing else I can think of right now. Hope somebody can throw some ideas your way. I know where you are at. I had crazy overflow issues with my '84 when I got it. Took me most the first summer and replaced the needles, seats and floats with new and I lost count of how many times the carbs came off to adjust the fuel levels to get them dialed in. I hope you get an answer to the problem soon. Mike Link to comment Share on other sites More sharing options...
Yammer Dan Posted June 23, 2012 Share #8 Posted June 23, 2012 What did you clean them with? Some cleaners are too harsh for these things and can damage the rubber parts. Link to comment Share on other sites More sharing options...
Kirby Posted June 23, 2012 Share #9 Posted June 23, 2012 OK, first off, do not take the bike or any other bike back to said shyster! He doesn't have a clue. If what you said about putting in new jets and seats is true then the only possible answer to this problem is you have the floats set way too high which results in constant overflowing as a result of the fuel pump trying to fill the bowls. In essence you are pumping gas out onto the ground! Look in the tech section on how to adjust the float level. I'm not familiar with your particular bike but this is common to most all bikes with carburetors that have bowls. Remember, if it is overflowing and the bike has a fuel pump or not, the gas has no way to stop flowing on it's own. That is purpose of the floats and float needle valve. Link to comment Share on other sites More sharing options...
Carbon_One Posted June 23, 2012 Share #10 Posted June 23, 2012 Larry Link to comment Share on other sites More sharing options...
Thom Posted June 23, 2012 Share #11 Posted June 23, 2012 what fuel pump do you have ? check your fuel presser , it should be about 4 lbs , if somebody has changed fuel pumps , you could have the wrong pump . Link to comment Share on other sites More sharing options...
Squidley Posted June 23, 2012 Share #12 Posted June 23, 2012 what fuel pump do you have ? check your fuel presser , it should be about 4 lbs , if somebody has changed fuel pumps , you could have the wrong pump . I agree with Thom on the fuel pressure matter. If you have more pressure pushing against the float needles (they are rated for a specific psi) then they will open and you will bypass them. Kirby has very valid points also, your '98 carbs should be similar to the 2nd gen carbs, only smaller. The floats have a measurement that they are set at, and that might not be right. Unfortunately if your not comfortable taking them off yourself, finding a reputable mechanic is your only recourse. I wish I was closer to you as we could go through them in a day. Link to comment Share on other sites More sharing options...
jw18 Posted June 24, 2012 Author Share #13 Posted June 24, 2012 Is there anyone that I could just send the carbs to? I want someone recommended from you guys that know what the hell he is doing. I have wasted all of spring on this issue and well over $600 in parts and labor that I will never see again. I want to get this bike fixed and put a big for sale sign on it. It seems most here have had great dependability with your bikes. I have not been so lucky and this has left a very very bad taste in my mouth. I have never had so many issues with a product that I have ever owned! This thing is worse that a damn boat. The first $3000 and this is off to its new owner and I will never own anything with carbs again. EVER! Link to comment Share on other sites More sharing options...
MikeWa Posted June 24, 2012 Share #14 Posted June 24, 2012 Is there anyone that I could just send the carbs to? I want someone recommended from you guys that know what the hell he is doing. I have wasted all of spring on this issue and well over $600 in parts and labor that I will never see again. I want to get this bike fixed and put a big for sale sign on it. It seems most here have had great dependability with your bikes. I have not been so lucky and this has left a very very bad taste in my mouth. I have never had so many issues with a product that I have ever owned! This thing is worse that a damn boat. The first $3000 and this is off to its new owner and I will never own anything with carbs again. EVER! Ok. Calm down. Take a deep breath. Carbs can be a little bit complicated but not to the extent you are having problems. They have provided reliable fuel metering for over 100 years. The problem is finding someone who understands and knows how to work on them. Experienced motorcycle techs who know what they are doing are hard to find. The service writers act like their techs know everything but they don't. Part of it is a pay issue. Motorcycle mechanics are not that well paid. So by the time someone gets really good they move on. Sometimes they start their own shops. Yes you replaced the parts with quality stuff. My guess is that some little gasket or something was misplaced or installed wrong. A mechanic who is very familiar with your carburetors will see it chuckle and fix it. A tech who isn't familiar with your carbs will probably never see it. And in fact may repeat the mistake because that is the way he took them apart. So your problem is how to find a good carb tech. 1) Do you have a technical college or trade school in your area that teaches motorcycle mechanics? If so drop by and talk to the instructor. He may be able to point you toward a shop that regularly does this kind of work. Or better yet he may want to look at it himself. 2) Scan the phone book for non dealer shops that work on older bikes. Drop in and talk to a few. You should be able to discover who knows about carburetors and who doesn't. ASK something like " do you repair a lot of carburetors?" Then calmly explain your problem and the steps you have taken to this point. Calm calm calm. Best of Luck Mike Link to comment Share on other sites More sharing options...
pmelah Posted June 24, 2012 Share #15 Posted June 24, 2012 jw18 dont give up hope yet i have been working on my bike since aug. of last year and this is my aniversary gift from my wife to me in oct. the mechanice that worked on it made it worse as i have the same problem you do and now i have no money to fix it just dont give up on it yet you can check with tazmocycle he is about 40 mi. from you he has offerd his help to me only i have had to decline his help as i dont have moneyto pay him just look at it this way you bought a problem that can be fixed and will give you plenty of enjoyment in the future i was given a gift problem that i paid for and have to pay to get it fixed what a gift Link to comment Share on other sites More sharing options...
Guest tx2sturgis Posted June 24, 2012 Share #16 Posted June 24, 2012 I'm still scratching my head over the heatgun thing. I have never heard of this. Maybe he was thinking about vaporlock? I dont really know, but I dont believe he got the gasoline to boil at 104 degrees. It doesnt normally boil until its way over 300f. I wonder if they drug test those guys? (doubt it) Link to comment Share on other sites More sharing options...
Kirby Posted June 24, 2012 Share #17 Posted June 24, 2012 I'm with you Brian. I see no earthly reason to try to make the fuel boil. Maybe this something new they teach in some of the hi-tech schools? Link to comment Share on other sites More sharing options...
jw18 Posted June 25, 2012 Author Share #18 Posted June 25, 2012 I don't have any idea why the mechanic did what he did with the heat gun. He is the best BMW mechanic in our area and he works on various different bikes and has been in business for many years. Question for you guys though, what if I adjusted the float bowels lower that factory? Would that possibly help? To address other questions: - Factory fuel pump - Recently replaced fuel filter after the problem started - Bike just turned 30k miles. Link to comment Share on other sites More sharing options...
Squidley Posted June 25, 2012 Share #19 Posted June 25, 2012 Just some info about Gasoline Boiling Point "The boiling point of gasoline varies. At atmospheric pressure, it's between 100 and 400 oF. A primary cause of this variance is the various additives in the gasoline from different refiners designed to meet different octane requirements." If you haven't I would drain the tank and try some fresh gas in it. I personally have never heard of gas boiling in a tank or a carburetor. Thats not to say it doesn't happen, but it seems very unlikely to me that this would cause all your troubles. I'd still wager that it's in either the floats, needles or the seats. That is what controls how much gas gets into the bowls..... Link to comment Share on other sites More sharing options...
jw18 Posted June 25, 2012 Author Share #20 Posted June 25, 2012 Just some info about Gasoline Boiling Point "The boiling point of gasoline varies. At atmospheric pressure, it's between 100 and 400 oF. A primary cause of this variance is the various additives in the gasoline from different refiners designed to meet different octane requirements." If you haven't I would drain the tank and try some fresh gas in it. I personally have never heard of gas boiling in a tank or a carburetor. Thats not to say it doesn't happen, but it seems very unlikely to me that this would cause all your troubles. I'd still wager that it's in either the floats, needles or the seats. That is what controls how much gas gets into the bowls..... I have had gas boil in the summer in my gas tank in a previous bike, so I am familiar with that. It just doesn't make since in a carb because of the air mix that should bring down the temp. I have no clue at this point, I threw my hands up after about the 20th time I took the carbs off and on again with the same results. Link to comment Share on other sites More sharing options...
Flyinfool Posted June 25, 2012 Share #21 Posted June 25, 2012 When you took off the old filter, did you open the fuel filter to check for crud? If a filter has a lot of crud then some may have gotten thru to the carb. If the filter was real bad you may have a lot of crud in your tank. I agree with what others ave said, Fuel flowing out the overflow can ONLY be float, Float needle, or float needle seat. There is a slim outside chance of a possibility of a cracked carb causing this as well, but that is very unlikely. All of the rest of the stuff in the carb can not make fuel come out the overflow. I have seen gas boiling in a float bowl on a car once, but it was just driven 90 miles on the freeway, with NO coolant and the heads were glowing red hot..... Link to comment Share on other sites More sharing options...
jw18 Posted June 25, 2012 Author Share #22 Posted June 25, 2012 When you took off the old filter, did you open the fuel filter to check for crud? If a filter has a lot of crud then some may have gotten thru to the carb. If the filter was real bad you may have a lot of crud in your tank. I agree with what others ave said, Fuel flowing out the overflow can ONLY be float, Float needle, or float needle seat. There is a slim outside chance of a possibility of a cracked carb causing this as well, but that is very unlikely. All of the rest of the stuff in the carb can not make fuel come out the overflow. I have seen gas boiling in a float bowl on a car once, but it was just driven 90 miles on the freeway, with NO coolant and the heads were glowing red hot..... I did not split the filter, but the gas coming out was clear and there was only a slight discoloration to the clear filter body. Link to comment Share on other sites More sharing options...
dacheedah Posted June 25, 2012 Share #23 Posted June 25, 2012 I'm gonna say that gas will not "boil" at 100 degrees, I have seen it written that it will boil between 100-400 degres F. It is the point where it begins to turns to vapor maybe is about 100+, but it gets over 100 here sometimes and I have never seen gas boil, When I was in 29 Psalms it was well over 100 and the gas did not boil, everyone has had gas on their 98.6 degree hands and I am gonna guess it didn't boil... When he said he hit it with a heat gun I am guessing he hit it with a non contact temperature reader ( it measures heat ) at least that's what I'm hoping he did. I am going to agree that as complex as carbs are they are also a very simple system that requires them to be clean to work. I would first check the pressure of the gas coming from the pump and measure that. The pressure is just a few pounds, as a test try bypassing the pump and run on gravity from the petcock , see if it still leaks. If it stops leaking it's a pump issue ( won't run great this way but it will run) . If it still leaks it's the floats, they are the valve the turns the gas off when full. Link to comment Share on other sites More sharing options...
Kirby Posted June 25, 2012 Share #24 Posted June 25, 2012 Ok , one other thing to look for. If the floats are hollow like the used to make them years ago, the floats themselves may be filling up with gas and falling open if the floats have a pin hole in them. This would have the same effect as float levels set way too high. Also this model may be like the 2gens that come from the factory with the float levels set too high. The manual is wrong on this. Goose has a write up in the Tech section on a better way to set the float levels without getting them too high. Link to comment Share on other sites More sharing options...
Kirby Posted June 26, 2012 Share #25 Posted June 26, 2012 Bump!! Link to comment Share on other sites More sharing options...
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