[JordanMix]

what is the recommended fuel flow in ML per minuet out of the petcock? I am having some problems that i have traced back to fuel supply and i think it may be that my carb is not getting enough fuel from the tank. I measured about 6 times and each time i am getting about 200-215 ML per minuet from the petcock with the fuel line running into a measuring vessel. I have removed the petcock, disassembled it and removed any gunk with no change in flow.

I have seen some post on other boards that suggest 250 ML ever 30 seconds, if this is the case i am way off.

I think i have a triumph petcock in the garage, maybe that will fit to see if i have some better flow. Any thoughts or suggesting are much appreciated. just want to make sure i am not chasing this in the wrong direction.

[mrunderhill1975a]

I just checked the Snidal manual and it says:

"Placing the open end of the line in a clear glass jar, turn the tap back on, and observe the rate of fuel flow. It should fill up a 250ml (8 oz) jar in 30 seconds or less. "

Generally speaking, Pete seems to know what he is talking about.

[mrunderhill1975a]

It just occured to me that you may want to check the vent hole in the gas cap, if it is partially or completely clogged, the fuel flow would be restricted.

[JordanMix]

thanks for the replies. I did think about the cap causing the problem so i took the cap completely off and ran a test twice with the same results. looks like a new petcock is necessary. Strange that is just happened out of no where and even after disassembling the unit and cleaning it nothing changes.

[mtrude]

Hello , for what its worth I had a similiar problem and in cleaning the petcock i found it needed the tube for the run position reamed or cleaned as the tanked contained more dirt and debris than I had ever seen. Also the filter in the petcock seems suceptible to damage also. Have fun, mtrude

[t120rbullet]

Are you having fuel starvation problems?
Did you clean BOTH the fuel strainers?
The one inside of the tank and the one underneath the petcock?
CJ

[JordanMix]

yes i have a sudden unset of fuel starvation problems. My bike is running lean and it is having idling problems wants to stall out at low speeds. i adjusted the carb for 2 days with no changes. After measuring the fuel flow i am confident this is the problem.

I have cleaned both screens. I removed the lower unit and cleaned it out, it barely had anything. Once i removed the petcock from the tank i removed the mesh screen on the inside filter and blew out everything. What is confusing to me is that the flow is the same both on the main and reserve. You would think that if one was clogged the other would be open. I am going to try to blow out of fuel line tonight and see if that helps. I also have a Triumph petcock that should fit i will see how that works.

[cyrusb]

But you do have flow, although less than what Dr Snides recomends. I would think it is still more than your bullet can use at any throttle setting. You just need enough to keep your float bowl full. Start looking elsewhere.

[mtrude]

Hello , Would the amount of fuel in the tank effect the flow rate?  have fun, mtrude

[JordanMix]

im not sure if it would or not. I have about 2 gallons in their now and i have run with much less so i doubt that is the cause.

[cyrusb]

So if the screens are clean and fuel is running out of the petcock , the next place to look is downstream at the carb.

[JordanMix]

already did work on the carb. i traced it back to fuel. I am not even getting half of the amount per minuet that is recommended in Pete Snidals manual. i am getting just over 200 ML per minuet, he recommends 250ML in 30 seconds.

[cyrusb]

I'm having a hard time believing that  250ml a minute is not enough to run that engine.  Its a 70 mpg motor, not a 454. All you need is a full float bowl, and it seems to me that rate will do that. Why shouldn't it? If everything is clean, then the rate your seeing is the rate its allways had and ran ok with. no?

[baird4444]

yes i have a sudden unset of fuel starvation problems. My bike is running lean and it is having idling problems wants to stall out at low speeds. i adjusted the carb for 2 days with no changes. After measuring the fuel flow i am confident this is the problem.
I have cleaned both screens. I removed the lower unit and cleaned it out, it barely had anything. Once i removed the petcock from the tank i removed the mesh screen on the inside filter and blew out everything. What is confusing to me is that the flow is the same both on the main and reserve. You would think that if one was clogged the other would be open. I am going to try to blow out of fuel line tonight and see if that helps. I also have a Triumph petcock that should fit i will see how that works.

First off; I think you'll be surprised how simple the reserve side is. The inlet for "ON" is just a littlle taller in the tank than the reserve inlet. When you flip to reserve you are only switching to a lower inlet in the tank. If you werre to leave it on reserve you would just run out of gas at a lower level...    It's a real head slapper when you remove the tap from the tank and see it.
    ok, you've blown out the screens in the tap...   
same problem...
gas cap vent is clear...
Have you pulled the carb and blown out every hole and orifice you can find? Blow them from both directions...   inspect needle; re-set float; and I'm betting that BOB is gonna be your uncle.
                - Mike

[JordanMix]

I completely disassembled the petcock and drilled out the holes a bit more and I’m still only getting about 200 ML a minuet straight from the petcock and also through the carb with the bottom float bowl hexnut cap removed.

I know most people on here have said that 200 ML should be more than enough but there seems to be no agreed upon number. I have read quotes from Peter Snidal that says 250 ML every 30 seconds and then in his manual it says 1 liter a minuet (which seems way to much to me). I kinda just gave up on the flow as it seems adequate for the bullet and I have cleaned everything out so I am assuming it was always flowing at 200 ML.

I have the same jets in that I always did and I have blown each hole out with air and carb cleaner probably 5 times each. I started to play around with the float level last night but I didn’t make any progress.

Can someone answer a few questions on float height for me:

I have seen 15-17 MM listed as a float height as well as 25-28 MM. Which is correct? Also, where do you measure from. I would assume that you are going from the gasket surface to the top center of each float chamber? There are also some variables… do you let the weight of the float rest onto the needle assembly and measure it that way or do you elevate the float assembly so that the tang just touches the float needle and measure it that way?

When making adjustments do you bend the actual float chambers up and down or do you bend the angle of the tang that suppresses the needle assembly?

Here is a big one and may be obvious to some but I don’t know the answer. If you are looking at the carb with it mounted to the bike with the float bowl removed would raising or lowering the floats lean out the mixture?

I don’t know if all of this is common knowledge but it really should be included in the Workshop manual and Peter Snidals manual… it is not in the editions I have.

[Kevin Mahoney]

turn the carb upside down, let the float rest on the needle so that it's weight is on it. I would then measure 25mm from the gasket surface to the top of the float. If it needs adjusting bend the tang being careful not to put the strain of bending on the needle. In other words raise it slightly off the needle when bending. If you set the float at a lesser height the bowl will fill more and it will have a tendency to run rich.
Now.......I am suspecting that your problem may not be fuel related at all. What year is your bike and please describe the symptoms in more detail. I will do my best to get back to you ASAP, but I commute back to PHX from MSP tonight and it may not be until sometime tomorrow

[JordanMix]

thank you for the reply.

I have a 1999 (early, made in May) 500 Bullet.

I have been trying to dial my carb in so i have the ideal setting. I was running a bit to rich at low speed/idle so i thought i would try to 27.5 jet rather than the 30 i had installed. I put this in and it ran awful. The bike would spit, and cough when starting up then when i would try to ride it the bike would hesitate and jerk... i could tell it was running way to lean. I went back to my garage and put the 30 back in thinking i would just deal with the richness problem. I went to go out for a ride and the sale problem persisted that i had with the 27.5. I could get the bike to idle somewhat ok (not as good as before) but as soon as i would put it in gear and hit the throttle the bike would hesitate, jerk, go a little then want to stall. My first thoughts were a clogged jet passage so i blew everything out with air and then carb cleaner several time, removed and inspected all jets as well as passages. I then thought it may be related to fuel flow. I drained and removed the tank and found some rust/debris in the upper petcock filter i removed and cleaned the filter as well as completely disassembled the petcock. I tested before the cleaning and after with little improvement, i get anywhere from 200-220 ML in 1 minuet from the fuel line from the carb as well as when tested flowing through the carb with the bottom hex nut of the float chamber removed.

Before i switched out the pilot jet i had a 30 in and it ran well. Pick up was strong from a stop, no hessitation and idled well, it was just a little rich. so whatever my problem is it happened during the time when i removed the carb and put in the 27.5 becuase after i switched that out and put the 30 back it i still have the same problems as i did with the 27.5,

My thoughts are that i may have unknowingly bummed or moved the float and this is the cause of my problems.

I have a battery that is fully charged and is less than a month old. I cleaned my points, readjusted my gap and checked/re-set static timing.

After trying several float heights last night with no progress i lowered the chambers (pushed down on them with the carb in hand upside down) to about 24MM. i put it back on my bike and i cant even get it to kick over now. I have spark and a good amount of battery power.

when you say "if you set the float at a lesser height the bowl will fill more and it will have a tendency to run rich" . do you mean lesser as the float will sit closer to the bottom of the float bowl or closer to the top of the carb/needle assembly?

I have checked several times that i have the correct pilot jet in, i know those numbers are small but i made sure i didnt make a simple error and end up with a 10 in their or something.

Thank you for the help.

[Kevin Mahoney]

I have to admit that given the circumstances it would certainly lead you look at the carburetor. I had this happen once when I changed a main jet. Turns out that when I screwed it back in the brass piece that the needle goes in and out of was out of place. took me a while to find it.

I meant that if you have the carb upside down and are setting the float and you set it lower than 25mm it will tend to run rich because when the carb is in the proper position upright the flow of petrol will be cut off at a higher level. You might want to check and make sure that the float is not hanging up on something when you put the bowl back on. Also if that carb had a plastic spacer between the carb body and the float bowl make sure that it isn't missing. (You will have an extra part lying around and it is white). If it was not there in the first place don't obsess. Some had them some didn't, depended upon the depth of the bowl.

Make sure you put a good in line filter in your petrol line. 1999 tanks were not lined with a rust and corrosion preventative and were prone to rusting.

Check the rubber intake manifold, They are a wear item and were really prone to a short life on 1999 models. The new ones wear out, but they are made of much better rubber. Sometimes it is hard to see the cracks in them. Often times they are under the clamps and not obvious.

About 1999's
Prone to regulator problems. In 2000 they put Motorola components in the regulators and that was the end of the problem. Alternator is marginal but OK. Prone to electrical issues that are caused by the old style Bullet connectors, one you go through them it is fine. The washer underneath the bolt that holds the distributor cam is a bit small and sometimes it causes the bolt to prevent the advance mechanism from turning the points cam. Easy to spot, easy to cure. Sometime the advance weight hit the underside of the condenser which is also easy to see. Occasionally hard to seal the oil lines going to the head. The answer is to put an extra washer between the head and the underside of the oil line. some of the Banjo bolts were just a wee bit too long.
Will only charge in the second "on"position of the key. Sometimes the blue wire leading from the ignition switch gets disconnected because when you put the connector together the lead pushed back and is not making contact. A bit more difficult to see. If they blow fuses take the left and right handle bar switches off and make sure that the solder holding the wires to the switch is not grounding on the handlebars (happened a lot), a bit of electrical tape cures this. Make sure the wiring harness leading to the taillight is tucked up to the tabs under the fender. Clean the ground behind the taillight once in a while. If you have shifting problems, first check the chain adjustment and then have a buddy hold the bike up while you slide under it with a flash light and see if the linkage is fouling the frame, If so grind the "banana" shaped arm so that it doesn't.
The key is to have the center stand up while you do this and look VERY carefully.
The third thing is to adjust the clutch as "tight as you dare".  there is more about shifting but that will keep anyone busy for a while.

[JordanMix]

Kevin.

Thanks for the reply. hopefully i can sort it out this weekend and get back on the road. i fairly certain it is my float height, everything else seems to be eliminated. I will reset it tonight and hopefully the monsoon we are having now has ended so i can get a road test in.

[JordanMix]

took care of it this weekend.... i had the float set to low. I guess i really didn't understand the technique for measuring the float height. I reset it properly this weekend and everything seems good. i am still getting black plugs at low speeds but with a 27.5 pilot and clip in the second from lowest position i am afraid to go any leaner. I think i am just going to leave it at that.