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Discussion Starter #1
ok so i cleaned out the carbs, new pilots, meticulously cleaned everything else etc... everything ran fine. went for a little ride around town.

after about 20 miles or so, some issues started appearing:

1. couldnt go WOT, or else it would bog after 5k... if i was slow and smooth though, i could rev all the way to redline with no problem. fuel level too high?

2. as i was sitting at a red light, the idle slowly started dropping. i could blip the throttle and keep it going. once i got home i just let it idle in the driveway and idle drops, drops and then it dies. then it didnt want to start after that. it would crank but not fire, unless i opened the throttle all the way. any ideas about this?

i have my pilot screws set at about 2.75 turns out. i did 2.5 as ppl on here suggest... sounded like it idled better if i went that extra 1/4 turn.


let it sit for a bit, when i went back down, i turned the key on, then flipped the switch to run, and as i did that (before i hit the start button) it backfired! kinda scared me. not very loud, but loud enough to make me jump. whats the deal with that?

is my fuel/float level too high/low?
 

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Lets make this #3
Float valves leaking possiable float level too high.

woops that's a #2

FOG
 

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Discussion Starter #3
just went down there to check it out. fired right up on the first try. however i did notice a small puddle of gasoline on the left side of the bike under the front. :( it wasnt dripping, but it was wet. it is coming from the little hole in the side of the cyl head.

where does this hole go?

when the bike was running, i could visibly see some smoke or steam or some sort of whiteish vapor coming out of the hole on this side, however not on the other side.


i checked the fuel inlet needles when i cleaned the carbs. they were in good condition. no grooves or scratches in the needle part. the rod worked fine too...

the valves are not serviceable on these machines correct? IIRC they are pressed into the carb body, instead of being screwed in, and able to remove ::)
 

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True but the needles are replacable, they have rubber tips that do wear. Also junk in the line from the tank will either plug shut or block ope a float valve. be sure to backflush this line to the tank and fit an in line filter.

The holes in the head are drains for the plug sockets. no gas in there The gas came from the afore mentioned leaking float valve overfilling the carb bowl and running out the overflow. On the left only because the bike leans that way on the side stand , making the vent lower than the top of the carb throat. If parked on the center stand the same failure will flood into the cylinders and could cause Hydraulic lock.

BTW your petcock is leaking too.

FOG
 

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Discussion Starter #5
thanks for your reply.

FOG said:
True but the needles are replacable, they have rubber tips that do wear. Also junk in the line from the tank will either plug shut or block ope a float valve. be sure to backflush this line to the tank and fit an in line filter.
in line filter... check. already got that. will backflush the line.

The holes in the head are drains for the plug sockets. no gas in there The gas came from the afore mentioned leaking float valve overfilling the carb bowl and running out the overflow. On the left only because the bike leans that way on the side stand , making the vent lower than the top of the carb throat. If parked on the center stand the same failure will flood into the cylinders and could cause Hydraulic lock.
had the leaky valve with the first set of carbs when i bought the bike. got new (used) carbs and that cleared up that problem.

SOMETHING wet leaked from that hole. check out the pics i took here:

http://s149.photobucket.com/albums/s72/harperlou/bikes/

you can see the hole i speak of, and that there has been something wet on the fins (as evidenced by the discoloration in the dust/dirt on the fins. i took a pic of the other side for reference.

i touched the bottom most fin, and there is something wet (smells like gas)... thats the pic with my finger.

additionally, you can see the spot on the floor where the gas was. in the pic its the largest spot on the floor just to the front of the side cover. this morning when it was a bit wetter, it smelled like gas too. correct me if im wrong, but if it came from the overflow, wouldnt it be more under the carbs?

i took a pic of that too, and as you can see, its bone dry under there.


BTW your petcock is leaking too.

FOG
ill check it to make positive, but im pretty sure that it is not. i had the tank off the bike the last week while i was getting the carbs sorted out. tank has about 3 gallons in it, and i experienced no leakage from the petcock during this time. the tank was in about the same position it is on the bike, on a saw horse.
 

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Discussion Starter #6
also, what was that vapor i saw coming from that hole when the bike was running?

if you cant view those pics, let me know, and ill post them in here or something.
 

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IIRC, i asked fog what the holes were designed to do and he told me that they are there to evacuate water from that area. could it be water dragknee?
 

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Give the man a food pellet.

FOG
 

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Discussion Starter #9
it could be, however it had a very strong gasoline smell. i didnt test the flammability of it though... i will do that when i get home :) additionally, the spot on the ground seemed much more like gas than water, the way it spread out over the area.

not really sure how any water would get in there either... let alone the amount that was on the floor...

the bike hasnt seen any rain this season at all, and i havent washed it either.


no verdict yet on the vapor i saw coming from there.

im going to take the tank off when i get home and double check that spark plug to make sure its in there tight.
 

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The two coolant pipes that fit into the head are common leakers,that water ?antifreeze runs into the spark plug hole and drains out the fins. when the engine get hot it boils that coolant and you see vapor.

FOG
 

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Discussion Starter #12
got it fixed... the spark plug was loose. how? i have no idea. fairly sure that i tightened it last time i was in there... maybe i had too many beers and forgot lol. cleaned it off, tightened it down. voila! no more gas, no more vapor.

still having some trouble going to WOT... but nowhere near as bad. if im smooth with it, and slowly open the throttle, it builds RPM no problemo. but if i try to flog it, and go from 1/4 throttle to WOT in one twist, it kind of bogs down at first and misfires a time or two, then it goes fine.

going to do some carburetor adjustment tomorrow. id do it tonight, but i do live in a fairly densely populated area, and i dont think the neighbors like the sound of the bike. (except for the guy 2 doors down with a fireblade :) ) i try to keep my working on the bike to during the day, since i work at nights anyway. most people around me arent home during the day.


FOG, have you ever used a gunnison colortune? my buddy has one, and was extolling the virtues of it to me. if youve never heard of that, basically its a clear spark plug, with a mirror attachment, that lets you see the actual flame burning in the cylinder. you can use the color of the flame to adjust the mixture to pretty much perfect... ive never used one personally, but i have an XJ650 also, and on the list for that bike, they pretty much swear by them... just wondering if you've heard of or used them, and if they are actually as good as people say.
 

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What kind of mods do you have on your bike? I ran into about the same problem. The mods I have on my bike are,sarachu slipons,and a K&N filter(for motor upgrades at least). I had FOGs airbox mod but it made to much of a pressure drop behind the carbs and would'nt raise the slides properly. It was the same kind of problem that your describing,I would hammer the throttle real quick to WOT and it would fall on its face for a second or two and then it would go,but if I was easy on it,I wouldn't have a problem. I guess I got things freeflowing a little to much for FOG's airbox mod. I just covered up the hole and it runs great,and no this isn't a bash towards FOG's airbox mod. His airbox mod works wounders on most of the EX's out there( it worked great on my buddies) but it just didn't work on my bike with the mods I had. If I would of had my stock pipes on,I'm sure I wouldn't of had a problem.
 

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Geez... I can't sleep.

WOT via Google also means:
Wheel of Time (book series for young adults)
War on Terrorism
Web of Trust (email certification scheme)
Water on Tap (EPA term)

And more. But if you have real courage go here: http://www.wot.net/
 

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scoobywrx05 said:
What kind of mods do you have on your bike? I ran into about the same problem. The mods I have on my bike are,sarachu slipons,and a K&N filter(for motor upgrades at least). I had FOGs airbox mod but it made to much of a pressure drop behind the carbs and would'nt raise the slides properly. It was the same kind of problem that your describing,I would hammer the throttle real quick to WOT and it would fall on its face for a second or two and then it would go,but if I was easy on it,I wouldn't have a problem. I guess I got things freeflowing a little to much for FOG's airbox mod. I just covered up the hole and it runs great,and no this isn't a bash towards FOG's airbox mod. His airbox mod works wounders on most of the EX's out there( it worked great on my buddies) but it just didn't work on my bike with the mods I had. If I would of had my stock pipes on,I'm sure I wouldn't of had a problem.
I just got around to reading your post. It would seem you misunderstand the workings of the CV Carb. when you suddenly open the throttle the speed of the airflow over the jet bridge drops. this causes the vacume that lifts the slides to also dorp and then the slide drops. this action is self servoing and the result is the speed of the airflow across the jet bridge in the carb (Venturi) in relativlly constant. I'll submit that you have not properly adjusted you pilot screws or have partilly blocked pilot jets. Your plugging the airbox hole increased the vacume in the entire intake tract and allowed atmospheric pressure to force more fuel into the airstream. compensating for you (blocked jet).

FOG
 
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