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Discussion Starter · #1 ·
I've got a problem that I know I've seen on this board several times before. Cruising at high speed (or high RPM), the bike starts to lose power and it eventually dies, in a few minutes it's better, etc. Well, this has gone one step further than anything I've seen here in the past - The other day I was on a 120 mile road trip and I got about 40 miles from home and said problem occurred. So, I did what I always do: pull over and wait for a minute or two. This did help for about 15 miles or so. Then it started again. And again... with a total of almost 15 stops along the way and the intervals kept getting shorter as well. On the return trip the next day, the bike did fine under 7000 RPM for a while, then I had to limit it to 6 and then 5 before I finally got home. I rode it like grandma and NEVER revved it over 7K even one time coming home nor did I open the throttle any farther than I had to. This problem is driving me up the damn wall!!!!! In addition to that, I just had my carbs synchronised and the bike now runs hotter (too lean?). My thoughts on what might be wrong:
1.Bad fuel filter? this bike has 17000 miles and I don't know if it's the original filter.
2.Bad fuel pump?
3.Bad coil/black box/plug(s)/plug wires?
4.Dirty jets/stuck float/perking gas in bowls?

Also, what fuel pressure should this pump push so i can test it? THANKS TO ANYONE THAT CAN HELP!!!!! If anyone has any similar experiences, please let me know!!!!!

Derick

My Bike
 

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I said this quite a few times, but yors definatly sounds like crud in tank. If you have less gas in your tank then the bike stopping is more often that gotta be it. I would tank tank off get some kerosene or something to put in tank remove fuel pump get gasket filter if possible take hand squeez in and rub tank after this put on pump put kerosene in lot more and either if you got drink milk and pretty strong slosh the gas aorund very rapid then empty out contents then do again then i am not sure if you would but i would take some water and do the same thing then drain set tank aside let dry or just throw some gasoline in (watch it very dangerous if you didn't know) then empty contents. Put back on bike run it see how it does. Be sure you put gas in
 

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Yeah i still would pull it because the pump is well below the tank and it would form down there that is just best to look look for that orange stuff (you already know though)
 

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did you check the air vent in the tank like john (gsxrfreak) said ???
it just sounds so much like that.
is there any water in the tank finding its way ?? have you drained the float bowls ?? if there's water in there, you'll see it in a clear container seperated from the fuel.....just ideas.
 

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Discussion Starter · #5 ·
Well, I just ordered a new filter and gasket kit from my dealer and while I have everything apart, I'm going to check my float bowls and try and clean out my vent with some carb cleaner. Also, as I said in the original post, does anybody have info on the fuel pressure that bike's supposed to be running? I'd like to test it and see if the problem is in the pump itself. It always seems to sound fine while it primes, but I'm not sure if it starts to get "tired" after it heats up a little. I've seem electrical components that don't work as well when they're hot and I was also thinking that maybe some of the pump's internals are gummed up from 17000 miles of crap pouring through it? Thanks for the help guys...

Derick
 

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hey do a search somewhere it is stated i done forgot Jeff might remember off hand if my memory serves right it was 6-8 psi don't hold me to it. Book ought to tell you also
 

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Discussion Starter · #7 ·
Well, it could be crud, but I've actually looked down into the tank with a little gooseneck light that I used to shove down in the door cavities of cars, and I found nothing to cause alarm. everything looked fine (and believe me, I've seen nasty tanks before) and I also know it's not my vent cap, because I can open and close it when the problem occurrs and it has no effect. Any other ideas?

Derick
 

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If I were you I would pull the tank off, then pull the fuel pump and inspect it. The fuel filter is pretty expensive to replace, I actually have one from my bike that I replaced but it is still good I never had any problems I just had the pump out and figured why not since I got the new one cheap (retail is something like $53 or something!).

you should be able to blow out any crap in the filter possibly, I would check all the fuel hoses as well. Totally seems like something fuel realted, not electrical. good luck
 

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my haynes manual doesn't state an operating pressure for the fuel pump as you ask for, but says to test the actual fuel flow output in litres (discharge rate). it looks well fiddly but says you should have a minimum of 1 litre per 60 seconds flow. that tests the pump which should be ok though.
i still say check the fuel tank breather hose though !!!!
 

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im having the same problem with myn 2003 gsxr 750. i cleaned the tank and fuel pump. did the whole por15 sealer in the tank. cleaned the injectors, rail, throttle bodies and installed new plugs. it starts and sounds great. if i rev it up it will give me a high rpm at first start. if i hold the throttle the rpm will start to drop. if i keep flipping the throttle back the rpm gets lower and lower. i shut it down and let it sit for awhile and the rpm is high again then it will drop and drop. i also added some sea foam that is suppose to help clean out everything and its still doing it. im thinking its not getting the right amount of fuel. what is the output fuel pressure supose to be and how can i test it. i need help please
 

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My Clymer manual doesn't give a psi, it measures in liters per minute. There doesn't need to be a lot of pressure just as long as the bowls stay full of fuel while being ridden. Check your air lines in front and back of the airbox and motor while your at it. I had a problem with an air line and it did a little of the same thing as your experiencing. Check everything......
 

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Sounds fuel related.
Thing to do are:
1-Remove fuel pump and check filter for obstructions
2-Check pump for proper operation (6-8psi)
3-Check tank for rust or sediment at bottom
4-Flush tank
5-Lather-rinse-repeat
6-Install external in-line fuel filter
7-Remove carbs and inspect/clean as needed
8-Reinstall and check fuel valve (petcock) for proper operation
9-Check for obstructed breather lines
10-Enjoy
 

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i would think if you had to treat the inside of your tank due to rust then you have rust in the pump.. try taking the pump off the pump and sending unit and soaking it in seafoam. you could even run 12v to it and let it pump some seafoam threw it.
 

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i would think if you had to treat the inside of your tank due to rust then you have rust in the pump.. try taking the pump off the pump and sending unit and soaking it in seafoam. you could even run 12v to it and let it pump some seafoam threw it.
If the tank is so badly rusted that it requires treatment/sealer, just replace it!
 
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