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sputters, but barely runs.

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  #11  
Old 03-04-2006, 01:29 AM
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Default RE: sputters, but barely runs.


ORIGINAL: flyboy110b

No fuel pump on this one.. its gravity fed. About the pilot jets. The opening hole is the smallest i've ever seen.No where near the size of the main jet. Its only the size of a pin head, BUT i can see through it, and I can blow through it.. I don't know what rpm range is it supposed to work for, but it work up two about 3k. But when i blew on the fuel line to give it a little more pressure (too much would kill it) it runs fine. i don't really know about it,so I've got the carbs off and in my car. I'm gonna take it to the dealership and see what they think.. too bad i don't have the money to pay them to work on it.
Did you try the af screws?
Let us know what the dealer tells you and good luck.
 
  #12  
Old 03-04-2006, 03:15 AM
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Default RE: sputters, but barely runs.

Af screws? dont know what that it.
So i took my whole carb assembly to the dealership to get some advice. Jets are clean. Two of the needles were a little scuffed-up to i did my best on them with a wire-wheele. diaphrams are all good.. Before, one wasn't going up very well. Did one last cleaning of the carbs. I put it back on the bix without the airbox to i could adjust the pilot screw.. This is only for idle, right? anyways, 2.5 turns out was okay, 3 it would bog down, so they're set 2 turns out. After i let it warm up, it could rev it up to 8k +. So i put the airbox back on.

Now it was time for my first test drive. i put it in gear, at least what i thought was 1st, may have been 2nd, i'm still getting used to it. Its a little hard to get it in and out of gear. So i coast down my driveway and into the street. I live on a big hill, so i went up just in case something happened so i could coast bask home. It didn't do too well. There wasn't a whole lot of power. In fact, about 4k rpms or lower wouldn't get me up the street. I coast back home, turn around and try it again. This time with a little more success, i got all the way up the street staying around 5k. That was fast enough, because i live on a one-way street, which is has a hill on one side and a drop off with lots of oaks on the other. Towards the top, it was bogging down again. so I stopped and tried reving it a little.
It would either kind of sputter and gain hardly any rpm, or it would die.

now I'm back at home. There's less than a gallon of gas in the tank. That could be it. I know there's supposed to be a filter and a hose or two i think on top of the fuel tap inside the tank.. but its not there.. so that could be it..
anyone has some suggestions..

hey, if anything, i got it up the street and back.
 
  #13  
Old 03-04-2006, 04:09 AM
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Default RE: sputters, but barely runs.

AF screws- Air Fuel Mixture. You have them at 2.5 have you tried to turn the in more to say 2 or even 1.5.

Your gears are down 1 for 1st and then all up. Just through that in because you sounded a little unclear.

What is the model and year of your bike please?
What mods does it have? Not sure if you posted it earlier I did not check, but post it again please.

Did the dealer do anything to your carbs or tell you where the af screws should be?
 
  #14  
Old 03-04-2006, 05:16 AM
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Default RE: sputters, but barely runs.

Oh, air/fuel... okay, those are the ones under, on the engine side right. I guess i can try and adjust them some more.. the thing is, i don't have a screwdriver to fit it with the carbs still on the bike. before i was adjusting them with the air box off, and the carbs just placed on the inlets.. i have to find the right tool.

so the gears.. all the way down is 1st, and the rest up? i used to have an old yz, its nothing like this.. i'm a noobie for sportbikes.
the Bike is a 1990 zx750 F4.. its not a ZX-R, no R... and everything on it is stock.
 
  #15  
Old 03-04-2006, 06:05 AM
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Default RE: sputters, but barely runs.

Okay got the model and will do a little research.

As for as the air/fuel mixture screws go if everything on the bike os stock and the carbs have not been rejeted they are not accessible with out drilling out a brass cap and are located near the bottom of the float covers. If you can see the four screws than they have already been drilled out. If not they should appear as if there is a brass plug covering them.

You described this: "air/fuel... okay, those are the ones under, on the engine side right." Can you take a picture of what you have been adjusting?

There are 3 screws between the crabs with springs on them, 1 between each carb. Have you turned these at all? They are the synchronization screws and if they have been adjusted a lot it will affect the bike. You need special gauge to properly sync the carbs. The shop should do it for about 45.00.

You are correct about the fuel pump I did not see one listed on the parts list.

The gears are 1 down and 5 up. Neutral is between 1st and 2nd.

What did the dealer tell you about the carbs?
 
  #16  
Old 03-04-2006, 06:30 AM
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Default RE: sputters, but barely runs.

Sorry about the fuel pump question. My '90 ZX-7 H2 has one. My a/f plugs were tin and not brass though.
 
  #17  
Old 03-04-2006, 08:35 AM
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Default RE: sputters, but barely runs.

Yeah, the covers on the pilot screws were already off. I'll get a picture up asap.. its just i have a crappy internet connection.
I've done my best to tune the carbs by myself.. set all the pilot screws to the same number of roataions. as for synching them,
I eyeballed it.. the vaccum hole inside the carbs make a good reference points.. though, when i can get it running well enough to
drive t the dealership, i will have that done.
Thanks for the info about the tranny. I was way off!

here's a quesion for you guys: I've heard that if you let a motorcycle batter die, its pretty much dead for life.. that it can't hold a charge.
is this true? because my batter was dead long before i got the bike. and i've charged it up and drained it twice just trying to get the thing started before.
 
  #18  
Old 03-04-2006, 06:00 PM
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Default RE: sputters, but barely runs.

age will kill the batt, I have recharged mine a number of times. If you were in the wrong gear, it may explain why you could not get the bike to run up hill very well.


**Spelling Edit**[&o]
 
  #19  
Old 03-04-2006, 09:12 PM
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Default RE: sputters, but barely runs.

Right on, dude. From when you first started, you made a lot of progress so far!! Keep it goin' See, that Corona helped, huh!!!
 
  #20  
Old 03-05-2006, 12:40 AM
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Default RE: sputters, but barely runs.


ORIGINAL: BigRig18Wheeler

Right on, dude. From when you first started, you made a lot of progress so far!! Keep it goin' See, that Corona helped, huh!!!
Like this?

[IMG]local://upfiles/346/8AFF4965716E4FA2B4E55C3101E8DAAD.jpg[/IMG]

[IMG]local://upfiles/346/673DA4AD4D9F40E3B7AAC610AA1AD373.jpg[/IMG]
 


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