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Discussion Starter #1
well i just joined and have been reading a lot, you guys do have a lot of good information.
I have a 93 en500 and i just got a 94 vn750. the 750 was a friends friend who had it sitting in his garage for 10 years and it only has 1300 miles on it.
i took the carbs off and cleaned them out, actually there wasnt much to clean because they had apparently drained the bowls prior to storage.
i got the carbs back on and the bike starts perfect and idles fine but only when the choke is on all the way. if i let it warm up and then push the choke off the motor will just die. if i hold the throttle open and take the choke off then it will stay running untill i let off the throttle, i also have the idle adjustment screw in all the way(highest idle). i can ride it but it surges a lot and it is difficult to hold a constant 60mph but if i keep the revs really high(5000+) all the time the motor runs awesome.
and the other day i took it for its first home-work-home trip (only 25mi) and i went through over 3 gal of gas, it was full when i left and i had to get gas on the way home. fuel is not coming out of the vent tubes and when i had the carbs off i blew in the fuel lines and checked to see if the little seal was still good and it was.
i am totally stumped, the 500 runs perfect so i never have to do any carb maintenance so i dont know much about carbs. anyone have any ideas as to what could be wrong?
 

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Did you change the spark plugs before you took her on the road. I'd suspect bad plugs after 10 years in storage.

Another thought if the carbs looked clean is rust in the tank. You might pop the cap and take a look.

The symptoms sound a lot like clogged high speed jets though, try running some seafoam and see if it helps.
 

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Absolutely! Give it a good dose of seafoam, as much as a half can in a full tank, run it for a few minutes and then let it sit for a day or two. See if it helps clear it up.

While you are waiting, it would be a good idea to replace all your vacuum lines and fuel hoses. That stuff is supposed to be replaced long before 10 years so it wouldn't hurt.
 

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Discussion Starter #4
i have a bunch of seafoam in there and i checked the plugs and they looked fine. one thing they did do was change out the fuel every couple years and added stybil so there isnt any rust in there. i did replace the fuel lines and checked the vac lines also. do you know how to explain the 8mpg?
 

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I know you checked the needle and seat thats attached to the float but did you check the floats to see if they were able to float sometimes a float can get a pin hole in them and fill with fuel letting them sink allowing fuel to leak.Sometimes into the cylinders past the rings and into the crankcase.Just something to ponder...........................
 

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Discussion Starter #6
well maby i will have to take the carbs off again (curses in disgust) and check the floats, and i did smell the oil and it still smells like oil so i don't think much gas leaked past the rings but the plugs were supper black and fuel smelling.
 

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and the Adventure Cycle
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Did ya do anything with the airfilters? (check & clean, quite possibly replace)
They have a tendency to dry out and start crumbling into tiny pieces.
 

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Discussion Starter #8
i did forget to mention something, during all of this i have only just had those little curved intakes on the carbs, not connected into the airbox. would this make the bike not idle right? i plan to put k&N's on it but if i cant get this this bike to run right i am just going to have to convert it over to fuel injection becuase efi is way easier then this carb crap. if it goes that far i will be using megasquirt.
 

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i also have the idle adjustment screw in all the way(highest idle).
If you mean the a/f screw on each carb then they should be turned OUT, 2 - 3 turns.
 

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i did forget to mention something, during all of this i have only just had those little curved intakes on the carbs, not connected into the airbox. would this make the bike not idle right? i plan to put k&N's on it but if i cant get this this bike to run right i am just going to have to convert it over to fuel injection becuase efi is way easier then this carb crap. if it goes that far i will be using megasquirt.
You mean the hoses that run from the exhaust valve to the reed valve covers?? That should really only affect the exhaust, not the carbs.
 

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i did forget to mention something, during all of this i have only just had those little curved intakes on the carbs, not connected into the airbox. would this make the bike not idle right? i plan to put k&N's on it but if i cant get this this bike to run right i am just going to have to convert it over to fuel injection becuase efi is way easier then this carb crap. if it goes that far i will be using megasquirt.
:doh:The airbox and filters have a huge impact on keeping these things running rich enough. If you are going to do the ear shave (run it with out the airbox and ears) you will have to rejet your carb.
 

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I was having the very same problem with surging around 60mph, between 3500 and 4000 rpm. The plugs were black so after taking care of them the problem went away. Didn't have the idling problem though, so I'd back the screws out a couple turns.
 

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Discussion Starter #13
from what i have read some of you think i meant the a/f screw is turned in all the way but it is the idle speed adjustment that i have fully in. i bought 2 sets of cheap plugs and ran the bike for about 10 miles on each set and they were all black. i dont know how this can be, i dont have the carbs hooked up to the airbox, they are just sucking strait from the atmosphere, shouldnt it be running lean?
i think sucker punch to my pride and a trip to the dealer is in order. it will be the first time i have taken a vehicle to a mechanic.
 

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Man that's a tough one. You're obviously running way rich, but the carbs should be getting plenty of air. You prolly backed the idle down by now. Sounds like the gas is just pouring in though, gotta be the floats. Keep us posted.
 

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"ya can't live forever"
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Take the carbs off and inspect the floats, clean 'em up and re-install. Make sure they are set at the right height. R&R the pilot and main jets clean them up well. Use some small monofilament fishing line to run thru the jet orifices.

This ought to straighten you out.
 

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Check your vacuum line off the petcock. It might be leaking gas through the vacuum line via a bad diaphram in the petcock. I've seen it happen.
Also, make sure you have your fuel lines routed correctly from the petcock and not crossed with a vacuum line.
 

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Discussion Starter #18
well after 2.5 months in the shop and $400 later the bike lives.
the jets from sudco were back ordered like a mofo. the bike is awesome now, way faster then my 500 vulcan. thanks to whomever went through the trouble of finding the proper size jets because if it were not for them i might not have my bike until next year.
thanks
-jake
 
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