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Author Topic: rebel 250 problem  (Read 1661 times)

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Offline muttblbc

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rebel 250 problem
« on: February 28, 2008, 01:46:14 PM »
Ive been working on a 1985 rebel 250 and im stumped, i got it with a pod filter cleaned the carb to get it going started it up and it will idle but when i give it any throttle it severely dogs the more throttle i give it the lower it drops till it will just die. i went through the carb several times kept having the same problem so i put the air box and origional air filter back on, same problem but now more so it dogs at the slightest movement ofthe throttle and will die at less than an 1/8th turn. im not sure what to do next as the needle height and float position are non adjustable. (and ive tried two different rebel 250 carbs on it and adjusting the air fuel mixture screw in and out ) everything is back to stock EXCEPT it has a set of 2 into 2 jardine pipes on it, but would the exhaust effect it that drastically? anybody have any ideas?!
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fuzzybutt

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Re: rebel 250 problem
« Reply #1 on: February 28, 2008, 06:10:37 PM »
it needs bigger jets, badly
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Offline 333

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Re: rebel 250 problem
« Reply #2 on: February 28, 2008, 07:07:57 PM »
What color are the plugs?
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Offline heffay

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Re: rebel 250 problem
« Reply #3 on: February 28, 2008, 08:11:59 PM »
its a rebel.   8)

oops... sorry, was that out loud  ;)  jk

fuel on?
recent carb cleans can turn out to be recent dislodge carb gunk into important passageways. 
never rejetted for aftermarket pipes?
was this a well running bike before the pipes?
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Offline muttblbc

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Re: rebel 250 problem
« Reply #4 on: February 29, 2008, 01:20:21 PM »
it was never jetted for the pipes, the plugs are definatley dark, and i dont know if this thing ever ran well before it was given to me, after writing yesterday i let it fully warm up, once its at operating temp if you give it throttle itll rev up but theres a couple second delay between the throttle getting twisted and the effect, and then it races really high. the 85s where cdi but could it be a timing problem?
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Offline heffay

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Re: rebel 250 problem
« Reply #5 on: February 29, 2008, 01:24:31 PM »
new fuel filter?
how's the petcock? 
sounds like a fuel issue.
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Offline muttblbc

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Re: rebel 250 problem
« Reply #6 on: February 29, 2008, 01:31:10 PM »
right now i have the tank off and im running gas staight from an auxillary plastic tank through a clean filter.
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Offline heffay

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Re: rebel 250 problem
« Reply #7 on: February 29, 2008, 01:49:05 PM »
i'd just go buy some bigger main jets.  cheapest and quickest way to find out if thats what it wants.  sounds like it is.
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fuzzybutt

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Re: rebel 250 problem
« Reply #8 on: February 29, 2008, 02:15:21 PM »
are those cv carbs? is it possible theres a pinhole in a diaphram? i've never dealt with cv carbs so this is just a wild assed guess
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Offline muttblbc

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Re: rebel 250 problem
« Reply #9 on: February 29, 2008, 02:58:58 PM »
yes they're cv, the diaphram was the first thing i checked and it was fine, the thing that i noticed was that the carb dosent have the spring that most cv carbs have between the sliders ans the cap, but this was true for two different carbs i disassembled, but i dont see a spring on the parts schematic. also it seems to me that the all the symptoms point to the bike running incredibly rich, wouldn't i want to install smaller jets?
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Offline heffay

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Re: rebel 250 problem
« Reply #10 on: February 29, 2008, 03:03:19 PM »
well, if you have a racing idle you could also not be getting a good seal on your boots. 
my opinion... plug color and symptoms seem to contradict. 

might be getting a little oil blow by on the cylinders to blacken up your plugs... damn there's so many possibilities.
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Today: '73 cb350f, '96 Ducati 900 Supersport
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Offline muttblbc

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Re: rebel 250 problem
« Reply #11 on: February 29, 2008, 03:25:44 PM »
additionally i just talked to the guy who gave me the bike and he says the jardines are aftermarket pipes made specifically for the rebel.
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