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Discussion Starter · #1 ·
ok just a background first
its a mc 19
i took my carbs out last week to clean them but ended up taking the carbs to a mechanic as a lot of the screws were badly chewed up and im not good with easy outs
he gave it a clean and asked me to put them back on the bike and bring it to him to balance the carbs
i put it back on yesterday and did a couple of laps in my garage(i live in an apartment) it was running fine

just took the bike today to fill up before i take it to the mechanic and it was acting strange
it idled fine, then i started riding and at the first set of lights when i stopped the bike suddenly started idling at 10k, if i shut the throttle while idling the engine would turn off
the throttle didnt seem normal anymore, it would snap back properly but i could never "shut the throttle" more when it was idling if you get what i mean (twist it forward)

at the service station i loosened the idle adjuster but 6k was the lowest it would go

is a carb balance gonna solve this or is there something else wrong here?
thanks
 

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Discussion Starter · #3 ·
theres only one way it goes on
well theres 2, but if it was the other way then wouldnt the throttle work in reverse?
ie decrease speed when twisted back and increase when twisted forward

so i think its on fine
unless theres something i missed
 

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Yes, there's only one way for it to be working as it is. If it was attached the wrong way around it can't pull the lever at all.

With my limited knowledge it sounds like there might be tension in the cable when you're not even on the throttle. My first step would be to take the air box off and check that there is no tension in the throttle cable that is pulling the lever when no throttle is being applied.

You only took off the carbies, so it wouldn't be anything too technical.
 

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check how your throttle cables have been routed around the airbox, have seen this issue before.

also, check that your chocke isnt been held open and that all linkages on your carbies are free and moving
 

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Discussion Starter · #8 ·
francisz said:
what do you mean by "shut the throttle while idling"?
i mean when the bike is idling, i can close the throttle more
like twist it forward to slow it down and then if i twist it more the engine turns off


shane said:
check how your throttle cables have been routed around the airbox, have seen this issue before.

also, check that your chocke isnt been held open and that all linkages on your carbies are free and moving
i'll take the tank off and see if the cables are routed around the airbox
also what do you mean by linkages?

thanks
 

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+1 on what Shaneo said, also, check to make sure you've got 2-3mm of throttle freeplay, if you don't then the whole system can lock up when it gets hot.
 

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viper33 said:
francisz said:
what do you mean by "shut the throttle while idling"?
i mean when the bike is idling, i can close the throttle more
like twist it forward to slow it down and then if i twist it more the engine turns off


shane said:
check how your throttle cables have been routed around the airbox, have seen this issue before.

also, check that your chocke isnt been held open and that all linkages on your carbies are free and moving
i'll take the tank off and see if the cables are routed around the airbox
also what do you mean by linkages?

thanks
theres a common bar that transfers the movement from the cable to each carby. make sure everything is free and all carbies are moving at the same time
 

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Discussion Starter · #12 ·
shane said:
theres a common bar that transfers the movement from the cable to each carby. make sure everything is free and all carbies are moving at the same time
ah right....thanks
do i have to take the carbies off? coz id rather not, its a fucken pain taking them off and putting them back on
 

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to check the freeplay grab the throttle, move it gently backward and forward from fully closed. You should feel that there is a defined engagement point a few mm away from fully closed, if you don't feel that then you need to loosen off your throttle return cable adjustor a little.

As per what Shane said, you'll have to pull the carbies off to fix the problem no matter what it is.
 

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Discussion Starter · #15 ·
ok thanks
i'll do that today

Drew said:
if you don't feel that then you need to loosen off your throttle return cable adjustor a little.
the return cable adjuster?
would this be next to or on the pulley thing which holds the 2 wires?
and how do you go about adjusting the cable?
 

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The return cable adjustor attached to one of the two wires, its attached to the carb and its on the end of the cable which closes the throttle.
 

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Discussion Starter · #17 ·
ok i'll have a look in an hours time and see if i can find it, thanks
also is it alright to use vaseline on the boots as grease to put them back on?
 

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Its probably better to use something like dishwashing detergent, because that will dry out in a couple of days and you won't have carb boots which want to randomly slip off ;)
 

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Discussion Starter · #19 ·
hahaha true, didn't think about that

i'll probably get some grease, shops were closed last time so had to use vaseline
 

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Discussion Starter · #20 ·
ok took the carbies off today
the cable was a bit loose, hence im able to close the throttle more when idling(twist it forward)
the choke wasn't being held open and the cables go directly underneath the airbox
that is how they were when i first took the carbs off

i couldn't find an adjuster or anything to tighten it the cable
so i sat the top cable's screw in the bottom slot and the bottom ones in the top slot
not the cable, the screw with the nuts on it
it seemed perfect except it wouldnt spring back sometimes when i let go of the throttle
but thinking id be able to ride this to a mechanic and get him to fix it, i put the airbox back on and the tank and the throttle suddenly got a whole lot tighter
i had to use a lot of force to twist it
using the throttle when the bike was turned right was impossible, even if i used two hands to twist it

plus there was a burning smell coming from somewhere
couldn't figure out where but the higher the rpm the more the smell
turned it off before i stuffed up anything else

now im here for advice
 
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