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Cold starting issues


Sk93
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Ok.. I'm PRETTY sure that this is an overfueling issue... but here goes :)



Firstly, I am by no means a mechanic. I'm ok when it comes to cars , but I've not so much as changed the oil on a bike myself.


I've a '98 ZX-6R which is having a hard time staying running over when the engines cold.


If we're starting from stone cold, I'll give it 3/4 to full choke and hit the button, and it'll come alive.

If its warm out, I'll maybe give a 1/4 choke, or sometimes none and it'll start first time.


But then the problem occurs..


Initially, the revs will hold, but after a few seconds (varies from 2 seconds, to about 30-40, tho this seems to have no relation to engine temp or environment - seems random :/) it'll dwindle right down to around 400rpm before finally dieing completely.


I'll hit the starter button and it'll be straight back alive... and the process repeats.


Now.. To get it actually started, what I have to do is give it oh such a little bit of throttle and hold it there until we get around 2 bars of "heat" registered on the clock.

Then she'll happily stay ticking over till the cows come home.


Whats odd is that if I'm not using any choke to begin with, if I add choke instead of twisting the throttle, it just dies.


Another thing to note is that if I've been out on it for a good ride (say, an hour to matlock or so). I can then leave it for a good three hours and when I start it back up, it just goes.. even if the engine is stonecold.


Finally, there is a distinct pong of fuel from the exhaust when starting from cold.. and then for a good while after too.



Would you say I've just got myself a classic overfueling issue here? Or could I be looking at something more sinister (dodgy piston rings for example?)


If it IS the overfueling issue... what would be the best solution?

A full service from a pro or just new plugs?


:?

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didn't quite understand this bit SK


"Whats odd is that if I'm not using any choke to begin with, if I add choke instead of twisting the throttle, it just dies. "


if choke is applied at tickover then bike may stop--too much fuel. But are you getting a bit 'choke' obsessed ??


in the warmer temperatures now a lot of bikes don't need choke to start--my old bike varies a lot -- if been stood for days it will start with no choke if warm day.


a carb service may be needed

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when was the carbs last balanced ?


has it been stood for a long time ?

 

Not a clue, bought it at the end of last year and I can't tell from all the service history what exactly has been done...


No.. it was a weekend bike for the last owner, and the longest I've left it standing for would be two weeks (very rare tho).

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didn't quite understand this bit SK


"Whats odd is that if I'm not using any choke to begin with, if I add choke instead of twisting the throttle, it just dies. "


if choke is applied at tickover then bike may stop--too much fuel. But are you getting a bit 'choke' obsessed ??


in the warmer temperatures now a lot of bikes don't need choke to start--my old bike varies a lot -- if been stood for days it will start with no choke if warm day.


a carb service may be needed

 

Perhaps :) I'm adding the choke from experience with a previous bike.

I'd try and start with no choke or throttle, and it'd just about manage to turn over a few times before dieing (when cold). To start it, I'd add a bit of choke and it'd start right up.

OR, if I add a bit of throttle, it'd start up without the choke.


So, with my current bike.. noticing that it wouldn't stay ticking over without throttle, I add a bit of choke to replace me having to turn the throttle a bit... (but it doesn't work :P)



What would you say is an "average" price for a carb service? (under £50? Over £200? general area would be good enough :P)


thanks for the advice so far btw :)

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so when was the last service done in the book ( milage ) and what is the milage now ?


has it always done it or just started randomly :?

 

Cant remember off hand.. I'll check tonight (but I'll be suprised if its more than 6 months)


Its pretty much always done it. I didn't notice it when testing the bike at time of purchase, but I do remember first noticing it a few days later...


Its not got any worse tho.. if that makes any difference :)

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i would get the carbs services and balanced up and check all fuel lines too


what does it idle like when warmed up ? is it nice and smooth or do the revs fluctuate slightly ?

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i would get the carbs services and balanced up and check all fuel lines too


what does it idle like when warmed up ? is it nice and smooth or do the revs fluctuate slightly ?

 

very slight fluctuation.

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i would get the carbs services and balanced up and check all fuel lines too


what does it idle like when warmed up ? is it nice and smooth or do the revs fluctuate slightly ?

 

very slight fluctuation.

 

carbs need balancing up then :thumb:


pop round and i will do them :lol:

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i would get the carbs services and balanced up and check all fuel lines too


what does it idle like when warmed up ? is it nice and smooth or do the revs fluctuate slightly ?

 

very slight fluctuation.

 

carbs need balancing up then :thumb:


pop round and i will do them :lol:

 

don't tempt me.. your not that far away :P

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so.. next question.... best shops in Notts anyone?

 

this should help :wink:


http://www.mccoys.enta.net/images/features/guide7cover.jpg

 

that's surely a man in disguise!

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so.. next question.... best shops in Notts anyone?

 

this should help :wink:


http://www.mccoys.enta.net/images/features/guide7cover.jpg

 

that's surely a man in disguise!

she has a face you would put against a brick and throw a wall at it :shock:

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