How often do you clean carbs and sync them?

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darthzuasive
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How often do you clean carbs and sync them?

Post by darthzuasive »

Hey everyone, I realize this might be a bit of an over generalized question but I wanted to get a idea.

My yzf1000r has recently started to crackle a bit at deceleration and started taking an extra push of the starter to get her going (3/4 choke). I have looked into the airbox and found that it has a k&n filter but it doesn't really look dirty. My question, how often do you clean and sync your carbs. Also, the exup (which I haven't serviced yet).

Thanks, or cheers rather. I could use a beer, pint, litre, heck how about a pitcher?
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darthzuasive
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One part resolved

Post by darthzuasive »

Well it appears that I resolved one part and that was the rough start. I just gave it 1/4 choke and she started right up. Is it me or do many engines seem different on their level of choke usage for a cold startup?

I should add the caveat of my background here. I may ask stupid questions as this is only my second street bike. I am a computer engineer/support guy so technology is my common practice. My father was a mechanic and I spent a great deal of time learning from him so I thankfully have mechanical ability. That being said, some of the things that may be common sense to the bulk of you more experienced ones will be missing from my arsenal. The main thing here though is that I love to learn, always have and I'm quick on the uptake and have mechanical intuition.
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Post by Fatdog »

A cold engine should start on most choke settings, you generally then adjust it to get a smooth idle (I go for about 2k).
Summer / winter times will have an effect but only in the length of time you run the engine with choke.
If you don't know the service history of the carbs then I would clean and balance them for piece of mind (and it won't do any harm!).
I generally clean them once a year at winter time when the bike's off the road.
Once you have balanced the carbs they should be good for a few years (provided you don't do any work on them that involves taking them apart).
It's not a big job to do, but make sure your valve clearances are in spec first as they will affect the vacuum readings
If it stills runs rough after a clean / balance, then you might want to start looking at replacing jets / needles.
Hope that is of some use. :)
1993 YZF750R
EXUP - Knee Down
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darthzuasive
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Thanks

Post by darthzuasive »

Thanks Fatdog, thats exactly what I was looking for. I don't know the service history of the bike unfortunately. I haven't done much to the engine other than change the oil/clutch and check the air filter adjust idle (was at 1600 and the manual says 1200). Like I stated I'm still relatively a noob just and educated one. It seems the choke is more weather related, since its been warmer lately no choke was required although today it was on the second crank. It warms up in about a minute if that.

Ultjmately she's still running fine, a little lean but fine. I will plan on cleaning up the carbs this winter and am looking forward to finding out if its jetted.
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Post by MMUK »

One thing to note with the Thunderace - if you fit a K&N or other non-standard air filter you will need to adjust the fueling or it won't perform as it should. K&N filters are much higher flow than OEM items resulting in a leaner mixture. Over time running a bike too lean will burn out the valves.
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darthzuasive
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Slacking

Post by darthzuasive »

Thanks MMUK, it does have the washable K&N filter.

Alright, so I've been slacking and not doing much. I went ahead and sync'd the carbs. I'm planning on doing a cleaning this fall/winter.
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