Stock jet size? How much bigger?

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Stock jet size? How much bigger?

Postby Swordsman » Fri Mar 02, 2012 10:25 am

Having discovered my bike is running lean, I need to get some bigger mains. I supposedly have whatever the stock jets for 2010 were, but I haven't had a chance to crack it open yet. If possible, I'd like to go ahead and pick up some bigger jets today so I can have everything ready. Can someone tell me what the stock jets should be, and what would be a good size to bump up to? I see a lot of 130's and 140's mentioned... I have 3 needle shims though, and I don't know how that would affect my needs.

Thanks!

(FYI, I did several forum searches, and never found any numbers for stock jets)

~SM
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Re: Stock jet size? How much bigger?

Postby Brian Crean » Fri Mar 02, 2012 12:11 pm

My cat-burgler kit consists 0f a 45 Pilot jet, & 130 Main jet, I also run modtops, and have 2 M-3 needle shims (Washers). Usually, most use from 125-135 Mains, and 42-45 idle, depending on local (Altitude) type of riding, ect. Installation is easy, but if in doubt check out Billy G's site, Myural.com
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Re: Stock jet size? How much bigger?

Postby Lokiboy » Fri Mar 02, 2012 12:56 pm

Swordsman wrote:Having discovered my bike is running lean, I need to get some bigger mains. I supposedly have whatever the stock jets for 2010 were, but I haven't had a chance to crack it open yet. If possible, I'd like to go ahead and pick up some bigger jets today so I can have everything ready. Can someone tell me what the stock jets should be, and what would be a good size to bump up to? I see a lot of 130's and 140's mentioned... I have 3 needle shims though, and I don't know how that would affect my needs.

Thanks!

(FYI, I did several forum searches, and never found any numbers for stock jets)

~SM


SM,

Sorry I can’t answer your jet size question. It is posted, however – Yep, finding it can be a bear. Might be a good thing to post in the FAQ section just started.

If running lean is your issue, may I suggest adjust the fuel mixture screw (under the carb - nearest the engine) before you rejet. It might accomplish the same thing. Also be aware, the jets folks commonly put in work only or idle and for to top 1/3 of throttle control. From idle to 2/3 throttle is via the jet needle. There are several good sites discussing jetting.

Motorcycle Carburetor Theory 101 http://hondanighthawks.net/carb14.htm
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Re: Stock jet size? How much bigger?

Postby Msblu79 » Fri Mar 02, 2012 1:29 pm

If you are running the stock airbox & mufflers then a #42 or #45 pilot jet will work, 130 main jet, stock needle jet with at least 2/3 shims under it or if you really want to wake it up get a set of Gossie needles and feel the power, :lol: They work alot better than stock. Turn the pilot fuel screw out to 2 to 2.5 turns CCW from lightly seated. Drill the vacuum hole in the slides out to 7/64's dia. to get a quicker response from it. Fuel milage will suffer a bit but the tradeoff is a much better running rig that makes a bit more lowend torque and HP to help the tall 1st gear off-road and on hills. If you haven't already ditch the vacuum petcock for a manual one, that can cause lean conditions especially at higher speeds or low vac situations. That should get you started in the ballpark and you can fine tune from there. :)
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Re: Stock jet size? How much bigger?

Postby Coluralado » Fri Mar 02, 2012 2:29 pm

I'll second (or third) the motion on 42 pilots and 130 mains with 2 (or 3) shims under the needle.

I don't know if you can ever actually know what the stock jets are until you pull them out. Lots of variances over the years and even within same year models.
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Re: Stock jet size? How much bigger?

Postby Swordsman » Thu Mar 08, 2012 11:05 am

Well, obviously I didn't get around to picking up the jets yet. A few more quick questions:

1.) Is there any reason why I would have to pull the carb off to re-jet? Can't I just slide up under the bike, pull the bowl off, and do it that way? Yanking the carb may be more "comfortable", but the previous owner sealed it on with some kind of rubbery glue stuff, and I don't want to break the seal (and clean up all that mess!) if I don't have to.

2.) Can jets be bought at Auto Zone and the like, or is this a dealer-only item? Don't get me wrong, I wanna support our dealers, but I don't have any locally, and I get tired of blowing $$$ on shipping.

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Re: Stock jet size? How much bigger?

Postby deeve » Thu Mar 08, 2012 11:08 am

Just lay down, drain the gas out of them, then take the bowls off. You might want to swap out the phillips heads screws for some allen head ones while your down there to make this easier. Getting at the jets with the carbs on is very easy. I bought my jets at the local Kawi/Honda/Yama shop. Just bring in what you want to make sure it matches up and away you go!

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Re: Stock jet size? How much bigger?

Postby Coluralado » Thu Mar 08, 2012 11:24 am

What Deeve said. You have to get the jets at a bike dealer/shop....Harley, Kawisaki, etc.
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Re: Stock jet size? How much bigger?

Postby windmill » Thu Mar 08, 2012 12:50 pm

It was recommended to me by those who know, :deal:

With the stock exhaust and air box, 42 idle, 126-128 main, 3 shims on the needle.
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Re: Stock jet size? How much bigger?

Postby Navy Chief » Thu Mar 08, 2012 2:36 pm

windmill wrote:It was recommended to me by those who know, :deal:

With the stock exhaust and air box, 42 idle, 126-128 main, 3 shims on the needle.


I am running this combo (42 idle, 127.5 main) with 2 shims and I am very happy with the performance. Only modifications are my cats disappeared while I was working on the exhaust one day (really weird) and a K&N filter...

:cheers:
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