Author Topic: Getting the jet needle out of the throttle valve?  (Read 27153 times)

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Offline Friar-Tuck

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Re: Getting the jet needle out of the throttle valve?
« Reply #60 on: May 10, 2010, 11:55:45 AM »
Well, unfortunately either way you have to get into the carb, which ever you prefer.

 Also yes on the suspension,  even the weight of the bike on the springs does take some toll on them.
   Even a cheapskate like me has a five gallon bucket with a small piece of wood on it to unload the suspension while not in use.
   Tuck\o/
 
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Offline mustangfury

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Re: Getting the jet needle out of the throttle valve?
« Reply #61 on: May 11, 2010, 12:24:25 AM »
ok so when i change the mid range jetting, to test that, do i ride around in the mid range for a while (1/2,1/4, or 3/4 throttle?) and then just hit the kill switch after it warms up to operating temp., then take a look at the plug?

I also noticed the slow/pilot jet targets more of the low speed than the mid range but has some effect on the mid range according to the diagram on keihins website. 

http://www.keihin-us.com/am/_media/pdf/slide_valve.pdf

Would i test the pilot jet using the bikes idle or some midrange throttle (1/4 or 1/2)?

Here are pictures of what the plug looks like from riding around at 1/4 to 3/4 throttle with the current settings: 155 main, 3rd clip position, 52 pilot.
1993 KX 125

Offline Friar-Tuck

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Re: Getting the jet needle out of the throttle valve?
« Reply #62 on: May 12, 2010, 06:28:29 PM »
 Hey Stang,
 Just got back from Work,  The Plug chop is for the main. Yes you are right about the the circuits.
Cleaning up the midrange will prevent loading up the pipe and powervalve with excess fuel and blasting it out on your bike when you run the bike up wide open.
  How is the throttle response?  how is the bike running now?  what is the spooge /oil factor now?
By the way,You have a great camera there, I can see the ring at the base of the porcelain in one pic and still hasn't gotten any color on it yet.
  The plug looks way better than the first photo's no?   The only way to verify the midrange is either with an O2 sensor or how it feels in the seat of your pants.  You should be able to tell the difference of when you first started changing the jetting and now.  When it was running rich & oily the sound of the engine is more of a "blubbery" sound.
  The engine note should be more crisp, and your throttle response should have improved.
  What you are looking to do now is get clean acceleration off Idle to wide open.
Tuck\o/ 
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Offline mustangfury

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Re: Getting the jet needle out of the throttle valve?
« Reply #63 on: May 13, 2010, 07:41:50 AM »
The camera is a canon powershot sd1400. It is awesome at macro photos and photos in general.  If you put it on a stand you can get the pictures even better than what i posted. I really like it. It's the nicest compact camera i've ever found.

The throttle response is great pretty much all throughout.  The only time it may be a little hesitant is right at the start from a stand still.  At the top end it is a beast.

At idle the muffler tip gets a little oily and begins to douse the rear fender.

The spooge/oil factor is shown in the picture of the rear fender in the previous post.

I have had finals this week at college, so I haven't had much time to mess with the bike. I will be done this monday though and my buddy and i are hoping to take a trip with our bikes sometime soon after that.  I will definitely be working on it soon after monday.
1993 KX 125

Offline Friar-Tuck

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Re: Getting the jet needle out of the throttle valve?
« Reply #64 on: May 13, 2010, 09:09:26 AM »
Stang, best of luck on the finals.
 I was hoping the spooge was tapering off.   There are needles with a larger taper, and actually with up to three different tapers.  Unfortunately the needles are around  $25.00 so you don't really want to buy a few and try to clean up the off Idle
  without making darn sure thats what you need.   
  Run a few gallons of pre-mix through the bike and let me know if your still getting the plague on the fender..
Tuck\o/
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Offline mustangfury

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Re: Getting the jet needle out of the throttle valve?
« Reply #65 on: May 13, 2010, 09:58:27 AM »
I'll definitely mess with it a bit before i get any new jets or needles. I still have a lot of options to work with. 

One other thing i just thought of.  If i tip my bike to one side, i can't remember which - i believe the left, by about 30 degrees or more from vertical, fuel will begin streaming out the overflow valve on the side of the carb.  It will run as fast as if you had the fuel line disconnected from the carb and opened up the valve.  Do you know what could be causing that?  I was thinking maybe the float height?  It might just be a little high but not high enough for fuel to flood into the engine unless at a slight tilt.  Let me know what you think.
1993 KX 125

Offline Hillclimb#42

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Re: Getting the jet needle out of the throttle valve?
« Reply #66 on: May 13, 2010, 03:40:16 PM »
That is normal. Fuel does come out when you tip it.

Offline mustangfury

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Re: Getting the jet needle out of the throttle valve?
« Reply #67 on: May 13, 2010, 11:01:36 PM »
So, if you lean your bike against a tree while you take a break your fuel tank may empty?

Do you just shut off the fuel to prevent that?
1993 KX 125

Offline mustangfury

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Re: Getting the jet needle out of the throttle valve?
« Reply #68 on: May 14, 2010, 06:41:41 AM »
ok tuck,

I did some more tests today.  I put in a 50 pilot jet and ran it at all kinds of different clip positions, starting rich of course.  The bike ran the best in the mid range when the clip was as rich as possible. Off the start was still bogging and mushy sounding.  Off the start the bike ran the best when the clip was in the middle position. It had great acceleration then as soon as it hit mid range it nose dived forward and bogged real bad. It needed more fuel. I put the choke on then it did the opposite.  Started a little slow then took off when it hit the mid range.

The plug looks a lot different.  I attached pictures.  The electrode is white on the intake side and black on the exhaust port.  I never went WOT with it.  I rode around at 1/4 to 1/2 throttle and got her nice and hot.  Also, i got her warmed up to operating temp with the old plug, then switched to the new one after she was hot.  The pics are of the new plug.

I disregarded the oil spitting because i know there is a lot that needs to be cleaned out that is left over from the last run.  It was a lot less though.  I think it may have been running a little too lean.

The bike overall performed better with the way it was before with the 52 main. the only thing that was better with the 50 was oil spitting and maybe the plug color, depending on what you think.

The weather today has been about 80 degrees and the humidity 60%.  The other days tests were in 70-75 degree weather with 30% humidity.
1993 KX 125

Offline mustangfury

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Re: Getting the jet needle out of the throttle valve?
« Reply #69 on: May 14, 2010, 06:47:23 AM »
here are more spark plug pictures.  i tried to get some to show the one side being black and the other white.

I was thinking maybe try to put the 52 pilot jet back in and then lean out the clip position. The other thing i was thinking about trying was maybe to go back to the 158 main jet and see what it does.  I am going to wait till i hear what you think about everything though.  If you think it is ok, i was thinking getting it up a little further in the throttle might tell us something too?

they all look lean to me but i don't know if that has to do with the fact i didn't go WOT at all.  I didn't want to run it too hard since it might be lean.

thanks
« Last Edit: May 14, 2010, 07:20:18 AM by mustangfury »
1993 KX 125

Offline bigbellybob

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Re: Getting the jet needle out of the throttle valve?
« Reply #70 on: May 14, 2010, 08:02:41 AM »
looks lean to me like melt the piston lean. its hard to imposable to get a reading on an old plug. it could look good as the extremely rich darkness is getting burn off but be way lean.

take a look at this before you ride it any more. it has a good plug chart at the bottom of the page.
http://www.bcchapel.org/pages/0003/pg11.htm

this is a good how to on 2t jetting
http://www.yellowdogracing.com/techstuff.htm

« Last Edit: May 14, 2010, 08:08:15 AM by bigbellybob »
IF RIDING IS OUTLAWED ONLY OUTLAWS WILL RIDE

IF RIDING IS OUTLAWED ONLY OUTLAWS WILL RIDE

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IF RIDING IS OUTLAWED ONLY OUTLAWS WILL RIDE

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Offline mustangfury

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Re: Getting the jet needle out of the throttle valve?
« Reply #71 on: May 14, 2010, 09:46:31 AM »
this is a new plug.  i only rode with it for about 15 minutes.
1993 KX 125

Offline bigbellybob

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Re: Getting the jet needle out of the throttle valve?
« Reply #72 on: May 14, 2010, 10:14:16 AM »
wite on the plug = hole in the piston.

your plug should not be wite at all.
IF RIDING IS OUTLAWED ONLY OUTLAWS WILL RIDE

IF RIDING IS OUTLAWED ONLY OUTLAWS WILL RIDE

IF RIDING IS OUTLAWED ONLY OUTLAWS WILL RIDE

IF RIDING IS OUTLAWED ONLY OUTLAWS WILL RIDE

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Offline mustangfury

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Re: Getting the jet needle out of the throttle valve?
« Reply #73 on: May 15, 2010, 06:40:56 AM »
ok i put the 52 pilot jet back in and the color of the plug is much nicer again. It is that nice mocha brown on the electrode after riding around at 1/4 -1/2 throttle, but the plug is also very wet still.  I am going to mess with the mid range clip position stuff now. I'll let you know how it goes.
1993 KX 125

Offline Friar-Tuck

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Re: Getting the jet needle out of the throttle valve?
« Reply #74 on: May 15, 2010, 10:44:31 AM »
Stang,
  The fuel you see when the bike is leaning over is fuel running out your overflow.  The overflow is the little brass tube in the bowl of your carb, so yes, it will pour out quickly as there is no restriction on it.
    The way you are describing the overflow, I would also agree your float level is too high.
The correct height will be in your manual.   This could be contributing to this,
 
Quote
The bike ran the best in the mid range when the clip was as rich as possible. Off the start was still bogging and mushy sounding.  Off the start the bike ran the best when the clip was in the middle position.

Quote
i put the 52 pilot jet back in and the color of the plug is much nicer again. It is that nice mocha brown on the electrode after riding around at 1/4 -1/2 throttle, but the plug is also very wet still. 

Riding around at 1/2 to 1/4 will tend to load up the engine & plug after a while, and that may be why you found the plug to be wet again.

 If the bike is running better with the choke on she needs more fuel.
   Tuck\o/
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