Topic: keithlin jets or aftermarket?

[mathias2803]

I have heard there is some quality difference between keithlin jets and valves and aftermarket. Also in how they perform. Should I just put back the keithlin parts? Don't know if you can see the logo on the valve, but if you can is that the keithlin logo? Looks like half a star ish. If I should put back the keits, what parts are okey to replace?
I had pods earlier and rebuilt the carbs, but now I have the oem filter and the spark plugs are turning black, idle is not good and the exhaust is black inside.

[slikwilli420]

Always use Keihin brass for any replacement parts. The brass never really wears out so no since in replacing just because. Unless you have a leaking float needle/seat, there is no since in replacing them as the Honda ones are expensive.

[mathias2803]

Always use Keihin brass for any replacement parts. The brass never really wears out so no since in replacing just because. Unless you have a leaking float needle/seat, there is no since in replacing them as the Honda ones are expensive.

I might be having leaking float since I have noticed gas in the oil. That's with the replacement part


Is this a wearing sign on the needle?

[MikeSimon]

The Keihin float valves usually are not marked. They do not have a Keihin logo.

[pjlogue]

Unless you kept the fuel needle with its respective valve seat it will most likely leak if they get mixed up.  This is because the seat and needle form a worn pair over time.  The fuel valves can be replace with aftermarket of good quality.  The jets and emulsion tubes are what is very important to keep Keihin. 

-P.

[mathias2803]

The pictures are from the old stuff that was in the carb. You are talking about the needle in the picture right? I replaced the needle and float valve from the same aftermarket kit. Think I got the rebuild kit from carpy's.

Well my jets have the Keihin star looking thing logo, the dot over the i in the logo.
These were in the carb when I bought the bike.
Does keihnin still produce the jets and valves?


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[pjlogue]

If the float valve (which consists of the needle, seat and gasket (or washer)) are from a new rebuild kit you should be OK.  If you have old fuel valves and start mixing a seat from one carb with a needle from another carb is when you get leaks. 

-P.

[mathias2803]

If the float valve (which consists of the needle, seat and gasket (or washer)) are from a new rebuild kit you should be OK.  If you have old fuel valves and start mixing a seat from one carb with a needle from another carb is when you get leaks. 

-P.

Got it thanks. Then I should be good. Maybe I have a float that is sticky since it is gas mixed in the oil. I will check the carbs tomorrow. Will change the o rings and maybe the needle, perhaps move the clip aswell since the bike runs rich

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[Bankerdanny]

I had problem after problem with the aftermarket float needles that were in my 550F (installed by the PO, not me). I finally broke down and bought 4 OEM sets (needle and seat). Before I installed them I measured with digital calipers and the aftermarket needles were shorter than the OEM.

[pjlogue]

Things to check with the floats are:  Make sure there are no barbs on the brass frame for the floats where it is next to the pivot pin holders and there are no places on the pillars where the brass frame can catch.  Also be sure the floats pivot on the pin smoothly and the pin isn't chewed up and the tang on the float lever isn't dimpled.    Floats should sit on a fat surface so both lobes are even on the flat surface.  When setting the float height it's important to have the float hanging down from the pivot pin and rotate the carb so the float just seats on the fuel valve pin.  You don't want the weight of the float compressing the spring on the fuel valve. 

Once you have the float height set this way yoou should check it with the clear tube method.

-P.

[ekpent]

  If you have gas in your oil also make sure your fuel petcock is not leaking through when shut off as a leaker won't help your cause .

[mathias2803]

I have ordered 4 new oem 2.5 seat and needle since the ones I have were aftermarket and 2.0. The pin and float height are all good.

I don't understand why everyone say check float height? How can the height suddenly change itself?

The petcock is new and has been shut off every time since I changed oil. But the gas smell is still very noticeable, especially in the exhaust. I always stank after working with the bike

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[HondaMan]

Is this a 750? (Looks like the carb parts are...).
Check your jet sizes. If Keihin, I'd suggest starting at #40 pilot jets and #105 mainjets with today's fuels. If the jets are Keyster, #40 pilot is OK, mainjet should be #107 or #110 for the same mixture. Keyster's jets seem to always run leaner than their numbers.

Also: make sure your ignition timing is correct and not advanced a lot. Too much advance causes spitback into the carbs, causing them to run richer than normal.

[mathias2803]

Is this a 750? (Looks like the carb parts are...).
Check your jet sizes. If Keihin, I'd suggest starting at #40 pilot jets and #105 mainjets with today's fuels. If the jets are Keyster, #40 pilot is OK, mainjet should be #107 or #110 for the same mixture. Keyster's jets seem to always run leaner than their numbers.

Also: make sure your ignition timing is correct and not advanced a lot. Too much advance causes spitback into the carbs, causing them to run richer than normal.

Yes you are right Hondaman, 750 k3.
Pilot is 40 and has a Keihin logo on it(Not installed now) The main is 110. Unsure of the manufacturer, but I will look into it when I'm replacing the float seat/needle. Both Pilot and main currently installed is from a kit I bought from dimecity, remember the package was white and blue.

I have set the timing once, but since it was my first time doing it I will double check!
Also I'm running a 4-1 yoshimura replica from yamiya

[mathias2803]

Timing is good using light method, light goes on exactly on the F mark. Gap in points are.012 / 0.30mm and spark gap at. 028/0.60mm. Looking at the points when running the starter the spark between the ignition points seem weak?

Spark seems to be all over the place and not between the points. This happens with denso plugs and NGK iridium
https://youtu.be/t_3wo5lj_q8