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Keihen CV34 Sync
- Patton
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I had the petcock set to prime when I was checking the level. Is this not correct? I kind of thought it would have to be set to prime otherwise the fuel level in the carb wouldn't be able to settle to its "final" level.
I did clean out the float valve seats with a Q tip and carb cleaner when I had them apart. I may try rechecking the level by covering the hole and moving the tube like you said you do.
Engine OFF, and with the clear tube in position on dry carb and being held steady against carb, (vac petcock in ON position so no fuel is flowing), THEN turn petcock to PRI so fuel will flow into the float bowl (which also flows into the clear tube).
On CV carb, clear tube is connected to overflow nipple, and drain screw is loosened, all as part of pre-test set-up with dry carb, before lastly allowing fuel to flow into carb.
covering the hole --- :huh: What hole? Don't know of any hole that needs to be covered as part of the clear tube test.
moving the tube --- tube should be held steady and unmoved throughout the clear tube test.
Good Fortune!
1973 Z1
KZ900 LTD
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- kz750saskatoon
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"Covering the hole" was referring to JR's post. He said he puts his thumb over the open end of the clear tube if there is an air pocket to lower the tube so that the air goes back into the carb body.
1981 KZ750-H2
Saskatoon, SK
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- Patton
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I did not realize the carb should be completely dry. That may change things! I learned something today and it is only 835!
"Covering the hole" was referring to JR's post. He said he puts his thumb over the open end of the clear tube if there is an air pocket to lower the tube so that the air goes back into the carb body.
"Dry carb" refers to "empty float bowl."
With manual slide carb, filling clear tube with fuel from drain hole, will entail removing the drain screw to attach the clear tube. Removing the drain screw empties the float bowl. So the test starts with an empty float bowl.
Some CV carbs have a dual purpose nipple from bottom of float bowl. Normally, this outlet serves as an overflow when the fuel level gets way too high (one purpose). When the drain screw is partially opened, the same outlet serves as a float bowl drain (other purpose).
Performing the clear tube test on this type of CV carb entails attaching the tube to the nipple, and partially opening the drain screw to allow fuel flow into the tube.
It might work okay to clear tube test a CV carb without first draining the float bowl. Just seems more glitch-free to start with an empty float bowl and allow both the bowl and tube to fill simultaneously (and perhaps help avoid an air bubble in the tube.)
Would defer to JR's experience with CV carb clear tube testing.
Good Fortune!
1973 Z1
KZ900 LTD
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- JR
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but hopefully not until next Spring though .
I do find that if I leave the petcock on Prime the level will - after a time - rise very slowly.
1980 kz750E1, Delkevic exhaust
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- mark1122
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- Keep twisting it
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if u have the bowl full and lower the tube , the fuel will drain into the tube. then when u raise the tube into posision, the fuel level will be higher, since the float seat will close and trap this EXTRA fuel in the bowl and line. This will distort your test.
i like to put a mark on the tube, so that it is held at the carb at the same length every time. if u were to buy 1 of these tubes, it would have graduated lines right on the tube for measurement purposes. so i have made 1mm graduations on mine as well.this makes things simpler,for me.
76 KZ, frame gusset work,1200CC.Ported by Larry Cavanaugh, 1.5mm.over intakes, Carron Pipe, ZRX12 rear end, and seat,96zx9 front end.
01 CBR600F4i Track bike.
Cobourg, Ont. Can.
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- kz750saskatoon
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Held it there for a while and the level did not rise. Doesn't this indicate that the float needle is closing?
I am going to swap out the bowl. I tested it at the sink with water but maybe there is something else I am missing with that test. Lets me eliminate one more variable.
1981 KZ750-H2
Saskatoon, SK
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- kzcafe750_24
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1981 Kz 750-4 LTD - Wiseco 810 Big Bore,Ported cylinder head, GPZ 750 Cams,Dyna Ignition(DynaS,Green Coils,DRL400 2stage Revlimiter), RC 4 into 1 fitted with Yoshi muffler, ZR550 Swing arm, ZR550 Rear Rim, ZX750turbo front end SuperFlo Dyno Tuned- 68WHP&43WTq(ftlbs)
1986 Honda Rebel 250 (Stock)
1985...
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- Polar_Bus
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And next time around I'll try Patton's dry bowl method
but hopefully not until next Spring though .
I do find that if I leave the petcock on Prime the level will - after a time - rise very slowly.
This generally means you have a suspect needle/seat assembly(s). Some seat assemblies use and o-ring and are pressed into the carb body. Ocassionally the o ring dry rots and allows fuel to weep past the seat. generally no matter what carb config you have, fuel intermittantly leaking out the overflow vent is a bad needle and seat. Tipping the bike side to side and then seeing fuel leak out the overflow can signify too high a float level.
Quick and strange story from years ago, I had a consistant light leak of fuel out the vent on an old RM250 dirtbike. I replaced the needle assmebly TWICE and it kept leaking ! I was going nuts trying to figure out what was going on. Finally upon a very close inspection of the carb bowl brass vent tube I realized the brass tube inself had a thin crack below the fuel level, so the fuel was leaking past the vent tube !
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'84 GPz1100
'06 HD Fatboy
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- kz750saskatoon
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1981 KZ750-H2
Saskatoon, SK
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