Hey guys, heres the issue. I've read the service manual, read every thread, sticky, and answers on here. I tried setting the levels with the dry measurements of 1.115 and 1.125 with the carbs upside down on level surface but the wet readings were showing too lean. I was getting low wet readings with the carbs in the bike so I did measurements on the bench with auxillary tank and the readings were better but still not close to 16mm . I ended up setting the floats to 1.042 and the wet reading was closer but is still not there, on the bench it shows about 12 lines from the bottom of the index line on the glass tube, on the bike it's showing under the glass tube. The measurement and the float bowl look rich to me , but wet measurement is showing lean still. I am using the factory yamaha float gauge, with the carbs level, opening the drain screw and getting rid of air bubbles, I set the top of the index line next to the line on the carb vertically but I always get incorrect wet measurements compared to dry. Any suggestions of what I can be doing wrong?
Help Support VMAX Forum:
Are you continually cycling key on/off? Perhaps fuel pump is stopping before float bowls are full.
Rhoy Carter
Well-Known Member
I go by this when setting my float levels and have not had a problem.
See the shape of the float and that casting mark circle on the jet block? When the float height is set correctly, the edge of the float will be exactly the same as the casting mark, like the edge of a circle on the edge of another circle.
See the shape of the float and that casting mark circle on the jet block? When the float height is set correctly, the edge of the float will be exactly the same as the casting mark, like the edge of a circle on the edge of another circle.
Good advice, thanks. I cycled the fuel pump and the wet measurement finally matched up on the bike to my bench test. I still need to richen it up some more to reach 16mm , any idea why I am having to go so rich at measurement of 1.042 and about to go lower to reach wet specs.?
The casting circle is ok for general ball park but the position of that circle varies from jet block to jet block. When I measure I go from flat spot farthest away from jet block. Perhaps you're measuring with the caliper too close to the block.
When you do the bench setting with an aux. tank is the tank elevated enough (or some method of introducing a little air pressure into the aux.) to duplicate the 4# of fuel pressure the fuel pump exerts?
Also, the needle seats on your carbs may protrude into the float chamber more or less than other carbs, changing your dry level settings. The wet levels are what's important, don't worry about the dry measurements.
Also, the needle seats on your carbs may protrude into the float chamber more or less than other carbs, changing your dry level settings. The wet levels are what's important, don't worry about the dry measurements.
tugla
Well-Known Member
danny beat me too it, its not BRC for nothing. dan you might hav to send a pic of your bong so he gets what your drawing.... or is that top secrete lol.
i just hung a container up high in the garage and had the spout facing down to make head pressure.
i just hung a container up high in the garage and had the spout facing down to make head pressure.
I was doing the wet measurements last night but just to get enough fuel in the tube to reach close to 17mm under the line on the carb I had to really bend the float tang in, it's showing real rich in the carb, I am only at 20mm from the line on wet measurement and I can't bend the float tang down anymore, its showing the same on the bike. I can't figure out if I am doing wet measurement wrong or if there is a step I am missing...really stumped here.
Yeah, I just hung my aux. Tank up too, the carbs are getting plenty of fuel because my
wet bench test and wet test on the bike yield the same results. Just can't figure out why I can't get a wet reading of 16-17mm below line. I've heard of some people testing it by fuid oz. measurement, anyone know what the fluid oz. measurement would be to get 17mm under the line?
wet bench test and wet test on the bike yield the same results. Just can't figure out why I can't get a wet reading of 16-17mm below line. I've heard of some people testing it by fuid oz. measurement, anyone know what the fluid oz. measurement would be to get 17mm under the line?
Are all the carbs reading roughly the same, 20mm ? below the line?
You do have the float tangs under the little wires on the needle valves....right?
You do have the float tangs under the little wires on the needle valves....right?
E'thing's top secret at BRC Rov....you know that!! Highest clearance only!! :rofl_200::rofl_200::rofl_200:
Just to get the fuel 17 mm from the line on the side of the carb, I am having to measure precisely 17 mm from the bottom of the carb to the end of the float with the carb upside down . Makes no sense, the float won't even bend that rich. I have them set at 1.115 dry which is showing 11mm under the line on wet measurement. How in the world are you guys measuring in the 1.115-1.125 range and getting 17mm wet readings? I can't get these darn things in spec, is it possible someone would have changed the float or float needle? It just seems like the wet readings are always showing lean, and I can't get them rich enough to reach spec.
naughtyG
Well-Known Member
I must say, when I rebuilt my carbs, I checked the floats on the bench according to instructions found here, and when I later checked them wet they were very close to the mark.
Is it at all possible you may have inverted a part somewhere, which would explain why you're so out of spec?
Is it at all possible you may have inverted a part somewhere, which would explain why you're so out of spec?
I checked every internal part of the carbs to make sure nothing was out of place. I had put the carbs back on the bike and its been running decent, but seems its running still lean. A little popping and stutter in low speed, so I figured its because I still don't have the float level 100% on. When you measure with calipers, do you measure inside from bottom of bowl to float, or bottom of carb to float?
tugla
Well-Known Member
can you send a pic of your wet bench set up and where you are measuring, maybe we are all missing something in translation cause should not be this hard to get the numbers you want
sdt354
Well-Known Member
I can't say I ever got it perfect on the first or second try. I get close, but being anal,I always tweek it as close to perfect as possible. I've had my carbs off a few times to adjust the tang a tiny bit. To me it's worth it. Lots of good threads here. I'm still a student of Vmax. :snow:
Steve-o
Steve-o
95spfldmax
Well-Known Member
unk:
Does anybody have some carbs apart and can check the distance the needle valve seat protrudes into the float chamber for dhc to compare his to?
In fact it would be a good idea to get more info on this situation....pics would be great as Rov suggested....but, what else has been done to the carbs? Were you just setting float levels or is this part of a rebuild, needle & seat replacement.....? :confused2:
In fact it would be a good idea to get more info on this situation....pics would be great as Rov suggested....but, what else has been done to the carbs? Were you just setting float levels or is this part of a rebuild, needle & seat replacement.....? :confused2:
