Carb Float

[dunkins1]

Ok gentlemen, I'm back for more assistance. After trying every non-invasion thing I could to get my one carb from leaking, I had to tear it down. I pulled the float bowl cover off and the float looked good and moved (by hand easily) and seemed to engaged the needle well. I took the float out and the needle. Needle is brand new and looks it. I don't see any nicks or tears in the rubber.

 

Soo.... what test or experiment can I do to test the bouancy of the float. I have two others left over from the rebuild that I could swap.

 

Also..... does anyone know if there are different float needle sizes between the V-max and Venture. A V-max guy rebuilt my carbs. I'm not sure if there are but I suppose if the rubber tip was slighter smaller that could cause it to not seat properly.

 

From a probably standpoint, what are the odds that the seat is bad? (I've posted a few other times with the leaking carb (from overflow).

 

I'm pretty convinced that it's not debris. I've drained all the bowls several times, taking the fuel line off and turned the bike on and off so gas pumped into a glass jar. Gas in all circumstances looked clear.

 

 

Thanks as always.

 

Bill

[Snaggletooth]

Hi ya Bill,

 

Now you're talking stuff I've been through.

 

OK, best way to check floats is weigh the danged things. I'm not kidding. I had problems with a couple of floats absorbing gas and sinking....causing the carb to guess what.............over flow.

 

Got my hands on a scale that weighed in grams and checked them. Yup. Soaked one was heavier. D'oh!

 

Look for soft spots on the float. I mean press your fingernail right into it soft. If it gives easy it may be breaking down. Check closely around where the brass tang attaches to the float body for coming loose.

 

Ok...simple solution. Find the bad float. Hang it in the sun and let it dry for a few days. Then a single light coat of airplane dope to reseal it. Not very thick as too much will make the float heavier and harder to adjust to the proper fuel bowl level.

 

Or...order a new float from an '85 V-Max. Same thing as the 1st gen carbs, Perfect match. I got the part number somewhere off mine. I think I paid like $28.00 per float on mine.

 

As far as the needles....can't answer that one.

 

Odds of the seat being bad......next to none. Unless somebody went to digging in there with a drill bit or pick. Not likey. Even guys that rebuild carbs for a living usually only replace the needle. And Yammy only sells them as sets. Like $37.00 per set if I remember what I paid for mine. Now replacing the seat it a neat trick to learn. Then you would understand why they like to only replace the needle. More info on that if you want it later.

 

Later

 

Mike

[bkuhr]

As for testing needle I would first have you notice that there is a little spring loaded plunger in base of needle.

 

1.Make sure plunger workes freely

2. Place piece of tubing on fuel inlet port such as you can blow light air pressure into tubing

3. Place needle in port, and while blowing you should feel air cutoff as you press on bottom of plunger against spring loaded base. Should stop airflow just as plungers just starts to compress.

 

4. If this all works, place float on pin, and repeat air pressure test. Float should be apx level (square in fuel bowl) when airflow stops, and have more room to move up against spring loaded plunger

 

As for testing float, pull float pivot pin out of carb, place on float as normal and hold between fingers as you lower float into jar of fuel. With pin apx 1/2 in above fuel, float should be level, with fuel level about 1/2 way up float. If one end or the other sinks, float is bad

 

If all ok, assemble 1 carb at a time, with needle and float. Place carb on LEVEL fuel safe table, place CLEAR (FISH TANK AIR LINE TYPE) tubing on carb drain port at bottom of carb. Secure clear tubing up along diapram cover side of carb. Rig a little bit of gravity fed fuel into fuel line at fuel inlet, and let in enough fuel to fill float bowl. While keeping fuel applied to inlet, Open fuel drain screw at bottom. this will allow fuel to fill the clear tubing to the level of fuel in the float bowl. mark this level on your diaphram covers. Pic of my level marked with pinstrip tape. Should be about level of choke shaft. If very far off will need to take carb back apart and adjust tab on the float.

 

After all 4 carbs float levels ok, assemble the rack of 4 and apply gravity fuel to main fuel inlet of all 4 and check float levels again. If all ok now, place carb into bike, hooking up just fuel line from fuel pump. Level bike and check float levels again. Here i preinstalled my black rubber drain hoses and used a little piece of brass tube to connect rubber drain hose to the clear tubing. Turn on fuel pump and check float levels 1 last time.

 

Sure others will chime in

[MiCarl]

As for testing needle I would first have you notice that there is a little spring loaded plunger in base of needle.

 

1.Make sure plunger workes freely

2. Place piece of tubing on fuel inlet port such as you can blow light air pressure into tubing

3. Place needle in port, and while blowing you should feel air cutoff as you press on bottom of plunger against spring loaded base. Should stop airflow just as plungers just starts to compress.

 

4. If this all works, place float on pin, and repeat air pressure test. Float should be apx level (square in fuel bowl) when airflow stops, and have more room to move up against spring loaded plunger

 

As for testing float, pull float pivot pin out of carb, place on float as normal and hold between fingers as you lower float into jar of fuel. With pin apx 1/2 in above fuel, float should be level, with fuel level about 1/2 way up float. If one end or the other sinks, float is bad

 

If all ok, assemble 1 carb at a time, with needle and float. Place carb on LEVEL fuel safe table, place CLEAR (FISH TANK AIR LINE TYPE) tubing on carb drain port at bottom of carb. Secure clear tubing up along diapram cover side of carb. Rig a little bit of gravity fed fuel into fuel line at fuel inlet, and let in enough fuel to fill float bowl. While keeping fuel applied to inlet, Open fuel drain screw at bottom. this will allow fuel to fill the clear tubing to the level of fuel in the float bowl. mark this level on your diaphram covers. Pic of my level marked with pinstrip tape. Should be about level of choke shaft. If very far off will need to take carb back apart and adjust tab on the float.

 

After all 4 carbs float levels ok, assemble the rack of 4 and apply gravity fuel to main fuel inlet of all 4 and check float levels again. If all ok now, place carb into bike, hooking up just fuel line from fuel pump. Level bike and check float levels again. Here i preinstalled my black rubber drain hoses and used a little piece of brass tube to connect rubber drain hose to the clear tubing. Turn on fuel pump and check float levels 1 last time.

 

Sure others will chime in

 

A little soapy water on the needle and seat will help detect leaks when you blow into it.

[Grisolm1]

I used a Vmax carb rebuild kit on mine from K&L.

 

Had to adjust all the floats as the needle was a different length and made the level far too low.

[dunkins1]

I used a Vmax carb rebuild kit on mine from K&L.

 

Had to adjust all the floats as the needle was a different length and made the level far too low.

 

 

Ahh, that is interesting. That might explain a few things. Do you know the flow height adjustment? I've read that it is 1-7/8". It sounds like maybe that could be the culprit to my overflow leak.

[Grisolm1]

Vmax needles must be slightly longer than stock. At the geometry around this part of the carb it doesn't take much.

 

Float adjustment is done using clear hose and checking level against centerline of carb body. The manual outlines this fairly clearly. Make sure you know which hose goes to which carb, they may be crossed left to right. The level is somewhere around 15-16 mm below centerline if I remember right.

 

Your problem (too much) seems opposite of having Vmax needles (too little).

[mrich12000]

Here ya go full kit ,jets and needle s for you on Eflee..

 

 

http://cgi.ebay.ca/ws/eBayISAPI.dll?ViewItem&item=330386372627&ssPageName=STRK:MEWAX:IT

[dunkins1]

Ok all, I think all your great input may have paid off. After doing many of the things above, I ended up adjusting the float tab just a sliver up. I double checked what I call the needle sleeve, it was clean and clear. Tested the needed in there and was able to get a good seal.

 

Anyway, after reassembling and starting the bike several times, I let it run for quite a while. Did this a couple of times and no overflow!!!!! Damn that makes me happy. I've been fight that for 3 months. Still have to put the bike back together, have the carbs synced again and put all the plastic back on but at least I can see light!

 

Thanks again to everyone! I'll keep my fingers crossed that this is it.

 

[jasonm.]

Vmax needles must be slightly longer than stock. At the geometry around this part of the carb it doesn't take much.

 

Float adjustment is done using clear hose and checking level against centerline of carb body. The manual outlines this fairly clearly. Make sure you know which hose goes to which carb, they may be crossed left to right. The level is somewhere around 15-16 mm below centerline if I remember right.

 

Your problem (too much) seems opposite of having Vmax needles (too little).

 

VMAX needles are the same as ours guys. At least the OEM ones are. The float height MUST be done with the carb PERFECTLY LEVEL. Using a level on the top and checking at 2 angles minimum. AND all this should be done in a vise. So you can truly check the fuel height. mark with a scribe the 16mm mark described by others. But on the side of the carb. below the centerline. Which is also on the side. Do NOT use the ceneterline marked on the float bowls. Here's another tidbit. Use at least 3' of clear hose on the drain to check the height. WHY? Because You need to simulate fuel being used. Have most of the hose above the carbs when you start. Then slowly or quickly bring it below the carb. The final fuel level should not vary. I learned this last part the hard way. Checking it once with a short hose is not enough . Also Virago 535s and 1200 Vmaxs use the same floats. As for changing a seat on one of these carbs. Anyone who can do it properly ...is a better man than me.