Frustrated with cv carbs

[jby1999]

After tear down and cleaning reassemble and got to adjust floats forgot to check them my bad!
Round two I set floats using caliper method on bench upside down on bench all set to 1.117 as pictured in rebuild guides reassemble on bike do a wet check and everything was off wtf
Cyl/mm wet
1/16
2/15
3/23
4/18
Ok tear down again notice needle pins are different lengths scratching head I hit it again very frustrated but give it my best. This time I set them from top of jet block center of cast circle 17mm down to touching each float as described as a different method of measuring them yay all reset and reassembled take a break slept came out this morning put bike together and ran crisp for first I've minutes. New plugs ngk dpr8ea-9
Took a couple bearer rides to set the a/f screws and foud something very interesting only screw that starved engin was cyl 2 kept going ended up with 3.25 turns out. Starts running like poo again once it's warmed up go figure come back check plugs cyl/condition
1/black dry soot metal tang clean in spots
2/white clean seems lean
3/ same as 1 a Lil cleaner
4/ same as 3
So I do a wet check on bike even though the wet check on bench all showed 17mm with a funnel hanging 24" above carbs
Cyl/mm wet
1/15
2/13
3/17
4/17
Seriously wtf never had so many problems with these carbs. Ever since I got this bike had problems bike came from rmsportmax originally but precious owner out a jet kit in which one I don't know and has adjustable needles
Anything above 3k runs awesome has super trap sloping with race caps on it and nology hot wires every wire has spark

Besides buying all new everything for carbs what are my options on a tight budget with it just paid ins and reg and I've never had problems rebuilding snowmobile engins and other motorcycle carbs

Will not carbs havnt been synced yet as I'm waiting for my carb stick to return to me looks like ill be forced to by another one. Need opinion on which one to buy as I see you can't get mercury ones anymore
Hmu ill be checking back

 

[SpecOps13]

Wow Bro. These carbs have given me a RPITA too. I stopped using Ethanol. Don't know what you can get where you are. Once set and maintained by cleaners in the fuel, not letting the bike set and semi frequent Sync all stays well until a bit of crap gets to the float bowl. Draining the float bowls to get the trash out occasionally helps too. Sure wish Yamaha would have gone fuel injection a long time ago but WTF. We live with the occasional troubles to ride a legend that still instills fear in those who only dream of riding one.


CARBTUNE is the only way to go IMHO. To get a simple, perfect sync.

 

[jby1999]

Yeah only 87 no ethanol or 100 unleaded no ethanol 87 is 5.45 and 100 in 10.99 a gallon sooner sell the pay those prices. Why can't the USA goto straight alcohol it can be made rather cheap and everything will run on it a lot better then e15

 

[jby1999]

So I ordered new gaskets and orings new rubber caps and new air box boots from u motors. Great place. Also picked up two new idle coast diaphragms notice two had holes. And ordered up a carbtune pro with case,crossing my fingers that this will work! Upon tearing it all down today with a clear mind I'm definitely stoked about setting this up hopefully without problems this time around.

 

[one2dmax]

Had one carb that I think the float pin support was just a tad long. I think it was flexing when i'd put the cover on and always read off (and different each time).

 

[jby1999]

Could you please explain that a Lil better mr Morley

 

[jby1999]

So far my 2 coast enriched diaphragms came waiting for rest of gaskets orings and carbetune "can I get a hot tub" while I wait?

 

[sdt354]

After tear down and cleaning reassemble and got to adjust floats forgot to check them my bad!
Round two I set floats using caliper method on bench upside down on bench all set to 1.117 as pictured in rebuild guides reassemble on bike do a wet check and everything was off wtf
Cyl/mm wet
1/16
2/15
3/23
4/18
Ok tear down again notice needle pins are different lengths scratching head I hit it again very frustrated but give it my best. This time I set them from top of jet block center of cast circle 17mm down to touching each float as described as a different method of measuring them yay all reset and reassembled take a break slept came out this morning put bike together and ran crisp for first I've minutes. New plugs ngk dpr8ea-9
Took a couple bearer rides to set the a/f screws and foud something very interesting only screw that starved engin was cyl 2 kept going ended up with 3.25 turns out. Starts running like poo again once it's warmed up go figure come back check plugs cyl/condition
1/black dry soot metal tang clean in spots
2/white clean seems lean
3/ same as 1 a Lil cleaner
4/ same as 3
So I do a wet check on bike even though the wet check on bench all showed 17mm with a funnel hanging 24" above carbs
Cyl/mm wet
1/15
2/13
3/17
4/17
Seriously wtf never had so many problems with these carbs. Ever since I got this bike had problems bike came from rmsportmax originally but precious owner out a jet kit in which one I don't know and has adjustable needles
Anything above 3k runs awesome has super trap sloping with race caps on it and nology hot wires every wire has spark

Besides buying all new everything for carbs what are my options on a tight budget with it just paid ins and reg and I've never had problems rebuilding snowmobile engins and other motorcycle carbs

Will not carbs havnt been synced yet as I'm waiting for my carb stick to return to me looks like ill be forced to by another one. Need opinion on which one to buy as I see you can't get mercury ones anymore
Hmu ill be checking back

The best way to get floats very close is to set carbs in two's on a level surface with the carb boots attached. Fill with fuel, make sure the test hoses are air bubble free. and check the levels. It's easy to just take the bowl cover off and adjust the tang. In a recent rebuild I found the needle seat protrusion on one carb to be longer than the other three. This would make the caliper measuring ineffective. A final check on the bike is required. You can still mount the carbs in two's on the manifolds in case adjustment is needed. This is the fastest way for me, instead of fully assembling carbs and linage every time. I take as much time as I need to get all four dead on 16.5mm. It's worth it.
Morgan carb tune is my favorite. If you have a vmax, a sync tool of any type is a necessity.

 

[jby1999]

Carbtune arrived still waiting or parts should see them tomorrow. Quick question when syncing the vmax do I do it with the air box on?

 

[Traumahawk]

Carbtune arrived still waiting or parts should see them tomorrow. Quick question when syncing the vmax do I do it with the air box on?

Yes you do it with the airbox on.

 

[jby1999]

Alright parts showed up today thank you u motors great prices. Spent my evening tuning a 74 cr250 the guy had no clue and his normal engin guy he and him had a falling out. Was told it runs better then it ever did so now I have faith this will work. My guess was the guy never set it up right because he wanted to win the same vintage race.

 

[jby1999]

Very confused at my float heights carbs upside down resting farthest right point of float to inside of bowl measures 1.161" and I'm still gettin a 15mm wet reading everything is level wtf everyone else is sing 1.125 for 17mm

 

[jby1999]

According to math to drop the fuel level 2 mm I need my float height to be 1.241" wtf

 

[jby1999]

Carb on left is upside down #3 finally get a wet measure of 17 carb on right is #4 has 12mm wet why so far off from measurements posted carb 3 measure 1.335" carb 4 measures 1.058

 

[jby1999]

Just did again had another pair of eyes looking at setup picture and we adjusted carb 4 made the measurement exactly 1.117" as in the picture and have a 13mm wet please someone chime in

 

[tugla]

How r you checking the wet level????

 

[jby1999]

I have a piece of 1/8" fuel line connected to the drain hose with a 90 barn fitting have two zip ties on hose to mark 15mm & 17mm from the top which I align at horizontal mark on carb body. Carbs and fuel cold bike hasn't been started trying to iron it out before I fire it up.

 

[tugla]

And the supply of fuel,make sure u have more then owls hold and ifu have it higher then carbs will give good head pressure to system,so I assume u just doing it on bench to on the bike...

 

[jby1999]

I believe that the wet measurement is far more important then the bench but has anyone else had such far off measurements both carbs in that picture will need to be set that far out to achieve the wet measurement that is if my measurement tool is what it is supposed to be (4"x1/8"I.d fuel hose have a wire Ziptied to it to keep it straight have a 1/8" vaccume/fuel 90? barb fitting to connect to the drain line!
My process is to attach hose after cycling fuel pump open drain line let fuel run to remove air and cycle pump once more I get a half click I raise hose top top of carb and then lower to line and watch level rise in hose. Bottom of the rounded fuel level will measure 12mm when bike is leveled front to back and side to side on Motojack. Have only got carb number 1 to use bench measurement to correspond with wet carbs are together in two banks 1/2&3/4 so I can easily remove to make adjustment. As I had problems before I learned from a Lil reading. If I set them with a funnel going Into fuel line in bench it's close but on bike it's way off.

I am beyond frustrated and don't understand why this is being such a pain. When I'm measuring dry I set my veneer to 1.125 and place on far right side level with inside fuel bowl and measure up to float corner. All the while carbs at upside down with gravity pressure on needle the tang is engaged but not depressing the nipple of float needle. Tang is inside catch spring correctly. Can someone please tell me what I am doing wrong.
I would imagine the needle / seats are stock no way to tell but there is no wear ring or damage to needle or seat observing with bright light and a magnifying glass!
I'm gonna try to sort out tomorrow hopefully someone can post something that helps.
I don't object to setting them according to bench and fully assembling carbs to fire it up but being that my bench measurement is off by .214" to achieve my wet number I want to verify that the bench measure goes out the window for these.

 

[jby1999]

All said and done she runs better then ever now. But still need some tuning had one pop out the top riding and if idles too long it seems to load up a Lil nothing major. But I am thinking of ditching the 155's for either 152.5 or 150 need to have my jet kit returned to me so I can do that!