Carb tune.

[Clyde Porter IV]

Sean was kind enough to share this reference guide. I took a more clear picture can anybody feel good enough about matches to land bingo? And if so are they stock and how would I refer to if and when I ever need parts. It’s a used buy and has a couple of Mods Runs like Beast just needing to get to know her better.

 

[gentsvmax]

Looks like #4 to me.....or could it be 1, hell #3 is a close one too, or is that a 2?
Take it out of the slide for the reveal.

 

[Fire-medic]

I've posted this one before first contributed by another, I added the text.

Yours looks like a USA stock needle, with 1 groove. How many does it have?



Your pic a bit bigger.

 

[Clyde Porter IV]

Looks like #4 to me.....or could it be 1, hell #3 is a close one too, or is that a 2?
Take it out of the slide for the reveal.

Man Carbs and Carbs accessories don’t like to be disturbed lol. There is a large flat head inside said Slide. Will I be able to get its adjustment spot on easy after I disturb it?

 

[Clyde Porter IV]

Looks like #4 to me.....or could it be 1, hell #3 is a close one too, or is that a 2?
Take it out of the slide for the reveal.

Does it unscrew and if so do I need to know how many from flat bottom? Like I said this thing is ????ing incredible.

 

[PATMAX]

And to further muddy the needle discussion, it pays to be conversant in Shimming of the needles just below the circlip. In picture, 1-4 have no adjustment. The last four have four adjustment slots At the top. I’ve had a Vmax since 85 and am still “guessing” at this skill. You sneak up to optimized running but exhaust gas analyzer is THE true test of efficient combustion.
There used to be “Paul’s Shim Kits” out there. It has decent instructions along with the various shims(washers) to fine tune things. I am at near sea level myself and never outside that parameter. You high elevation folks probably benefit greatly !

 

[Fire-medic]

Some info for you. Look at this diagram, look at your parts, carefully, and reassemble it the proper way. To answer your questions, and to access these parts we are looking at #8. This assembly is comprised of multiple small parts.

A digital camera or your cellphone, if it has a good close-up function, is always a good idea for documenting order of disassembly, for your reassembly. Good, close-up pictures ensure you're doing things properly, that you document the order of disassembly, they relieve anxiety and frustration, and ensure the reassembly is correct.

FYI, I suggest working in a tray, with a terrycloth liner, to keep parts from bouncing-away as you disassemble things. The tray helps to corral the various small pieces, the terrycloth deadens any 'bounce' from dropped parts, and I recommend something white instead of dark for the terrycloth, parts show-up better. Do one assembly at a time. If you get stuck because you doubt your abilities/memory, you have the factory shop manual, and three more slides in the other carbs to use as points of reference. Take your time. Get things clean. If you have an animal that likes to jump onto your work area, put them in another room, and shut the door.

There are large trays with snap-on lids you can use to secure the disassembled parts, if you have to interrupt your work efforts. WalMart, Target, or a kitchen supplies store, or the internet will have many choices. I suggest bigger is better.

Use a large-blade slot head screwdriver which snugly-fits the white nylon screw inside the slide, to remove the screw. There is a small spring underneath that. Be careful if you turn the slide upside down to remove that white nylon screw, as the spring could run and hide somewhere. It's better to keep the slide upright, and to use a pair of needle-nose pliers to remove things one at a time. First the white nylon screw, then the spring, then the needle.

If there is gunk on the needle, or if the carbs were left stored with gasoline in the float bowls, the needle may be held in-place by the sticky gunk. A shot of carb cleaner, then grabbing the top of the needle with the needle-nose pliers, a few back & forth movements of the pliers, and that sticky needle should pop out.

VMX12- Service-Manual.pdf (vmoa.net)



It's ~ 5-1/2 turns from the white nylon needle cap inside the diaphragm slide being snug. This does not need to be torqued-down excessively! Snug is fine.



This is a slide from a dirty set of carbs, you can see crud. The needle has a flat washer, a circlip, then a couple shim washers (they are stuck-together on this picture, two-up from the bottom needle in the picture) on this needle, and a thick nylon washer with an off-center *** on it which indexes into the black plastic diaphragm slide (the small hole to one-side of the center small hole).

To disassemble things, with the needle on your work area, use needle-nose pliers to remove the E-clip/circlip beneath the first flat washer, which should easily slide off, exposing the circlip. Be careful, as these, like the spring you already removed, like to run and hide when working with them. Should you lose it, Harbor Freight Tools sells an assortment of them, inexpensively, same for that tiny O-ring below the CV diaphragm cap, which often will stay in-place on the carburetor body as you remove the diaphragm cap, to begin your work with the slide and the needle, and their multiple small parts.



External Retaining Ring Assortment, 300 Pc. (harborfreight.com)

O-Ring Assortment Pack - 397 Piece Metric O-Ring Assortment (harborfreight.com) Less than $14 for both.



Look at this picture, at 6 o'clock, you see a large hole, this allows controlled motion of the slide up and down as air passes through it. This is the hole which is bored larger in the Dynojet Stage 7 carburetor jet kit directions. Directly above it, there is another hole, this is for the needle. Above that, is a yet-smaller hole, that is for the off-center *** of the needle nylon washer to index-into.



I suggest that when removing or installing the thick nylon washer with the off-center ***, on/off the needle, that you do it from the needle's tapered end. In other words, instead of trying to remove it from the top of the needle, where it rests, slide it down towards the taper. I've found that it comes-off easier going in that direction. Also a spritz of carburetor cleaner on the stuck-together parts will help loosening gummy bonding among parts.

When you use a pair of needle-nose pliers to insert the needle stack into the center needle hole, grab the needle as it emerges from the bottom of the slide, and gently, slowly rotate it, and you will feel the *** drop-into the small hole, and the needle drops several mm more. Now the spring goes on-top of that needle stack, and the white nylon screw plug screws in to secure the assembly. Snug that screw, you can strip it if you use too-much torque.

See the encrustations on the towel? That is enough material to plug a pilot jet! Use an aerosol carb cleaner to thoroughly clean all the pieces before reassembly, including the interior of the black plastic throttle slide. Hopefully, your diaphragm isn't torn, if it is, time for a replacement. You can try the by-themselves aftermarket diaphragms, or replace the entire slide and diaphragm, which is how Yamaha sells them.

Take your time, assemble things properly, use needle-nose pliers to insert to needle stack of pieces, then the spring, then the white nylon screw cap, and don't over-tighten it.



More-experienced members than I am, who can speak to issues of carburetion on a VMax are CaptainKyle, Sean Morley, dannymax, and Damon. Reach them for a PM under the Members tool. Note that the spelling and capitalization need to be exact for the search function to work.

 

[one2dmax]

I would say #3? Original pics attached.

 

[dannymax]

Stock needle will have 5EZ43 stamped just below the 'E' clip groove
According to the diagram #3 & #4 are stock

 

[Fire-medic]

Like this. The first character before the 5 is a Mikuni mark. Left to right: (Mikuni mark), 5, EZ, 43.

 

[Clyde Porter IV]

Some info for you. Look at this diagram, look at your parts, carefully, and reassemble it the proper way. To answer your questions, and to access these parts we are looking at #8. This assembly is comprised of multiple small parts.

A digital camera or your cellphone, if it has a good close-up function, is always a good idea for documenting order of disassembly, for your reassembly. Good, close-up pictures ensure you're doing things properly, that you document the order of disassembly, they relieve anxiety and frustration, and ensure the reassembly is correct.

FYI, I suggest working in a tray, with a terrycloth liner, to keep parts from bouncing-away as you disassemble things. The tray helps to corral the various small pieces, the terrycloth deadens any 'bounce' from dropped parts, and I recommend something white instead of dark for the terrycloth, parts show-up better. Do one assembly at a time. If you get stuck because you doubt your abilities/memory, you have the factory shop manual, and three more slides in the other carbs to use as points of reference. Take your time. Get things clean. If you have an animal that likes to jump onto your work area, put them in another room, and shut the door.

There are large trays with snap-on lids you can use to secure the disassembled parts, if you have to interrupt your work efforts. WalMart, Target, or a kitchen supplies store, or the internet will have many choices. I suggest bigger is better.

Use a large-blade slot head screwdriver which snugly-fits the white nylon screw inside the slide, to remove the screw. There is a small spring underneath that. Be careful if you turn the slide upside down to remove that white nylon screw, as the spring could run and hide somewhere. It's better to keep the slide upright, and to use a pair of needle-nose pliers to remove things one at a time. First the white nylon screw, then the spring, then the needle.

If there is gunk on the needle, or if the carbs were left stored with gasoline in the float bowls, the needle may be held in-place by the sticky gunk. A shot of carb cleaner, then grabbing the top of the needle with the needle-nose pliers, a few back & forth movements of the pliers, and that sticky needle should pop out.

VMX12- Service-Manual.pdf (vmoa.net)

View attachment 82823

It's ~ 5-1/2 turns from the white nylon needle cap inside the diaphragm slide being snug. This does not need to be torqued-down excessively! Snug is fine.

View attachment 82824

This is a slide from a dirty set of carbs, you can see crud. The needle has a flat washer, a circlip, then a couple shim washers (they are stuck-together on this picture, two-up from the bottom needle in the picture) on this needle, and a thick nylon washer with an off-center *** on it which indexes into the black plastic diaphragm slide (the small hole to one-side of the center small hole).

To disassemble things, with the needle on your work area, use needle-nose pliers to remove the E-clip/circlip beneath the first flat washer, which should easily slide off, exposing the circlip. Be careful, as these, like the spring you already removed, like to run and hide when working with them. Should you lose it, Harbor Freight Tools sells an assortment of them, inexpensively, same for that tiny O-ring below the CV diaphragm cap, which often will stay in-place on the carburetor body as you remove the diaphragm cap, to begin your work with the slide and the needle, and their multiple small parts.

View attachment 82834

External Retaining Ring Assortment, 300 Pc. (harborfreight.com)

O-Ring Assortment Pack - 397 Piece Metric O-Ring Assortment (harborfreight.com) Less than $14 for both.

View attachment 82825View attachment 82827

Look at this picture, at 6 o'clock, you see a large hole, this allows controlled motion of the slide up and down as air passes through it. Directly above it, there is another hole, this is for the needle. Above that, is a yet-smaller hole, that is for the off-center *** of the needle nylon washer to index-into.

View attachment 82826

I suggest that when removing or installing the thick nylon washer with the off-center ***, on/off the needle, that you do it from the needle's tapered end. In other words, instead of trying to remove it from the top of the needle, where it rests, slide it down towards the taper. I've found that it comes-off easier going in that direction. Also a spritz of carburetor cleaner on the stuck-together parts will help loosening gummy bonding among parts.

When you use a pair of needle-nose pliers to insert the needle stack into the center needle hole, grab the needle as it emerges from the bottom of the slide, and gently, slowly rotate it, and you will feel the *** drop-into the small hole, and the needle drops several mm more. Now the spring goes on-top of that needle stack, and the white nylon screw plug screws in to secure the assembly. Snug that screw, you can strip it if you use too-much torque.

See the encrustations on the towel? That is enough material to plug a pilot jet! Use an aerosol carb cleaner to thoroughly clean all the pieces before reassembly, including the interior of the black plastic throttle slide. Hopefully, your diaphragm isn't torn, if it is, time for a replacement. You can try the by-themselves aftermarket diaphragms, or replace the entire slide and diaphragm, which is how Yamaha sells them.

Take your time, assemble things properly, use needle-nose pliers to insert to needle stack of pieces, then the spring, then the white nylon screw cap, and don't over-tighten it.

View attachment 82831

More-experienced members than I am, who can speak to issues of carburetion on a VMax are CaptainKyle, Sean Morley, dannymax, and Damon. Reach them for a PM under the Members tool. Note that the spelling and capitalization need to be exact for the search function to work.

Wow that awesome how far from Tennessee are lmao. All I did was pull the slide of #3 or back right if on the bike. It was stuck closed and Wow let me tell did that make difference hold the F—-k Henry I’m ready. Lol

the adjustment screw inside Said slide was huge, like size of dime

 

[Fire-medic]

Sounds like removing the CV carb caps (watch out for that tiny O-ring on the carburetor body beneath the CV carb cap!) and removing all the diaphragm slides to be cleaned with carburetor aerosol solvent and the slide bores, too (disassemble/re-assemble one at a time, please) would benefit your bike. The way I recall the piston bore order for the bike is the letter 'N.' Draw it like you were block-printing the capital letter:

lower-left to upper-left
upper-left to lower-right
lower-right to upper-right

Assuming the rider is in the saddle.

Like so-many topics on here, this has been mentioned before, by another member. Good things bear repeating as members come and go.

Now, check your carburetor synchronization, as it would be impossible to synch your carburetors properly if one slide was sticking.

Once it's all within-spec, intake-wise, you're gonna feel like Slim Pickens:
https://tvtropes.org/pmwiki/pmwiki.php/Film/DrStrangelove#video-link


As also mentioned, be sure that the tab on the CV slide diaphragm indexes into the carburetor body relief for it, or else you will have a tremendous vacuum leak. On used bikes I've bought, I've found more-than one pinched, out-of-place diaphragm: "the &^$#!!* bike doesn't run right!" Incompetent home-hack mechanics means otherwise-sound bikes sell cheap. Let's hope they didn't attempt to adjust the valve shims!

 

[Clyde Porter IV]

Some info for you. Look at this diagram, look at your parts, carefully, and reassemble it the proper way. To answer your questions, and to access these parts we are looking at #8. This assembly is comprised of multiple small parts.

A digital camera or your cellphone, if it has a good close-up function, is always a good idea for documenting order of disassembly, for your reassembly. Good, close-up pictures ensure you're doing things properly, that you document the order of disassembly, they relieve anxiety and frustration, and ensure the reassembly is correct.

FYI, I suggest working in a tray, with a terrycloth liner, to keep parts from bouncing-away as you disassemble things. The tray helps to corral the various small pieces, the terrycloth deadens any 'bounce' from dropped parts, and I recommend something white instead of dark for the terrycloth, parts show-up better. Do one assembly at a time. If you get stuck because you doubt your abilities/memory, you have the factory shop manual, and three more slides in the other carbs to use as points of reference. Take your time. Get things clean. If you have an animal that likes to jump onto your work area, put them in another room, and shut the door.

There are large trays with snap-on lids you can use to secure the disassembled parts, if you have to interrupt your work efforts. WalMart, Target, or a kitchen supplies store, or the internet will have many choices. I suggest bigger is better.

Use a large-blade slot head screwdriver which snugly-fits the white nylon screw inside the slide, to remove the screw. There is a small spring underneath that. Be careful if you turn the slide upside down to remove that white nylon screw, as the spring could run and hide somewhere. It's better to keep the slide upright, and to use a pair of needle-nose pliers to remove things one at a time. First the white nylon screw, then the spring, then the needle.

If there is gunk on the needle, or if the carbs were left stored with gasoline in the float bowls, the needle may be held in-place by the sticky gunk. A shot of carb cleaner, then grabbing the top of the needle with the needle-nose pliers, a few back & forth movements of the pliers, and that sticky needle should pop out.

VMX12- Service-Manual.pdf (vmoa.net)

View attachment 82823

It's ~ 5-1/2 turns from the white nylon needle cap inside the diaphragm slide being snug. This does not need to be torqued-down excessively! Snug is fine.

View attachment 82824

This is a slide from a dirty set of carbs, you can see crud. The needle has a flat washer, a circlip, then a couple shim washers (they are stuck-together on this picture, two-up from the bottom needle in the picture) on this needle, and a thick nylon washer with an off-center *** on it which indexes into the black plastic diaphragm slide (the small hole to one-side of the center small hole).

To disassemble things, with the needle on your work area, use needle-nose pliers to remove the E-clip/circlip beneath the first flat washer, which should easily slide off, exposing the circlip. Be careful, as these, like the spring you already removed, like to run and hide when working with them. Should you lose it, Harbor Freight Tools sells an assortment of them, inexpensively, same for that tiny O-ring below the CV diaphragm cap, which often will stay in-place on the carburetor body as you remove the diaphragm cap, to begin your work with the slide and the needle, and their multiple small parts.

View attachment 82834

External Retaining Ring Assortment, 300 Pc. (harborfreight.com)

O-Ring Assortment Pack - 397 Piece Metric O-Ring Assortment (harborfreight.com) Less than $14 for both.

View attachment 82825View attachment 82827

Look at this picture, at 6 o'clock, you see a large hole, this allows controlled motion of the slide up and down as air passes through it. This is the hole which is bored larger in the Dynojet Stage 7 carburetor jet kit directions. Directly above it, there is another hole, this is for the needle. Above that, is a yet-smaller hole, that is for the off-center *** of the needle nylon washer to index-into.

View attachment 82826

I suggest that when removing or installing the thick nylon washer with the off-center ***, on/off the needle, that you do it from the needle's tapered end. In other words, instead of trying to remove it from the top of the needle, where it rests, slide it down towards the taper. I've found that it comes-off easier going in that direction. Also a spritz of carburetor cleaner on the stuck-together parts will help loosening gummy bonding among parts.

When you use a pair of needle-nose pliers to insert the needle stack into the center needle hole, grab the needle as it emerges from the bottom of the slide, and gently, slowly rotate it, and you will feel the *** drop-into the small hole, and the needle drops several mm more. Now the spring goes on-top of that needle stack, and the white nylon screw plug screws in to secure the assembly. Snug that screw, you can strip it if you use too-much torque.

See the encrustations on the towel? That is enough material to plug a pilot jet! Use an aerosol carb cleaner to thoroughly clean all the pieces before reassembly, including the interior of the black plastic throttle slide. Hopefully, your diaphragm isn't torn, if it is, time for a replacement. You can try the by-themselves aftermarket diaphragms, or replace the entire slide and diaphragm, which is how Yamaha sells them.

Take your time, assemble things properly, use needle-nose pliers to insert to needle stack of pieces, then the spring, then the white nylon screw cap, and don't over-tighten it.

View attachment 82831

More-experienced members than I am, who can speak to issues of carburetion on a VMax are CaptainKyle, Sean Morley, dannymax, and Damon. Reach them for a PM under the Members tool. Note that the spelling and capitalization need to be exact for the search function to work.

Was pic’s Vmax

 

[Fire-medic]

Was pic’s Vmax

Yes, except for Slim Pickens (Major 'King' Kong).

 

[Clyde Porter IV]

Yes, except for Slim Pickens (Major 'King' Kong).

I think this thing has fresh carbs Too Clean

 

[Fire-medic]

Are you saying that the bike you have, or had recently-cleaned carbs? To my knowledge, a diaphragm slide shouldn't ever-stick in the bore, unless there were gummy deposits or grit from a dirty air filter, or no air filter, between the slide and the carburetor slide bore walls.

 

[Clyde Porter IV]

Are you saying that the bike you have, or had recently-cleaned carbs? To my knowledge, a diaphragm slide shouldn't ever-stick in the bore, unless there were gummy deposits or grit from a dirty air filter, or no air filter, between the slide and the carburetor slide bore walls.

It was clean as a whistle except for this: I took Carb cleaner and rubbed with rag: but yea the pics you posted gummed up I’m. Not sure why it would stick I’m assuming this enough to make it

 

[Clyde Porter IV]

Are you saying that the bike you have, or had recently-cleaned carbs? To my knowledge, a diaphragm slide shouldn't ever-stick in the bore, unless there were gummy deposits or grit from a dirty air filter, or no air filter, between the slide and the carburetor slide bore walls.
Would this be enough to make one hong up? Hell what do I know I’m not a Carb guy. I’m a Body Guy big difference lol

 

[Clyde Porter IV]

Tire picture accident thumb nails a just that

 

[Clyde Porter IV]

Sounds like removing the CV carb caps (watch out for that tiny O-ring on the carburetor body beneath the CV carb cap!) and removing all the diaphragm slides to be cleaned with carburetor aerosol solvent and the slide bores, too (disassemble/re-assemble one at a time, please) would benefit your bike. The way I recall the piston bore order for the bike is the letter 'N.' Draw it like you were block-printing the capital letter:

lower-left to upper-left
upper-left to lower-right
lower-right to upper-right

Assuming the rider is in the saddle.

Like so-many topics on here, this has been mentioned before, by another member. Good things bear repeating as members come and go.

Now, check your carburetor synchronization, as it would be impossible to synch your carburetors properly if one slide was sticking.

Once it's all within-spec, intake-wise, you're gonna feel like Slim Pickens:
https://tvtropes.org/pmwiki/pmwiki.php/Film/DrStrangelove#video-link
View attachment 82842

As also mentioned, be sure that the tab on the CV slide diaphragm indexes into the carburetor body relief for it, or else you will have a tremendous vacuum leak. On used bikes I've bought, I've found more-than one pinched, out-of-place diaphragm: "the &^$#!!* bike doesn't run right!" Incompetent home-hack mechanics means otherwise-sound bikes sell cheap. Let's hope they didn't attempt to adjust the valve shims!

Ummmmmm…… yea I seen the tab and little bitty O-ring bottom left what’s that whole for