General

[1SK14R]

Let us know how it turns out. Here is info from this forum that was converted to a PDF about how to sync carbs.

The info you provided is GREATLY APPRECIATED.
I just learned once again something I didn’t know and was doing wrong the first time I was syncing the Vmax Carbs.
Cannot thank everyone enough for the Helpful Advice. Thank You Traumahawk , And Everyone Else for your Help .

 

[Fire-medic]

You should read the factory manual front to back. The first 64pp are annual updates, 'Supplements.' After that becomes the entire bike, system by system. The Appendix contains nuggets like sizes of fasteners, their torque values, and where they are on the bike.

There are directions for routing the cables, the hoses, and info on the VBoost actuation: when it starts, how-many rpm's to build to fully-open, and its components.

Having a color-coded wiring diagram helps in diagnosing something needing attention. The service manual shows color codes for wires, but I find it easier to refer to an actual color picture of the wiring diagram, for whichever model you have. Generally, it falls between 1985-'89, and 1990-2007. That's primarily because of the ignition the '85-'89 has 2 pickup coils by the stator, while the 1990-'07 are a single pickup coil. I believe at 2003 there is a difference after that for wiring to the instrument cluster, Sean Morley has mentioned about that, try the search function if your bike falls around that date.


Below, 1990-2003:

 

[1SK14R]

You should read the factory manual front to back. The first 64pp are annual updates, 'Supplements.' After that becomes the entire bike, system by system. The Appendix contains nuggets like sizes of fasteners, their torque values, and where they are on the bike.

There are directions for routing the cables, the hoses, and info on the VBoost actuation: when it starts, how-many rpm's to build to fully-open, and its components.

Having a color-coded wiring diagram helps in diagnosing something needing attention. The service manual shows color codes for wires, but I find it easier to refer to an actual color picture of the wiring diagram, for whichever model you have. Generally, it falls between 1985-'89, and 1990-2007. That's primarily because of the ignition the '85-'89 has 2 pickup coils by the stator, while the 1990-'07 are a single pickup coil. I believe at 2003 there is a difference after that for wiring to the instrument cluster, Sean Morley has mentioned about that, try the search function if your bike falls around that date.

Below, 1990-2003:
View attachment 95156

 

[1SK14R]

Thank You .
VBoost will be the next issue I Will tackle after I get it running 100% .
Believe it is the Module.
But have got a Reverse Polarity switch I will install to control VBoost for right now .
Thanks Again

 

[Traumahawk]

Thank You .
VBoost will be the next issue I Will tackle after I get it running 100% .
Believe it is the Module.
But have got a Reverse Polarity switch I will install to control VBoost for right now .
Thanks Again

You will become friends with something called the "mod monkey" that will be more than happy to spend your money. The Vmax community is great, and don't hesitate to reach out of you need help or have a question.

 

[1SK14R]

You will become friends with something called the "mod monkey" that will be more than happy to spend your money. The Vmax community is great, and don't hesitate to reach out of you need help or have a question.

Thank You

 

[gentsvmax]

I had Dan Unwic do mine . Was referred by Morley Muscle .
New Boots ,Totally Rebuilt and Sonic Tanked .
I have a battery in there that was from my Zx14r which is a 14 and the Max calls for a 16
And I’m wondering if maybe the battery is going south. Everything lights up , Starts up fine . But when you accelerate. You can really feel and hear the sputtering and was popping yesterday when drove .
I’m just trying to cover all bases .
All vacuum lines are good . I’m going to drain the carbs and see if anything ones out besides gas .
Another thought was maybe Pulse coil where the stator is ?

Did you sync the carbs after you installed them?

 

[1SK14R]

Did you sync the carbs after you installed them?

 

[1SK14R]

No , I am syncing them this weekend . And will see what the outcome is .

 

[Fire-medic]

Work yesterday, making the lion roar. Working through to the final adjustment. Much-better!



The bourdon tube gauges like these do a decent job of synchronization. Less messy than the dangerous mercury gauges or the blue-water capillary tubes. I have a Motion Pro set of those, but they don't get much use.

My set I first bought like these, I've had for probably 42 years. I bought them from JC Whitney, back when they still sent by USPS a newsprint catalog of 100+ pages, and where you could buy parts for Packards, DeSotos, Kaisers, and other now-orphan cars.

 

[1SK14R]

Work yesterday, making the lion roar. Working through to the final adjustment. Much-better!

View attachment 95165

The bourdon tube gauges like these do a decent job of synchronization. Less messy than the dangerous mercury gauges or the blue-water capillary tubes. I have a Motion Pro set of those, but they don't get much use.

My set I first bought like these, I've had for probably 42 years. I bought them from JC Whitney, back when they still sent by USPS a newsprint catalog of 100+ pages, and where you could buy parts for Packards, DeSotos, Kaisers, and other now-orphan cars.

Did mine awhile ago . They weren’t out to bad , But did need readjusting.
Test ran , Way Better, but from low rpm acceleration to around 4 or 4500 Sputtering and around 5or 6 above pulls like a train .
Wasn’t expecting that ,and that was without VBoost .
Have a switch that I control it with .
Been Aloooong time 35 years I drove a Vmax
Had a relaxed grip and when it started ripping in upper rpms “ POWER SMILE “ and startled me , almost lost my grip .
And it did pop a few times and I didn’t notice it after that .
But you can Sure hear the Valves .
Beginning to wonder if Valve Adjustment is in Need .

 

[1SK14R]

Did mine awhile ago . They weren’t out to bad , But did need readjusting.
Test ran , Way Better, but from low rpm acceleration to around 4 or 4500 Sputtering and around 5or 6 above pulls like a train .
Wasn’t expecting that ,and that was without VBoost .
Have a switch that I control it with .
Been Aloooong time 35 years I drove a Vmax
Had a relaxed grip and when it started ripping in upper rpms “ POWER SMILE “ and startled me , almost lost my grip .
And it did pop a few times and I didn’t notice it after that .
But you can Sure hear the Valves .
Beginning to wonder if Valve Adjustment is in Need .

That is The Set Up “ Synchronizer “ I have as well .

 

[1SK14R]

Work yesterday, making the lion roar. Working through to the final adjustment. Much-better!

View attachment 95165

The bourdon tube gauges like these do a decent job of synchronization. Less messy than the dangerous mercury gauges or the blue-water capillary tubes. I have a Motion Pro set of those, but they don't get much use.

My set I first bought like these, I've had for probably 42 years. I bought them from JC Whitney, back when they still sent by USPS a newsprint catalog of 100+ pages, and where you could buy parts for Packards, DeSotos, Kaisers, and other now-orphan cars.

 

[1SK14R]

I asked Dan of his opinion about TxSuperbikes in Dallas,Tx on Valve Adjustment Price . Which was estimated at $750.00 ( 4 1/2 ) hour job .
I would like to ask yours as well .
Is that about right ?

 

[Fire-medic]

That's ~$83 an hour, which these days, isn't too-bad for quality mechanical work. Pretty-good, if you look at what the dealership would charge. Maybe some competent member in the Dallas area would be available?

That shop, is it a dealer, or an independent shop? Are there a lot of good-looking rides in there, being serviced? Is the shop clean? What are remarks on social media for their work?

 

[1SK14R]

I don’t know if you know all the hype about “ GixxerBrah” buts that’s how I found out about them .
They work on ANY bikes , Dyno Tune , Service .
They have some BMW1000rr, R1, Busa’s, And 14r’s , Saw some Harley’s . Independent. Not a Dealership.

I’ve done everything that I can think of except Pulse Coil where the Stator is .
I do need to put the correct battery in there . I’ve got the Zx14r battery in there which is a 14
Max calls for a 16

Let me see ,
New Gas Tank “Used-EBAY”
New Fuel Filter
New Sparkplugs
Replaced Rear Coils-Wires-Caps
Replaced Front Wires-Caps
Ohms in Speck
Full Rebuild on Carbs. Thanks Dan !
Air Filter Like New
Fresh Oil - Filter

But as mentioned- she pulled HARD on the upper Rpm’s
I feel like I’m missing something small
Because it runs way better than before after Sync .
Just that lower rpm Sputter

I keep aiming towards the Valves

 

[Fire-medic]

If it's popping-back thru the carbs at lower speeds and trailing throttle, where the revs are >4K, that's a lean condition. Try tuning the air bleed screws below the CV caps. OEM, they have aluminum plugs on 'em, "no user serviceable adjustments behind me!" But it's to maintain the OEM settings so they meet the EPA specs approved at the time of production.

Normally they should be set at something like 2-3/4 turns from turned-in snug, not tight. Maybe 3 turns. Tuning those to achieve the highest rpm after doing a carb synch properly should increase throttle response and eliminate lean-popping.

 

[1SK14R]

If it's popping-back thru the carbs at lower speeds and trailing throttle, where the revs are >4K, that's a lean condition. Try tuning the air bleed screws below the CV caps. OEM, they have aluminum plugs on 'em, "no user serviceable adjustments behind me!" But it's to maintain the OEM settings so they meet the EPA specs approved at the time of production.

Normally they should be set at something like 2-3/4 turns from turned-in snug, not tight. Maybe 3 turns. Tuning those to achieve the highest rpm after doing a carb synch properly should increase throttle response and eliminate lean-popping.

Coming from the Exhaust.
But I noticed it a few times only .

 

[1SK14R]

If it's popping-back thru the carbs at lower speeds and trailing throttle, where the revs are >4K, that's a lean condition. Try tuning the air bleed screws below the CV caps. OEM, they have aluminum plugs on 'em, "no user serviceable adjustments behind me!" But it's to maintain the OEM settings so they meet the EPA specs approved at the time of production.

Normally they should be set at something like 2-3/4 turns from turned-in snug, not tight. Maybe 3 turns. Tuning those to achieve the highest rpm after doing a carb synch properly should increase throttle response and eliminate lean-popping.

 

[1SK14R]

Coming from the Exhaust.
But I noticed it a few times only .