Carb Diaphragm cover removal

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HeckticHaze

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I have attempted to perform the shotgun procedure on all 4 carbs. The #1 carb I have been unable to get two of the diaphragm cover screws out. I purchased a 3/8" impact driver and a #2 JIS bit. I tried a number of times with the driver with no success. I don't want to keep hitting the screwhead and take a chance of damaging the carb body. I used Kroil oil on the screws hoping that would loosen the screw. Tried tightening then loosening. Tried to get a pair of vice trips on the screw head but no room to turn the vice grip. Any suggestions before I start drilling and try an easy out screw extractor? The screw heads are pretty worn. I wish I had a JIS rachet bit. Have not been able to find one.
 

desert_max

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That impact driver is your master key. The bodies will take a pretty good whack, just don't use your BFH. What is needed is a couple of good shocks to break the bond between the screw and the body.

I have had the same impact driver roughly 30 years. I don't think it has ever failed me.
 

Fire-medic

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At this point use a Dremel tool, w/an abrasive disc to cut a blade screwdriver slot into the screw head. Take your time, and cut it to make a tight-fit for the blade in the cut you make. I usually cut to the same depth as the bottom of the phillips X. DO NOT try to cut an X to make your own phillips! Trial-fit your blade into the screw head, make-sure that you have a tight fit for the screwdriver blade, and that it's the same width as the head of the screw; once you're satisfied w/your blade fit, give it a couple light blows with a hammer. You're NOT driving a 16d common nail into a 2x4, you're trying to shock the screw loose. You should be able to easily loosen the screw now. I've never not been able to loosen a VMax CV diaphragm cover using this method, take your time, and git 'er done!

You don't need a JIS screwdriver.

Could you be a bit-more specific in your location? "Upstate NY" to someone in Nassau, Suffolk, or the 5 boroughs, is Westchester County and anyplace north of that. Are you in the Hudson River Valley; north of Albany, somewhere along the I-87 corridor, through the Adirondacks to Canada and Autoroute Quinze; somewhere in the Finger Lakes and the Southern Tier, perhaps by Binghamton, by the home of Glenn Curtiss, in Hammondsport, 'Fastest Man Alive' in the air or on the ground (on a motorcycle, now in the Smithsonian); around Rochester (once the Flour City, because they supplied much of the ground flour for the country in the 1800's, now the Flower City because of the May Lilac Festival) or points west like Buffalo?

You have some great resources 'upstate,' Schenectady and Rochester have VMax specialists who can fix any issue you may have.

https://www.facebook.com/PCW-Racing-Inc-598910693460082/ Schenectady

LCR Performance
560 Avis St, Rochester, NY 14615
Phone: (585) 458-8185
Hours:
Closed ⋅ Opens 8AM Mon
Monday 8AM–5PM
Tuesday 8AM–5PM
Wednesday 8AM–5PM
Thursday 8AM–5PM
Friday 8AM–5PM
Saturday Closed
Sunday Closed
 
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HeckticHaze

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Guys, thank you for your input. I went back and took a 1/4" socket, on a 3/8" ratchet, put a #2 JIS bit in, and I got one of the screws out. The other screw did not budge and the screw head is a mess. The Dremel it is. When I put the machine screws back in they are going to be SS allen heads with antisieze on them. Used them on the 1982 Seca 750 carb rebuild. Never had an issue removing the machine screws since.

I should probably do this in another thread but have any of you used a Gunson colortune plug to tune a Vmax? I use one for my Seca. It gets you in the ball park. I usually still have to do some tweaking from there.
 

Fire-medic

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Vice grips work well
Envy is the desire for others' traits, status, abilities, or situation.

Gluttony is an inordinate desire to consume more than that which one requires.

Lust is an inordinate craving for the pleasures of the body.

Anger is manifested in the individual who spurns love and opts instead for fury. It is also known as Wrath.

Greed is the desire for material wealth or gain, ignoring the realm of the spiritual. It is also called Avarice or Covetousness.

Sloth is the avoidance of physical or spiritual work.

I lust-after, and am envious-of, being one-of those who easily-remove CV cap phillips screws, I'm no glutton for punishment, fighting-with stubborn screws, which makes me angry; I'm willing to do the work, I'm not slothful, but I covet having the ability to quickly remove those pesky screws!

That said, I've used a pair of 10" straight-jaw Vise-Grips successfully on the CV cap phillips screws, too. Especially for the anti-tamper screws. Take your time, get a good purchase, and you only have to get the screw to move a few degrees, to be able to remove it once the torque is loosened.

Vise-Grip.png
 

desert_max

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And nothing, NOTHING is more satisfying than the sound and feel of one of those miserable aforementioned fasteners breaking loose so that you can remove it - regardless of the method that you finally have to resort to...
 

dannymax

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Another good method is a sharp chisel at a 45 deg angle on the outside edge of the screw...this takes a little practice but is very effective.
 

dannymax

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Envy is the desire for others' traits, status, abilities, or situation.

Gluttony is an inordinate desire to consume more than that which one requires.

Lust is an inordinate craving for the pleasures of the body.

Anger is manifested in the individual who spurns love and opts instead for fury. It is also known as Wrath.

Greed is the desire for material wealth or gain, ignoring the realm of the spiritual. It is also called Avarice or Covetousness.

Sloth is the avoidance of physical or spiritual work.

I lust-after, and am envious-of, being one-of those who easily-remove CV cap phillips screws, I'm no glutton for punishment, fighting-with stubborn screws, which makes me angry; I'm willing to do the work, I'm not slothful, but I covet having the ability to quickly remove those pesky screws!

That said, I've used a pair of 10" straight-jaw Vise-Grips successfully on the CV cap phillips screws, too. Especially for the anti-tamper screws. Take your time, get a good purchase, and you only have to get the screw to move a few degrees, to be able to remove it once the torque is loosened.

View attachment 71888
I found the Torx socket for these at the local Ace store, believe it was a Craftsman brand.
 

Fire-medic

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I found the Torx socket for these at the local Ace store, believe it was a Craftsman brand.
I've done the brake disc button screws w/a cold chisel before. My security screwdriver tips I got in a set from Harbor Freight. I have 2 Ace Hardware stores by me, I'm all the time in-there for stuff to do projects.
 

HeckticHaze

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A Dremel is a wonderful thing. I cut a slot in the existing screw head and used the largest slotted screwdriver I own. I few hits with a hammer and the screw finally let loose. Finished the shotgun procedure. I need to find a tuning procedure post to make adjustments to the air/fuel mixture screws. Thank you everyone for your help.
 

Zeus36

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From Mr. Justin Lassy:

Low Speed Carb Adjustments
Low Speed Carb Tuning

Justin Lassy

The fuel mixture screws are indeed located behind the brass plugs. The brass plugs must be removed to access the screws. Be *very* careful about drilling out the plugs-use a drill stop. If you hit the screws with the drill bit, even for a moment, you risk running the screw down hard against its seat, destroying the screw and possibly the carb seat. Bad.

The fuel mixture screws deal w/ mixture at idle and a little bit above idle. They will determine off idle throttle response and extremely low idle cruising. Turn screws in to lean the mixture out, turn them out to richen the mixture.

Here are some rough guidelines to determine if you are running rich or lean at various rpm's. Examining the plugs is really the best way to get accurate results, but these guidelines will help you shoot for a direction (leaner or richer).

Idle and off idle

Lean condition: Poor off idle throttle response, idle that flutters a little after a throttle blip then slowly returns to the idle that you've set, popping back through the carbs when the throttle is blipped.

Rich condition: Off idle response may be good unless plugs are fouled from a way too rich mixture. After a throttle blip the motor will dive down below set idle and will either die if way too rich or may return to set idle if it can recover.

Adjustments

To adjust, run the motor until warm and idle is stable. Turn each screw in, one at a time, until the engine stumbles, then back the screw out until just rich of peak idle (idle drops again). Then turn them back in to peak idle. Repeat for each carb. If your screws are out more than 3 turns, the jet probably needs to be swapped to the next larger. The final position should be around 2.5 turns out on a stock set-up bike.
 

HeckticHaze

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Justin, Thank you for the low speed carb adjustment procedure. May be a few weeks until I get to perform the carb tuning. I'll get back on my progress.
 

HeckticHaze

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Got to do a little work on the carbs over the 4th. The idle is a lot better since the shotgun procedure. I had put new plugs in when I did the shotgun. Not happy with the color. Lilly white. Set the A/F screws back to what they were before performing the shotgun. The original plugs looked pretty good but really corroded. When I tried the tuning procedure I was sent I really can't hear a change in the engine until the A/F screw is turned way in or back them way out. The same for all 4 A/F screws. Maybe I just don't have the ear to hear this change in engine operation. Going to get the hand propane bottle out and check for vacuum leaks.
 
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