Pilot Screw Setting

[corkman]

I have a 2003 VMAX and just cleaned the CARBs. I noticed that all four pilot screws were screwed all the way in. When I looked at the service manual it said they were "Preset". I thought that it was odd that they would all 4 be "preset" to all the way in, I am used to them being backed out 1-3 turns.
Anyone know what the initial setting should be, before I fine tune them once I get it running?

 

[davesax36]

It shouldn't run with the a/f screws all the way in (I don't think). Most of us go 2.5 turns out with stock pipes.

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[1st Shirt Maxer]

If your talking about the air/fuel mix screws below the diaphram cover, 2.5 turns out...

 

[corkman]

Good deal, let me go install the carbs now.
Thanks

 

[corkman]

Any idea why my post is not showing up on the Carb/tuning forum?

 

[06VMAXIMUS]

Any idea why my post is not showing up on the Carb/tuning forum?

I think you have posted 3 of them....

 

[sdt354]

Good deal, let me go install the carbs now.
Thanks

That's a good starting point and will get you running ok. I always sync, then idle down low so I can hear the engine response. I want to hear the engine stumble when I turn each screw in to almost seated. Then off for a tuning ride with a little screw driver. I end up about 2 3/4 + OR - a slight 1/16 of a turn out-70 degree weather at 6 ft. above sea level. The setting will effect low end, and some midrange performance.
Marks 4-2 exhaust. Carbs stock. Air box Y shimmed 3/8.
Steve-o

 

[tugla]

what ya running for jets steve ????

 

[sarchin]

That's a good starting point and will get you running ok. I always sync, then idle down low so I can hear the engine response. I want to hear the engine stumble when I turn each screw in to almost seated. Then off for a tuning ride with a little screw driver. I end up about 2 3/4 + OR - a slight 1/16 of a turn out-70 degree weather at 6 ft. above sea level. The setting will effect low end, and some midrange performance.
Marks 4-2 exhaust. Carbs stock. Air box lid shimmed 3/8.
Steve-o

how do you shim the air box lid? I took the "Y" off my airbox, is shimming the lid similar or allow a little more air through?

 

[sdt354]

what ya running for jets steve ????

150's Rov. I could go just a bit smaller on the mains or find a way to get more air. But, I've got a set of stage 7 carbs to put on, with pods using 2 -1/2" stacks, so I'll be able to get the air I want. If I don't like the pods, I'll switch to Sean's box lid. I like to run a bit lean on the mains, fatter on the needles within reason.

 

[sdt354]

how do you shim the air box lid? I took the "Y" off my airbox, is shimming the lid similar or allow a little more air through?

Sorry about that, I shim the Y not the lid. I use 3/8" plastic bushings from ACE hardware and longer screws. This seems to work better midrange for me than taking the Y off. A little free horse power.

 

[sarchin]

Sorry about that, I shim the Y not the lid. I use 3/8" plastic bushings from ACE hardware and longer screws. This seems to work better midrange for me than taking the Y off. A little free horse power.

That's a good idea...I could tell taking the Y off helped, but the midrange when I open it up sounds like it's getting too much air for a couple of seconds. I'm going to get some bushings and try it out...



and sorry for getting off track on this tread for a minute :worthy:

 

[tugla]

150's Rov. I could go just a bit smaller on the mains or find a way to get more air. But, I've got a set of stage 7 carbs to put on, with pods using 2 -1/2" stacks, so I'll be able to get the air I want. If I don't like the pods, I'll switch to Sean's box lid. I like to run a bit lean on the mains, fatter on the needles within reason.

150 mik or dj

 

[D-Max2012]

Air box Y shimmed 3/8.

What is this "Shimmed" you mention??? Just curious..

 

[davesax36]

Some guys raise the "Y" section of the air box with washers or a spacer of some sort.

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[sdt354]

150 mik or dj

Mikuni's Rov.

 

[sdt354]

What is this "Shimmed" you mention??? Just curious..

Instead of removing the Y. It is lifted up against the lid.
Steve-o

 

[D-Max2012]

Shimmed.. Really? To let more air in?
I find that my stock air box takes power away from my bike if I leave it as is.. I have to block off about 1/2 inch on each side, with duct tape, in order for my bike to pull with any kind of power. Stock Pipes, Stock jets 1 and 3 (152.5) - 2 and 4 (150) Mikuni jets.
F.P. Needles at center position (3rd down from blunt end).

 

[sdt354]

Shimmed.. Really? To let more air in?
I find that my stock air box takes power away from my bike if I leave it as is.. I have to block off about 1/2 inch on each side, with duct tape, in order for my bike to pull with any kind of power. Stock Pipes, Stock jets 1 and 3 (152.5) - 2 and 4 (150) Mikuni jets.
F.P. Needles at center position (3rd down from blunt end).

With stock exhaust, carb or airbox mods are a bad idea, and everything should remain stock. A full exhaust system is the first performance mod needed before doing any of the mentioned other stuff. I think taping off your box inlets is masking another problem. Most likely a vacuume leak. Cracked boots are a good place to start. A well tuned stock bike in good condition will pull very well.
Steve

 

[D-Max2012]

Steve, I agree from the positive things I've always read about the Max for years now. I got the bike last year to offset some of the cost of taking the car into work. The boots are 3 weeks old, old ones were all cracked up.. Checked all over for leaks, could not find any.. Tried it with WD-40 then again with Propane gas.. No change in RPM.
What I could find on the bike that is modded was:
The exhaust is modified stock. The previous owner took off the end cap baffles. The Needles are the F.P ones in photo.
The PO did have 3 Mukuni 118 mains and 1, DJ 120 in there which made the bike run horribly.
Now at least I can ride it to work but I would like it to have full power without any air box mods. I've check compression, all within specs. I've changed plugs and gapped them to specs. All float levels at 17mm from mid carb marking. Synched up carbs within 1mm of each other.



When I take the tape off, she stumbles in 2nd around 3K, no top end at all- Almost dies. With the tape, I feel a light hesitation around 4th and 5th but pulls hard. Last weekend (with the tape mod), was the 1st time I felt the V-Boost kick in.. Good lord!!!:hippy biker: