4 turns out on the mixture screws---need to change PAJ-1?

[Vmaxattacks]

I have a bone stock '94 Cal. bike with 11K miles on the clock and nothing more than drilled cans for the sound. I have always concluded that this is a weak bike after reading all of the NUMEROUS posts from the other Vmax owners' well running bikes (sighing) but nonetheless it runs "okay" but not astonishing. I did the "T" boost mod several years ago but I still mostly use the factory setting (thankfully I put a toggle switch on the mod.)just because I am not sending the v-boost components to an early demise. At one point I had the Cobra slip-on's and the Dynojet stage 1 kit (big mistake) but I crap-canned that mess and went back to stock. The looks never justified the loss in an already taxed power curve. All of the stock components are back in --correctly--, new, undrilled slides, the floats are ALL at 17mm and the sync. is spot on. I have always been jealous of you guys with the "lumpy" idle...my bike has never seen that and never will I guess
I have meticuously maintained this bike but in order to get a "smooth" idle I have to back out the idle mix screws to around 4-turns. I have read and re-read the mixture procedure so many times it is etched into my memory. But, I do not get the "noticeable" change in idle quality as everyone eludes to until I get in the neighborhood of around the 4-turn mark and then again only one cylinder is markedly different than the rest. These carbs, as most of you know, have #100 super "BN" jets in the PAJ-1 holes. In order to pin down the idle with LESS turns out from the bottom are these the ones I need to swap to a #90.
I realize that my carbs, cams, etc. all are because I have to contend the bureaucratic BS here in the "Golden State" and am stuck with them unless I want to shell out BIG $$ to correct this which I am not willing to do but is there a little something I can do to circumvent the situation?
I have read some posts that others have posted that say they too have 4-5 turns out but this seems alittle too much (for my taste) from the "baseline" of 2-2 1/2 turns.
Thanx in advance,
Bud Weaver

 

[4gasem]

I have a bone stock '94 Cal. bike with 11K miles on the clock and nothing more than drilled cans for the sound. I have always concluded that this is a weak bike after reading all of the NUMEROUS posts from the other Vmax owners' well running bikes (sighing) but nonetheless it runs "okay" but not astonishing. I did the "T" boost mod several years ago but I still mostly use the factory setting (thankfully I put a toggle switch on the mod.)just because I am not sending the v-boost components to an early demise. At one point I had the Cobra slip-on's and the Dynojet stage 1 kit (big mistake) but I crap-canned that mess and went back to stock. The looks never justified the loss in an already taxed power curve. All of the stock components are back in --correctly--, new, undrilled slides, the floats are ALL at 17mm and the sync. is spot on. I have always been jealous of you guys with the "lumpy" idle...my bike has never seen that and never will I guess
I have meticuously maintained this bike but in order to get a "smooth" idle I have to back out the idle mix screws to around 4-turns. I have read and re-read the mixture procedure so many times it is etched into my memory. But, I do not get the "noticeable" change in idle quality as everyone eludes to until I get in the neighborhood of around the 4-turn mark and then again only one cylinder is markedly different than the rest. These carbs, as most of you know, have #100 super "BN" jets in the PAJ-1 holes. In order to pin down the idle with LESS turns out from the bottom are these the ones I need to swap to a #90.
I realize that my carbs, cams, etc. all are because I have to contend the bureaucratic BS here in the "Golden State" and am stuck with them unless I want to shell out BIG $$ to correct this which I am not willing to do but is there a little something I can do to circumvent the situation?
I have read some posts that others have posted that say they too have 4-5 turns out but this seems alittle too much (for my taste) from the "baseline" of 2-2 1/2 turns.
Thanx in advance,
Bud Weaver

Can't help ya a bunch but I am sure Shawn Kloker can... He LOVES working on carbs...:whistlin:

I am running 4 turns out with stage 1 and a full exhaust system so to me, that sounds like a lot for a pretty much stock bike...:ummm:

Good luck,
Chris

 

[maleko89]

Every bike/carb is different so I wouldn't worry about how many turns your mixture screws are turned out. Unless, they're more than say 4.5 turns. If you take a mixture screw out you can see how fine the threads are.....so 1 turn isn't really that much.

Mine range from 2.5 to 4.5 turns. Valve adjustment has an affect too. I have US49 idle circuit configuration of:

PAJ1: Mikuni 90
PAJ2: Mikuni 170
PFJ: Mikuni 37.5

Mark
#1098

 

[Vmaxattacks]

Thanx, guys.

Y' know, it just shows to go ya that you should'nt fix what 'aint broke. One of the dumbest things I did for this bike was the Cobra slip-on/jet kit route. Yea, it looked good, but you felt it in the "seat of the pants" for sure.

I had contemplated going to see Mark for one of his exhaust systems but then again, in order to "fully" take advantage of a good, free-flowing exhaust system, that entails lots of work and $$ and I just don't want to f**k with it any more.

I have done LOTS of research, i.e. shimmed needles, tied slide springs coils, jets, this, that and the other, and I still derive the same conclusion....Yamaha engineers know more than I do!

I should have done my homework back in December of '93 and should have just stepped into one of the neighboring states and bought this damn bike there:bang head: :bang head:

I am going to buy some 90's for the hell of it and do a little playing.

Thanx

 

[shawn kloker]

When my mixture screws were out too far,I went to 42.5 pilot fuel jets.Got them back in there.After 5 turns they can fall out.

It almost sounds like you are running on 3 cylinders or some one has the cam timing off.Did you buy this bike new or used?

Is the vboost cable slack adjusted properly?Check the spark at all four plugs.Compression test?

All the Caleeforneeah(as Arnold says it)bikes that I have seen ran very well,probably only a few ponies less.

 

[maleko89]

conclusion....Yamaha engineers know more than I do!

Exactly! A properly tuned stock bike is hard to beat!

Mark
#1098

 

[Vmaxattacks]

Bought it new in late '93. I am the only rider and I have done all the wrenching myself.
I put in new NGK's about 500 miles ago. All the carbies are clean and I "shotgun" them regularly. I had an UNI filer in it but put back in my old paper one for the time being (runs the same BTW). I Have never been crazy about an oiled gauze or foam filters and I never use them in my race cars either.
Checked the valve lash when I did the plugs..all within spec. It pulls hard when I ride it for sure and there are no surging issues or "transition" maladies. It just seems to me that I can fatten up the idle mix a bit more because as I start to "creep" up on the screws I am running out of tension on the mixture screw springs not to mention the screw threads themselves. This is a very cold-blooded Max and what I have read from others' my bike is not uncommon either. Living in Southern California I have ALWAYS had to start my bike in the morning with the "choke" but I pull it down right away to about 1/8th of it's use and I ride for several minutes with it applied before I pull it off and then the bike will idle more steadily and stay that way for the duration. I just know from experience that I can get a smoother transition from idle into low/midrange by fattening up the idle discharge and I want to make sure I am "playing" with the correct, most attributable jet, for the idle circuit.

So, what you are saying, is NOT the PAJ-1's but the PJ's correct?
I have the stock 37.5's right now.
Thanx!

 

[4gasem]

Exactly! A properly tuned stock bike is hard to beat!

Mark
#1098

+1 to that...

I would love some flat slides or F.I. but I really don't want to F with it all...:bang head:

It's a lot of trial and error...

My SV was as easy as hooking it to a PCIIIusb and plugging a computer into it and telling it what I wanted... Me likey that kind of tuning...:thumbs up:

 

[shawn kloker]

Bought it new in late '93. I am the only rider and I have done all the wrenching myself.
I put in new NGK's about 500 miles ago. All the carbies are clean and I "shotgun" them regularly. I had an UNI filer in it but put back in my old paper one for the time being (runs the same BTW). I Have never been crazy about an oiled gauze or foam filters and I never use them in my race cars either.
Checked the valve lash when I did the plugs..all within spec. It pulls hard when I ride it for sure and there are no surging issues or "transition" maladies. It just seems to me that I can fatten up the idle mix a bit more because as I start to "creep" up on the screws I am running out of tension on the mixture screw springs not to mention the screw threads themselves. This is a very cold-blooded Max and what I have read from others' my bike is not uncommon either. Living in Southern California I have ALWAYS had to start my bike in the morning with the "choke" but I pull it down right away to about 1/8th of it's use and I ride for several minutes with it applied before I pull it off and then the bike will idle more steadily and stay that way for the duration. I just know from experience that I can get a smoother transition from idle into low/midrange by fattening up the idle discharge and I want to make sure I am "playing" with the correct, most attributable jet, for the idle circuit.

So, what you are saying, is NOT the PAJ-1's but the PJ's correct?
I have the stock 37.5's right now.
Thanx!

That is how I richened up my idle screws,went to 42.5's pilot fuel jet.I also just ported mine and put .383 lift cams in.Went to bigger mains too.Now I'm starting all over trying to tune my 41mm FCR's.

 

[maleko89]

Put 90's in PAJ1 in place of your 100's. That'll richen you up and allow you turn turn the screws in some.

You could try going to Mikuni 40's for the pilot fuel jet. Your mileage will go down some though and I'm not sure if that's really necessary. What's wrong with having the screws out 4 turns?

Mark
#1098

 

[vmaxattack]

Mark,Then you would have 4 screws loose!

 

[maleko89]

lol, right on!

 

[vmaxattack]

Make that 5!

 

[Vmaxattacks]

. What's wrong with having the screws out 4 turns?

Mark
#1098

.......Because I can "feel" the idle smoothing out nearing the end of the screw limit so I want to tighten up the range to see if I can hone in on it. It always had a "rythmic" idle and not a defined lumpier idle as I have heard so many others posess. Granted, I have an all stock bike with nothing more than drilled cans (3/8" @ the rivet holes and no end plate) and some I have heard were jetted and piped which were a f**k of alot better sounding than mine. My bike has ALWAYS sounded like this.

For instance; if I am sitting in the driveway in neutral with it fully warmed up I can start to just crack the throttle blades and ease into it gradually and any engine speed under 2-grand just sounds sloppy and not smooth. Past that it is fine. Today, for example, I went out for a ride during lunch to the local bike supply to pick up some Engine Ice, Water Wetter and four #90 jets. I turned on the T-boost and from a barely-rolling start in first I stabbed the throttle (no clutching) and it jumps like a mofo and I have to lean forward to keep the front wheel from getting too high!

It does run good. just this anoying idle that bugs the piss outta me. Maybe it's just a characteristic trait of this Max but it is just anoying none the less. Seems to me that it should be les rythmic and more "pronounced" for a muscle bike.

Guess I am too used to the roar of the 572 Hemi in my '69 Super Bee:hmmm:

 

[maleko89]

Understood.

Install the 90's. The jets you have in there now are four sizes larger than the US49 PAJ1 jet. I'm sure you'll notice a better idle.

I would also pull the slides and clean the three purge jet holes. If one of these is plugged the idle will sound a bit rough. Two of the holes are near the pilot screw hole....one with an o-ring and the other with a brass nub blocking most of it. The other is behind the slide and is at about the 6:00 position. You can tell they're plugged if you see a pooling of fuel behind the diaphragm. Use a small straw and suck. If unable, it's clogged.

Mark
#1098

 

[red98vmax]

Sure would like a picture with more details, like the lvlhead shotgun instructions have. Not that your description wasn't good, I just like pictures with colored circles and arrows.

Steve

Understood.

Install the 90's. The jets you have in there now are four sizes larger than the US49 PAJ1 jet. I'm sure you'll notice a better idle.

I would also pull the slides and clean the three purge jet holes. If one of these is plugged the idle will sound a bit rough. Two of the holes are near the pilot screw hole....one with an o-ring and the other with a brass nub blocking most of it. The other is behind the slide and is at about the 6:00 position. You can tell they're plugged if you see a pooling of fuel behind the diaphragm. Use a small straw and suck. If unable, it's clogged.

Mark
#1098

 

[maleko89]

Here ya go!

Red circle=purge jet #1 (inside hole)
Blue circle=purge jet #1 (outside hole)
Green circle=purge jet #2

Mark
#1098

 

[red98vmax]

Thanks Mark.

I'll have to check on mine when I've got it apart next time. Put a small straw over the holes and suck (air I hope) or they are blocked? Any ideas how to clean if blocked? Push wire through, compressed air, carb cleaner, ...? One of these winters I'll have to tear them down, but not yet.

 

[maleko89]

You're welcome!

Correct, if you're unable to blow air through...clogged.

Honda carb cleaner has always worked for me. Other folks use a small gauge wire to clean it. That should only be necessary if the carbs or bike have been unused for a long period of time.

Mark

 

[Vmaxattacks]

View attachment 1019Where your blue circle is just an access plug, correct? Because I had to drill into one of these to dislodge a piece of crap that was plugging up the orifice behind it.

SEE IMAGE: