Messing with the carbs

[CrazyHorse]

Just experimenting with the carbs. I have a 1990 and installed the original 1983 42.5 pilot jets and 180 air jets. Idled nice a little more power, mileage about 36 mpg at 70 mph and 4000 rpm. Did what 5bikes described to improve mileage lowered needles power was decent and mileage improved to 40-43mpg at 70 mph @ 4000rpm. Just for fun I used the the original 1983 needles which have 5 positions to raise or lower the needles unlike the 1986+ needles which have no adjustments. The 1986+ taper of the needles is less then the 1983-85 needles. Took the 83 needles and raised them to the highest setting its got real nice power but its running rich I can smell it on my clothes, slight stumble on the initial throttle twist then its a rocket, mileage a grand high of 25 mpg. Im gonna now set it to the lowest needle setting (so it sits deeper) and see what results I get.

 

Anyone know if the the actual tube the needle sits in is different from 83-85 to 86-93?

 

Just playing around with this stuff.

[Yammer Dan]

iNTERESTING. gIVE US LOWEST AND HIGHEST WHEN YOU GET DONE.

[Dano]

Squeeze will tell ya when he gets on. He's in Germany so he's 6 hrs ahead of us.

 

Dan

[mbrood]

I don't know about the mechanical differences but the parts list shows whole differnt numbers:

1983 26H-14941-06-00 Nozzle, Main

26H-1490J-00-00 Needle Set

41R-14940-00-00 Diaphragm Assy

 

 

1986 26H-14941-90-00 Nozzle, Main

1NL-1490J-00-00 Needle Set

1FK-14940-00-00 Diaphragm Assy

 

The plastic slide for the XVZ1200 appears to be exactly the same except the bleed hole

is about 2/3 the size of the XVZ1300.

[CrazyHorse]

I don't know about the mechanical differences but the parts list shows whole differnt numbers:

1983 26H-14941-06-00 Nozzle, Main

26H-1490J-00-00 Needle Set

41R-14940-00-00 Diaphragm Assy

 

 

1986 26H-14941-90-00 Nozzle, Main

1NL-1490J-00-00 Needle Set

1FK-14940-00-00 Diaphragm Assy

 

The plastic slide for the XVZ1200 appears to be exactly the same except the bleed hole

is about 2/3 the size of the XVZ1300.

 

I figured this might be the case I'm wondering if the diameter of the nozzle is much different. I should mike the needles at the widest point and see what I come up with.

[Venturous Randy]

This is really good info. I usually get around 39 to 42 on my 83 and have been playing around with moving the needles out a little to see if it changes anything.

RandyA

[Squeeze]

As Mike stated, the Emulsion Tubes are different between MKI and MKII.

 

In Fact everything is different, what Mike listed above and the Springs aren't the same either. The MKI Springs are weaker to adjust the Difference in the Lifter Hole Boring.

 

There may not be any Difference in the Emulsion Tube Boring. I don't know for sure on the MKI/MKII, but it's possible that the Tubes are formed like Jets inside to create a second Venturi Effect.

 

I've seen such Emulsion Tubes at two or three Maxxes, but couldn't research it down to a specific Model, Year or anything else. All Bikes have been bought used, so nobody knows for sure where these came from.

[mbrood]

Thanks Squeeze. I didn't even think to check out the springs. I bought a diaphragm for an "86"... but it had the wrong lifter hole size (.09" / 2.28mm) and perfectly matched the 84 diaphragms lifter hole. The outer diameter is the same (1.178" / 29.93mm) and the inner diameter is a straight tube (.96" / 24.4mm) for the first .865" and then abruptly changes to a slightly smaller ID... maybe .945.

 

83 26H-14933-00-00 SPRING, DIAPHRAGM

86 1FK-14933-00-00 SPRING, DIAPHRAGM

 

and of course, with this "supposed" 86 diaphragm came a spring...

41R-14933-00 now I know what the guy was selling...

 

I received the slide and spring from an 84... yep, the 83 and 84/85 are different. Rather goes with the different jets in the later two years.

(Read below for corrected part numbers)

Edited November 7, 2008 by mbrood

[Squeeze]

Yes Mike, you got that right. I was mixing up the '83 Carbs with 'MKI Carbs. There ist the Difference in Lifter Hole Boring and Spring. Sorry for that Error.

 

 

So , there are three different Springs over the Years ??

 

83 is 26H-14933-00-00 SPRING, DIAPHRAGM

84 -85 is 41R-14933-00-00

86 -93 is 1FK-14933-00-00 SPRING, DIAPHRAGM (1Fk for Vmax)

[Squeeze]

... but it had the wrong lifter hole size (.09" / 2.28mm) and perfectly matched the 84 diaphragms lifter hole. The outer diameter is the same (1.178" / 29.93mm) and the inner diameter is a straight tube (.96" / 24.4mm) for the first .865" and then abruptly changes to a slightly smaller ID... maybe .945, ...

 

Now, another Thing would make Sense to me.

 

There was Posting from a Member about 4 Weeks ago, in which he reported he couldn't fit the Spring into the new Diaphragm he purchased. I ever wondered about this, because i couldn't think about such a Thing. It recurred several Times in Mind.

 

Now, with a "bigger" Diameter Spring and a smaller Diamter on the bottom of the Slider, the big Spring won't go into deep Place. Seems that Mystery is solved.

[mbrood]

I'll take a bit and try and see the differences... BUT the 83 shows THREE diaphragm numbers...

 

20	99999-01536-00	DIAPHRAGM ASSY (26H-14940-00-00)		1
20	41R-14940-00-00	DIAPHRAGM ASSY		1
20	41R-14933-00-00	SPRING, DIAPHRAGM

I KNOW the 41R-14933 SPRING fits inside the diaphragm that has a reduced ID part way down... don't know about the others.

How's a guy suppose to know what to order for an 83?

 

Here's the highlighted differences between 83 and 84... (I found a few typo errors for both the 83 AND 84 and with Squeezes help, this should be a corrected copy).

 

1983 Venture 1 26H-14900-00-00 CARBURETOR ASSYN/A1 2 26H-14901-00-00 CARBURETOR ASSY 1 1 3 26H-14902-00-00 CARBURETOR ASSY 2 1 4 26H-14903-00-00 CARBURETOR ASSY 3 1 5 26H-14904-00-00 CARBURETOR ASSY 4 1 6 98503-04014-00 SCREW, PAN HEAD (98580-04014-00) 3 7 26H-14958-00-00 COVER, DIAPHRAGM 3 8 98580-05012-00 SCREW, PAN HEAD (97801-05012-00) 8 9 93210-03119-00 O-RING 1 10 341-14991-00-00 SCREW 3 11 3G2-14231-16-00 JET, POWER (#080.0) 1 12 11H-1410A-00-00 STARTER SET 1 13 22U-14536-00-00 GASKET 1 14 2L1-14191-00-00 PLUG, DRAIN 1 15 241-14147-00-00 O-RING 1 16 3LD-1490H-00-00 DIAPHRAGM SET, 5 1 17 3G2-14231-36-00 JET, 1 MAIN (#180.0) 1 18 98511-04012-00 SCREW, PAN HEAD 4 19 92901-04600-00 WASHER, SPRING 192901-04100-00) 4 20 41R-14940-00-00 DIAPHRAGM ASSY 1 21 26H-1490J-00-00 NEEDLE SET 1 22 22U-14199-00 GASKET 1 23 22U-14147-00-00 O-RING 1 24 22V-14147-00-00 O-RING 1 25 26H-1411A-00-09 BLOCK JET ASSY 1 26 26H-14941-06-00 NOZZLE, MAIN 1 27 137-14153-00-00 WASHER, MAIN JET 1 28 22U-14565-00-00 SCREW 1 29 4G0-14142-42-A0 JET, PILOT (#42.5) (4G0-14142-42-00) 1 30 98503-04014-00 SCREW, PAN HEAD (98580-04014-00) 1 31 92901-04600-00 WASHER, SPRING (92901-04100-00) 1 32 26H-1414G-00-00 PIPE, MAIN BREED 1 33 26H-14985-00-00 FLOAT 1 34 22U-14190-15-00 NEEDLE VALVE ASSY 1 35 1J7-14994-00-00 NET, FILTER 1 36 41R-14933-00-00 SPRING, DIAPHRAGM 1 37 3G2-1423A-74-00 JET, MAIN (#370.0) (3G2-14231-74-00) 1 38 22U-14561-00-00 O-RING 1 39 22U-14115-00-00 PLUG, SCREW 1 40 22V-14968-00-00 CAP 1 41 22U-14968-00-00 CAP 1 42 26H-14952-00-00 WASHER 1 43 31H-14197-00-00 PIPE 2 44 26H-14197-00-00 PIPE 2 45 22U-1490M-00-00 STARTER LEVER SET, 2 4 46 26H-14193-00-00 PIPE 2 47 31H-14193-00-00 PIPE 2 48 92603-06010-00 SCREW, FLAT HEAD 1 49 31H-14987-00-00 HOSE 1 50 31H-14139-00-00 CLIP, PIPE 2 51 90467-10008-00 CLIP 5 52 26H-14987-00-00 HOSE 1 53 26H-1490L-00-00 STARTER LEVER SET, 1 1 54 26H-14504-00-00 ROD SET 1 55 98580-06010-00 SCREW, PAN HEAD 16 56 26H-14139-00-00 CLIP, PIPE 1 57 98580-05014-00 SCREW, PAN HEAD (97801-05014-00) 1 58 31M-14139-00-00 CLIP, PIPE 1 59 26H-26313-00-00 CABLE, THROTTLE 3 1 60 26H-2631J-00-00 CABLE, THROTTLE 4 1 61 41R-14118-00-00 CAP 1 (for float valve seat) 62 822-14147-00-00 O-RING (for float valve seat)

1984 Venture 1 41-V1490-00-00 CARBURETOR ASS''Y 1 2 41V-14901-00-00 CARBURETOR ASS''Y 1 1 3 41-V1490-20-00 CARBURETOR ASS''Y 2 1 4 41-V1490-30-00 CARBURETOR ASS''Y 3 1 5 41V-14904-00-00 CARBURETOR ASS''Y 4 1 6 98503-04014-00 SCREW, PAN HEAD 3 7 26-H1495-80-00 COVER, diaphragm 3 8 98580-05012-00 SCREW, PAN HEAD 8 9 93210-03119-00 O-RING 1 10 341-14991-00-00 SCREW 3 11 3G2-14231-16-00 JET, MAIN 80 (80) 1 12 11H-1410A-00-00 STARTER SET 1 13 22U-14536-00-00 GASKET 1 14 2L1-14191-00-00 PLUG, DRAIN 1 15 241-14147-00-00 O-RING 1 16 3LD-1490H-00-00 DIAPHRAGM SET, 5 (26H-1490H 1 17 3G2-14231-34-00 JET, PILOT AIR (170) 1 18 98511-04012-00 SCREW, PAN HEAD 4 19 92901-04600-00 WASHER, PLATE 4 20 41R-14940-00-00 DIAPHRAGM ASSEMBLY 1 21 26H-1490J-00-00 NEEDLE SET 1 22 22U-14199-00-00 GASKET 123 22U-14147-00-00 O-RING 1 24 22V-14147-00-00 O-RING 1 25 26H-1411A-00-09 BLOCK JET ASSY 1 26 26H-14941-06-00 NOZZLE, MAIN 1 27 137-14153-00-00 WASHER, MAIN JET 1 28 22U-14565-00-00 SCREW 1 29 4G0-14142-37-A0 JET, PILOT (37.5) 1 30 98511-04016-00 SCREW, PAN HEAD 1 31 92901-04600-00 WASHER, PLATE 1 32 26H-1414G-00-00 PIPE, MAIN BREED 1 33 26H-14985-00-00 FLOAT 1 34 22U-14190-15-00 NEEDLE VALVE ASSEMBLY 1 35 1J7-14994-00-00 NET, FILTER 1 36 41R-14933-00-00 SPRING, DIAPHRAGM 1 37 3G2-1423A-74-00 JET, MAIN (#117.5) 1 38 22U-14561-00-00 O-RING 1 39 22U-14115-00-00 PLUG, SCREW 1 40 22V-14968-00-00 CAP 1 41 22U-14968-00-00 CAP 1 42 26H-14952-00-00 WASHER 1 43 31-H1419-70-00 PIPE 2 44 26H-14197-00-00 PIPE 2 45 22U-1490M-00-00 STARTER LEVER SET, 2 4 46 26-H1419-30-00 PIPE 2 47 31-H1419-30-00 PIPE 2 48 92680-06010-00 SCREW, flat head (92603-06010 1 49 31H-14987-00-00 HOSE 1 50 31H-14139-00-00 CLIP, PIPE 2 missing 51 26H-14987-00-00 HOSE 1 52 26H-1490L-00-00 STARTER LEVER SET, 1 1 53 26H-14504-00-00 ROD SET 1 54 98580-06010-00 SCREW, PAN HEAD 16 55 26H-14139-00-00 CLIP, pipe 1 56 98580-05014-00 SCREW, PAN HEAD 1 57 31M-14139-00-00 CLIP, PIPE 1 58 41V-26313-00-00 CABLE, throttle 3 1 59 41V-2631J-00-00 CABLE, THROTTLE 4 missing missing

Edited November 7, 2008 by mbrood

[Squeeze]

I'll take a bit and try and see the differences... BUT the 83 shows THREE diaphragm numbers...

 

20	99999-01536-00	DIAPHRAGM ASSY (26H-14940-00-00)		1
20	41R-14940-00-00	DIAPHRAGM ASSY		1
20	41R-14933-00-00	SPRING, DIAPHRAGM

I KNOW the 41R-14933 SPRING fits inside the diaphragm that has a reduced ID part way down... don't know about the others.

How's a guy suppose to know what to order for an 83?

...

 

 

Mike, there are only two Diaphragms/Sliders listed. The '14940' indicates the same Parts, the first Three Digits are from the Model the Part first appeared. The Parts # 41R-14933-00-00 is the Spring itself. Only the describing Text is a bit misleading.

 

 

 

But you're right, there's no Way deciding what Part you'll need to order, because nowhere is a Number to find.

[mbrood]

Thanks Squeeze, I'll fix that. And now that it's so obvious... the second listing for the 83 - item#20 is CALLED a SPRING and is the EXACT part number for the 84-item 36... just a typo. So that leaves us with just ONE diaphragm for the 83/85 bikes... 41R-14940-00-00

but the springs are listed different (or its a typo) 83 = 26H-14933-00-00 84 = 41R-14933-00-00... So I did a look-up for pricing and the 26H number comes up dead... maybe we solved that too... the 83-85 spring, diaphragm and needle set are all the same. found a couple more typos for the 83 and 84 that don't work on a few part look-ups... so more and more are common... oddly the 84 throttle cables are cheaper.

I've edited the above listing to be (what I believe) is a corrct listing.

 

Just for added info (like we need that?), the 84 I can touch has the same "slider" as I descrbed above and the spring is the SAME O.D. (.91" / 23.11mm) and length (about 6.33" / 161mm?).

Edited November 7, 2008 by mbrood

[CrazyHorse]

Squeeze what effect does the air jet size have on performance. At least for my bike it seems the the 170 jet was better then the 180 jet.

[CrazyHorse]

Wow you guys come up with some ggod stuff.

[CrazyHorse]

My mileage of 25 mpg with this set up was also affected by more very generous throttle twists then my usual measuring standard of 70 mph @ 4000 rpm went a little higher then that. Its also fairly cold here which drops mpg also. I'll have to get some results with my standard test 100 mile round trip 70 mph@ 4000 rpm over a period of a few days.

[5bikes]

1. I rarely change the OEM's jet sizes, parts etc. They spent hundreds of hours tuning them close from idle to Full Throttle

2. I just try to modify their settings.

At cruising speeds: this effects overall mpg the most, if your under 40 do #3

3. To Lean: make the jet needle LONGER or extend further out of the black slide.

4. To Richen: make the needle shorter or extend further into the black slide.

At idle

5. To lean: turn the pilot screw IN (1/2 to 1 turn at a time)

6. To richen: turn the piolt screw OUT

Full throttle, if you must: (Almost never have to change this jet).

7. To lean: go down 5 to 10 points from the std. main jet

8. To richen go up 5-10 points from the std. main jet

 

To do # 3 look up posting "Improving Gas Mileage"

I did # 3 and 5 only to get to 49 mpg average. mostly at 65 mph. My friends '88 gets 46 mpg.

But if your heavy handed on the throttle at every acceleration, drive in the cold. drive 10-30 over the speed limit, drive into headwinds all the time, carry heavy loads your gas mileage will be less BUT not under 40 mpg.

Questions? PM me.

[Squeeze]

Squeeze what effect does the air jet size have on performance. At least for my bike it seems the the 170 jet was better then the 180 jet.

 

This Jet(PAJ#2) is sitting behind the Diaphragm and the Size effects the Moving of the Slider. The smaller this Jet is, the faster the Slider will react to changes in the Vaccum.

 

This will give you a faster Throttle Response and therefore it feels better and stronger. If you ride with a nervous Wrist, it can hurt your Mileage.

[Oldgold]

After many phone calls, e-mails and trips to two dealers it seems that the diaphragms they're showing for an 83 won't accept the original 83 springs, they're just a hair bigger than the later models, I found out that if you buy the diaphragm kit, they include the later springs which fit properly. The tech at the 1 dealer I went to was aware of the problem and was able to get me 4 used ones. Thanks to all for responses.

They don't sell the 83 diaphragms any more so you get the later version with the step and must use the later springs. I haven't been able to ride that much since the change so I don't have a real good feel for what it's done to mileage and my clutch is too weak for a real performance check.

[CrazyHorse]

I did # 3 and 5 only to get to 49 mpg average. mostly at 65 mph. My friends '88 gets 46 mpg.

But if your heavy handed on the throttle at every acceleration, drive in the cold. drive 10-30 over the speed limit, drive into headwinds all the time, carry heavy loads your gas mileage will be less BUT not under 40 mpg.

Questions? PM me.

 

My only question is how accurate is your speedo mine is off 8-10 mph at indicated 65mph in reality I'm only doing 55 mph. 49mpg seems hard to accomplish unless your driving 45 mph.

[Venturous Randy]

My only question is how accurate is your speedo mine is off 8-10 mph at indicated 65mph in reality I'm only doing 55 mph. 49mpg seems hard to accomplish unless your driving 45 mph.

 

If you are interested in resetting your speedometer on your 1st gen, let me know. I believe we can get to within 1 or 2 mph. I did mine and it is about perfect.

RandyA

[CrazyHorse]

If you are interested in resetting your speedometer on your 1st gen, let me know. I believe we can get to within 1 or 2 mph. I did mine and it is about perfect.

RandyA

 

Yes that would be great could you post it. Thanks