My Vmax performing like a 500cc

[Traumahawk]

Thanks Yep, looks familiar.
So that measurement (if not going by the circle edge on a circle) is from the float down... but see how the body is curved at that exact point? the inside corner is kinda curved, so how does one get an accurate measurement and consistent?. just a thought... how do you guys all do it? i'm sure everyeone else here has done this whole thing way more many times than myself.... do ya go the circle or do ya go with measurement?

Set for 1.125 inches to get a 17 mm wet level.

 

[radley]

Set for 1.125 inches to get a 17 mm wet level.

better pic, thanks! Let ya'll know how it goes tonight.

 

[[email protected]]

No need to reinstall carbs for a wet level check.

You can rig a Jerry can to the fuel inlet with the carbs on the bench. Set the carbs up level.

You can go as far as mimicking the fuel pump pressure like Dan-o but most mere mortals don't take it that far.[emoji1]

Sent from my SM-G930V using Tapatalk

 

[radley]

Good morning Vmaxers,

I will not be starting off this overcast a.m. with great news. Quite the contrary actually.

Broke the carb rack down to the 2 pairs. set on level surface, adjusted the float height, did the 1 1/8" approach. Put the float covers back on and pushed the carb pairs onto the bike with the boots. hooked up the gas line. put the throttle linkage onto the carb 3,4 pair so I can manually pull on throttle cable. The enrichner linkage was not hooked up. Of course the airbox isn't on and the carbs are not synced up. It was close last year when I tried to troubleshoot this issue, but the problem is beyond that small stuff.

So before I tried to start it, I wet tested the float level again.... and carbs 1 & 2 were a little rich, probably at 14mm. Carbs 3 & 4 were within spec and if I remember, closer to the leaner side, 16 & 17mm.

Was able to start the bike with manually pulling out enrichners to keep it running.....same issue as last year (after I did entire carb clean and replaced many parts, also all new fluids and plugs.)

So, here we go again, she won't run. its like it's starving for fuel but I know the pump is working, the bowls fill up when I turn the key, etc...

I can only get it to run with the choke engaged or enrichners out, however u wanna say it.

So now what... take the carbs apart one by one again and make sure all the jets are clear, for this to happen again? nah, I did that last year and the bike is running the same way.

It's a separate issue, and I have no idea what. I see the slides vibrating when I do get it running, all 4 slides are moving so I'm assuming that it's firing on all cylinders.... The slides don't move much of course at idle rpm's til I try to pull on that fuel line and give her some gas.... but the the bike bogs down and nearly dies - same as last year.

 

[Traumahawk]

So something is clogged, how did you clean the carb bodies? Did you soak them, use a sonic cleaner.....or how?

 

[fmcandrew]

Time to check the valves??? Do you know anybody with a Vmax close by that you could do a carb swap? I'd be curious how it runs with a known running set of carbs installed...

 

[radley]

I took the carbs apart piece by piece and cleaned them out, replaced several gaskets, orings and a few parts, jets etc after cleaning the metal parts with carb cleaner, pretty much scrub and rub a dub. At that time I was on here of course and someone mentioned an ultrasonic, so I bought one of them and used simple green to re-clean the parts.... this was before assembly. It didnt do much as most of the parts were already spin n span pretty much, we're talking an entire breakdown of carbs and re-assembly via a sticky on here someone sent me.

after all that, I threw carbs back in and the bike didnt change behaviors.

** good idea with finding an alternative Vmax carb rack. A neighbor a few blocks down had a Vmax parked in their driveway one day last summer... lol.... i dont know of anyone cllose by to help out personally, so we're talking an awkward conversation with stranger neighbors trying to track down the guy who had a Vmax parked there one day last summer... LOL.... good idea though and possiblly worth a shot.... woulid be good to know if its the carbs or not..... that would be one way.

 

[one2dmax]

Good morning Vmaxers,

adjusted the float height, did the 1 1/8" approach
Of course the airbox isn't on and the carbs are not synced up
probably at 14mm.

Are these statements accurate?
IF so,
1.125" is at the top of the tolerance.
Without airbox on it will simply bog when trying to give any sort of rapid throttle. Even with it on but no faux cover it won't ride correctly (but will rev)
14mm is WAY off

 

[radley]

Are these statements accurate?
IF so,
1.125" is at the top of the tolerance.
Without airbox on it will simply bog when trying to give any sort of rapid throttle. Even with it on but no faux cover it won't ride correctly (but will rev)
14mm is WAY off

Everyone says to go with 1 1/8" distance from float to inside of carb body, so I guess that's waht I tried to do. For some reason my measuring is yielding a richer setting when I wet tested it. I'm gonna try to obtain that 17mm (wet test results) for a leaner mix, as recommended on here I guess... The one carb wet test was at 14mm, and the range as stated by people on here is 15-17mm so I dont think 14mm is way off.

Anyways if I separate the metal piece (float level adjustment metal piece wahgtever it's called), then the float will be lower when the carb is right-side up, which will yield me a leaner mix because when the bowl fills with gas, the float will float up and push that needle up and close whatever passage it's there for.......? Is that right? I'm just thinking out loud here .....

Ok so I'll try my best to obtain that 17mm wet test result for all 4 carbs. Once that's done, I'll put the rest of the rack back together (as the carbs should be good to go) and throw it on the bike. I'll then put the airbox on and faux cover. ( can someone tell me why that matters? why does the faux cover matter at all? also why does the airbox matter on carb performance as well, like the bike will bog when throttled..why? I get the filter part of it, but how does the airbox affect things? just curious.

anyways I"ll do all that, I'll post a video and I doubt it'll change a thing but at least ya'll can have a look/listen.

 

[radley]

Sooooooooo, here we go, taking apart all the carbs, again. Good thing is there are lots of new parts, so far so good. Lemme just double check a few things here.
tHE jet that goes on the jet block is not the 150 or 160 correct?
The jet that goes under the slide/diaphragm cover is the 150 correct?
The other one goes where it fits i guess....this one i had trouble removing, actually it wouldn't fall out after unscrewing it til it wouldnt go no more, didnt have a wire or anything to pull it outta there, can still try if ya'll want me to, but should be good....?.

Most parts have been ultra sonic cleaned with the warm water option on.. ran it a ocuple of times. I did put the small diaphragm piece in there, even though it was super clean anyways, but when I took it out, it seemed to have expanded - doesn't fit in the grooves ya know - reaches outside of em a bit... so in took a pic of that so ya'll can see.... dont tell me I gotta buy a new one now, actually i dunno why i'm asking. cuz i'm not gonna.

Ok well this is only carb #1, doin em one at a time.

I'll spray carb cleaner and air through all holes in the carb body before reassembly .

of course pulled the jets out of the jet block - the super small hole one may have been clogged up, hard to tell but should be good now. checked, installed it in jet block, decided to pull it out and check again, it was good. new rubber stoppers from parts purchase in fall as well as many others.... blah blah..

the needle/slide'/diaphragm part... how do u want this assembled? tell me exactly how/where ya'll want all those parts - i wanna put this back together to ya'll's standard so when my bike is still a POS non-runner, the carbs are out of the question as to what's wrong.

Also how many turns out A/F screw? dont worry, i got the oring, washer, spring, screw - bought all these brand new in the fall - damn right should be in good shape.

best part is that this is getting easier - know where all the parts go without having to divide up and label, etc... so that's cool.

 

[Traumahawk]

The main fuel jet should be 150 (mikuni).....the jet that is under the slide diaphragm (PAJ#2) SHOULD be 170 (Mikuni). It looks like someone had put a stage 1 jet kit in there (from looking at the needles)....so, you can keep the needles, but remove the small washer that it UNDER the clip. That small washer is there to give you a small amount of space under the clip (also known as a 1/2 clip washer).

How long are the springs that are between the slides and the covers? Stock is 7 inches, the stage 1/stage 7 springs are I believe 5 inches and are way softer.

 

[Traumahawk]

Mikuni jets will have MK on the and dynojet jets have DJ on them. Here's also how you can tell the difference as per Vmax outlaw. Mikuni jets are chamfered on the inside opening at the threaded end and
Dynojets have a machined flat surface.

 

[radley]

The main fuel jet should be 150 (mikuni).....the jet that is under the slide diaphragm (PAJ#2) SHOULD be 170 (Mikuni). It looks like someone had put a stage 1 jet kit in there (from looking at the needles)....so, you can keep the needles, but remove the small washer that it UNDER the clip. That small washer is there to give you a small amount of space under the clip (also known as a 1/2 clip washer).

How long are the springs that are between the slides and the covers? Stock is 7 inches, the stage 1/stage 7 springs are I believe 5 inches and are way softer.

Alright, thanks Trauama. I'll keep that table on file. You're right, when i had carbs rebuilt by someone else (never happening again) he did put in stage 1. the springs from diaphragm cover are 7" I think, so that's wrong, ****... maybe they're 5, i'll confirm after work i suppose.

As for the needle, where do you want that clip? I can move it. I was told by someone on here months ago to put it where it is, have it set up that way but I'll change it to whatever you guys want, let me know now while I'm in there before I re-assemble this first one tonight. also how many turns out for the A/F..., thnx

 

[Traumahawk]

Alright, thanks Trauama. I'll keep that table on file. You're right, when i had carbs rebuilt by someone else (never happening again) he did put in stage 1. the springs from diaphragm cover are 7" I think, so that's wrong, ****... maybe they're 5, i'll confirm after work i suppose.

As for the needle, where do you want that clip? I can move it. I was told by someone on here months ago to put it where it is, have it set up that way but I'll change it to whatever you guys want, let me know now while I'm in there before I re-assemble this first one tonight. also how many turns out for the A/F..., thnx

Keep the clip where it is, just remove the little washer that is between the clip and the donut.

Start with 2.5 turns all the way around. Every Vmax is different, so you will have to adjust accordingly.

Stock springs are 7 inches, and like I said I believe the stage 1/stage 7 springs are 5. What the softer springs do, is to allow the slide and needle to react quicker....IE pull the needle out, and there fore run RICHER.

The downside to the complete stage 1 kit, is that you change the main jets and go richer. You change the needles, and go richer. You change the PAJ#2 jet, make it smaller, and so there is LESS air into the carbs...slides....etc.....therefore.....you run RICHER.

So, as far as tuning here is my recommendations.

PAJ#1 (jet on the top of the carbs) 90 mikuni (stock)
PAJ#2 (jet under the slide diaphragms) 170 mikuni (stock)
Main fuel jet 150 mikuni (or the DJ 160, which is equal to the 150's which will save on cost.)
Needles (If you keep the stage 1 needles, 1st clip from the blunt end) or stock needles......but keeping the stage 1 needles will keep cost down, and with the right main jet, they do run decently.
Springs 7 inches......stock

 

[Jan Bee]

Sooooooooo, here we go, taking apart all the carbs, again. Good thing is there are lots of new parts, so far so good. Lemme just double check a few things here.
tHE jet that goes on the jet block is not the 150 or 160 correct?
The jet that goes under the slide/diaphragm cover is the 150 correct?
The other one goes where it fits i guess....this one i had trouble removing, actually it wouldn't fall out after unscrewing it til it wouldnt go no more, didnt have a wire or anything to pull it outta there, can still try if ya'll want me to, but should be good....?.

Most parts have been ultra sonic cleaned with the warm water option on.. ran it a ocuple of times. I did put the small diaphragm piece in there, even though it was super clean anyways, but when I took it out, it seemed to have expanded - doesn't fit in the grooves ya know - reaches outside of em a bit... so in took a pic of that so ya'll can see.... dont tell me I gotta buy a new one now, actually i dunno why i'm asking. cuz i'm not gonna.

Ok well this is only carb #1, doin em one at a time.

I'll spray carb cleaner and air through all holes in the carb body before reassembly .

of course pulled the jets out of the jet block - the super small hole one may have been clogged up, hard to tell but should be good now. checked, installed it in jet block, decided to pull it out and check again, it was good. new rubber stoppers from parts purchase in fall as well as many others.... blah blah..

the needle/slide'/diaphragm part... how do u want this assembled? tell me exactly how/where ya'll want all those parts - i wanna put this back together to ya'll's standard so when my bike is still a POS non-runner, the carbs are out of the question as to what's wrong.

Also how many turns out A/F screw? dont worry, i got the oring, washer, spring, screw - bought all these brand new in the fall - damn right should be in good shape.

best part is that this is getting easier - know where all the parts go without having to divide up and label, etc... so that's cool.

The jet that goes on the jetblock (main jet) should be the 150----the one under the jet that goes under the diaphragm is 90 or 100 if california model--the air jet you are looking at when you remove the airbox is 170. The super small hole being clogged is the most common problem on these carbs-be positive they are clean--Put the clip on the 2nd slot from the top of the needle with the 1/2step washer below the clip.then assemble just as you have it layed out in the last photo----2 1/2 turns out on all a/f mixture screws.

 

[caseyjones955]

Ill tell ya the part that I know. The diaphragm is expanded and it is reversible. Its saturated with solvent. I have read that there is the sitting them under the sun or an oven method but check for specifics. The needle should have the little Jesus clip on it at the blunt end, the white nylon needle spacer slides over the sharp end and slides up against that clip. It might be stiff so make sure its all the way against the clip. The little tiny tit faces away from the clip, towards the sharp end. Drop the needle/spacer through the center hole in the end of the slide, then that little silver washer goes in and rests on top of that Jesus clip, then the spring on top of that, then that nylon screw. I start the screw a turn or soo then push the needle inward against that spring pressure, then as I twist I can feel that little tit on the needle spacer fall into a hole for it. Then Im satisfied it has seated I snug up that nylon screw, and barely snug. Resist the urge to reef that down, once they are all done just compare them to make surr the needles are all the same length from the end of the slide, its an extra OCD check I do just to make sure I have it right. Be mindful of keeping each slide with the specific carb it was taken from.

The main jet is the one in the jet block that sits under the bowl plug, its the one you can change through that hope without taking the carbs apart. It probably is 150 or 160 and my guess is it could stand too be a touch smaller but someone else can double check your jet size and the clip position on the needle for a good starting point. Some needles only have one place for the clip, and others have 5 possible clip positions. When you are playing with jets do remember that jet sizes for MK and DJ are not the same. Factory is MK 152.5, im running a 147.5. Your altitude and bikes setup are factors that determine appropriate jet and needle settings but generally they are a little rich from factory. Did you bench set float levels? Those are usually a tad rich from factory too. There is a sticky here for that but I cant link on the phone.

When I put carbs on and do an initial dial in I put the Carbtune synch tool on before I even start it and begin with the AF screws 2.5 out. Once the bike has warmed up I synch, then set AF screws by ear since I have no CO2 meter. Then once its all done I make sure the synch is as spot on as I can get it. Then check AF screws again, its redundant but when I'm done its as good as I can possibly make it. While I he bike is running if you look into the carbs and give it some revs all the slides should react the same. If any are lazy or binding up that will have too be addressed. With engine off the slides should push back by finger and take about a second to snap forward again, no binding should be felt. Also the bike might run like **** if the filter and lid are off so when I tune and synch I make sure filter and lid are all installed.

That jet under the he diaphragm is (double check me on this) PAJ#2 and a 150, again check me on that. Some jet kits have a different size to make ot richer, mine did and it was a very bad thing, much better when I went back to stock on that jet. It is an air jet, not a fuel jet like the mains so smaller numbers are richer, unlike the mains where smaller are leaner.

If I got anything wrong here I'm sure ill be corrected. Good luck

Edit, you good good guidance while I was typing haha.

 

[Jan Bee]

The jet that goes on the jetblock (main jet) should be the 150----the one under the jet that goes under the diaphragm is 90 or 100 if california model--the air jet you are looking at when you remove the airbox is 170. The super small hole being clogged is the most common problem on these carbs-be positive they are clean--Put the clip on the 2nd slot from the top of the needle with the 1/2step washer below the clip.then assemble just as you have it layed out in the last photo----2 1/2 turns out on all a/f mixture screws.

My mistake Radley-170 under the diaphragm and either 90 or 100 under the airbox--those do look like canadian needles which are set by the factory on the 3rd notch.I would suggest the 2nd notch with the 1/2 step washer underneath for a little leaner than stock.

 

[radley]

how do i get that 160 out of there? lefty loosey, and it's not caught int he threads, but it's just too tight in there. may never have been out since install long time ago when the dude put in the stage 1 kit. could try pushing air through but assume that won't work.... i had no idea about any of this stuff at the time, so Like Trauma said.... work with what i got and maybe have to pick up some 170s.... either that or i'll be running the 160s.

Casey, have not since bench wet tested yet, gonna have to wait til reassembly of course and getting correc t jets.. sounds like all i gotta get is those 170s?

there seems to be some discrepancy with where to put the clip on the needle.... do I flip a coin or waht...

 

[Traumahawk]

Well that jet definitely needs to come out, especially if its a 160 in PAJ#1. Right there should be a 90.

Here is some carb theory to help it to sink in about PAJ#1. It helps control the amount of air coming into the carb at idle. It affects the A/F ratio at idle. So, having too big of a PAJ#1, will allow too much air into the carbs, and make it difficult to set the idle.

PAJ#2 controls the amount of air coming into the carb JUST off idle. So, if PAJ#2 is too small, it will cut off the amount of air coming into the carb just off idle, all the way to redline. So, if PAJ#2 is too small.....again, making you run rich.

Hopefully others will chime in, on the best way to help get that jet out. Me personally I would think about taking it to a machine shop.

On the needles, its your choice. I played with a stage 1 kit, when I was dynoing a LOT about 2-3 years ago. I made decent hp on the dyno with 150 mains, and the stage 1 needles 1st clip from the blunt end. I am also about 1100 ft elevation.

Canadian needles are like stock needles, but are adjustable. Stage 1 needles are more aggressive than stock, or canadian needles.

 

[caseyjones955]

I dry set them on the bench during assembly according to this.
http://www.factorypro.com/Prod_Pages/prody11.html

You can wet test them after assy.