same old jetting questions :(

[vmaxinID]

Ok, Ok, here it goes

I have installed a HMF 4-2 "2D9S" full system into my 2WF engine.
I have had to swap out the 2WF Carb due to two of the Idle mixture screws being totaly FUBAR.
It is being replaced with a 49 state Carb with Stage 1 needles and stock jetting;
152.5 mains, PAJ#1 90, PAJ#2 170
Uni foam filter

So, Should I stay stock? Elevation 4,500 feet.
and can I get a ballpark on the jet needle clip setting.
Referenced from the top notch i.e. 1st notch, 2nd notch, 3rd notch from the non needle "top"

This summer I will be upgrading to a Morley muscle kit so I may be adjusting later.

P.S. It used to have Cobra 4-4 when I bought her so it's been quite rich for a while. The exhaust stunk like gas so bad during the teardown, PHEW!

 

[shawn kloker]

All the carbs have the same jets and needles now right?Not just the new 2.I would start with the 3rd clip from the top in colder weather then 2nd after it warms up.150mk mains should work fine at your elevation maybe even 147.5's.It all depends on how things go.How does it run?How do the plugs look.Are the valves adjusted?Carbs synced real good?No air leaks in any of the boots?Is the vboost cable slack adjusted out?Are the float levels correct?There are many variables that effect performance.Dyno time is a good tuning aid,never hurts to see what she'll pull on horse power too.

 

[vmaxinID]

All carbs, same jetting and needles.
I am about to put on the carbs so need an opinion on what mains to put on for 4500 ft. elevation. 150mk mains? (paj1, paj2 stock?)
The old plugs look like total shit, black as hell (cobras!)
No adjustments done to valves 13,000 on motor.
I sync my own carbs, and will when they go in this week.
I replaced all rubber boots.
Vboost cable checked, no slack.
Floats good, fabricated tank and float check.

3rd clip cold, 2nd clip warm, got it

Who is a good person to buy mk Mains from? I would like 4 150's, and 4 147.5's. I do beleive.

 

[maleko89]

You should probably be able to accept WOT in any gear above 2K w/o any bucking or complaint.

Do the following tests.

1) Cruise at 4K in 5th gear .. hold RPM steady (count to 5) and then whack it WOT as quickly as you can. You shouldn't feel the slightest delay or hesitation. If you do, too rich. This does not work at 3.5K or 4.5K, only at 4K because the slides will start to retract at 4.5K even at the lightest throttle angle. 4K sets us up on the threshold and gives us a big jump when we whack it. there is no other RPM to do this where you will get as big a slide jump when rapidly moving to WOT.
This tests for too rich of needle.

2) Verify that starting cold .. that the engine is weak .. and will complain if you try to hold the RPM at 1800 rpms. Within 1-2 min or no later than when the temp needle touches the first mark you should be able to hold the engine between 1500 and 2K w/o complaint or popping back through the carbs. At the least you should be able to do this by the time the engine is fully warmed up but if you are more than 1/2 way between the dot and cold on the temp gauge your pilots are plugged or too lean... (clean or reduce the PAJ2). If you can hold 1.5-2K as soon as you start cold then your pilots are set too rich and you will suffer rich symptoms when it comes to operating temp (clean or enlarge the PAJ2). ONly change PAJ2 bigger/smaller if you mixture screws are out or in too far already.
This is how you set your pilot mixture.

3) Do a hard WOT pull in 2nd or 3rd gear from below 3K. Look for a smooth pull all the way up. If it seems to lag in the 4-5K range then too much needle. If we sputter going past 4.5K you don't have enough needle.
This tests for needle richness and leaness.

4) Verify you can cruise "nice and deliberate" at 5K .. if you stumble around and are OK everywhere else you don't have enough pilot.
Another pilot mixture test.

As for your mains, I'd at least go to 147.5's. General rule is to subtract main jet size by 1% for every 1000 feet above sea level. So, need to decrease main jet size of 152.5 by 4.5%. 95.5% times 152.5 = 145.6. I'm thinking 145's would work best at 4500 feet above sea level.

 

[shawn kloker]

All carbs, same jetting and needles.
I am about to put on the carbs so need an opinion on what mains to put on for 4500 ft. elevation. 150mk mains? (paj1, paj2 stock?)
The old plugs look like total shit, black as hell (cobras!)
No adjustments done to valves 13,000 on motor.
I sync my own carbs, and will when they go in this week.
I replaced all rubber boots.
Vboost cable checked, no slack.
Floats good, fabricated tank and float check.

3rd clip cold, 2nd clip warm, got it

Who is a good person to buy mk Mains from? I would like 4 150's, and 4 147.5's. I do beleive.

Parts unlimited has them in sets of 4 for $2.50,$1.50 with our discount at university motors.Look at www.partsunlimited.com then go to the street catalog.I just ordered tonight some 160,165,175,185 &190 mains.
KN102221160
KN102221165 etc.etc. $1.50/4 is the screaming deal of the century.$2.50 per jet was the best price I found before these.Most places were up to $5 each,Come on!And these are mikuni.

 

[shawn kloker]

You should probably be able to accept WOT in any gear above 2K w/o any bucking or complaint.

Do the following tests.

1) Cruise at 4K in 5th gear .. hold RPM steady (count to 5) and then whack it WOT as quickly as you can. You shouldn't feel the slightest delay or hesitation. If you do, too rich. This does not work at 3.5K or 4.5K, only at 4K because the slides will start to retract at 4.5K even at the lightest throttle angle. 4K sets us up on the threshold and gives us a big jump when we whack it. there is no other RPM to do this where you will get as big a slide jump when rapidly moving to WOT.
This tests for too rich of needle.

2) Verify that starting cold .. that the engine is weak .. and will complain if you try to hold the RPM at 1800 rpms. Within 1-2 min or no later than when the temp needle touches the first mark you should be able to hold the engine between 1500 and 2K w/o complaint or popping back through the carbs. At the least you should be able to do this by the time the engine is fully warmed up but if you are more than 1/2 way between the dot and cold on the temp gauge your pilots are plugged or too lean... (clean or reduce the PAJ2). If you can hold 1.5-2K as soon as you start cold then your pilots are set too rich and you will suffer rich symptoms when it comes to operating temp (clean or enlarge the PAJ2). ONly change PAJ2 bigger/smaller if you mixture screws are out or in too far already.
This is how you set your pilot mixture.

3) Do a hard WOT pull in 2nd or 3rd gear from below 3K. Look for a smooth pull all the way up. If it seems to lag in the 4-5K range then too much needle. If we sputter going past 4.5K you don't have enough needle.
This tests for needle richness and leaness.

4) Verify you can cruise "nice and deliberate" at 5K .. if you stumble around and are OK everywhere else you don't have enough pilot.
Another pilot mixture test.

As for your mains, I'd at least go to 147.5's. General rule is to subtract main jet size by 1% for every 1000 feet above sea level. So, need to decrease main jet size of 152.5 by 4.5%. 95.5% times 152.5 = 145.6. I'm thinking 145's would work best at 4500 feet above sea level.

The test for the right main jet is to go out on a stretch of highway and hone the shit out of it.I like to stop then bang it up through all the gears shifting at 9500rpms wide open throttle the whole time.See how it pulls running only on the mains.To accurately read the plugs they should be pulled right after doing this,not after cruzing around town or all the way back home.

 

[vmaxinID]

Thanks for the heads up on jets, talk about low prices. I'll get what I might need and the others around it for that price.

Here in Idaho we have 75 mph Interstates so I am anxiously awating the "Main Jet" test.

So pull over after the "test" let her cool a bit then pull plugs.

Use new plugs and check for rich? i.e. liquid fuel residue?

What if she's lean when I test? Will it I F**k my motor up lightin' her up like that?

Since the "Spud Max" is tore down a bit is there any harm in polishing the inside of the intake manifolds?

We only have one Dyno in the area........at the Harley shop. It's $20 a pull
When I think she's close I'm gonna go down and raise some hell at the Dyno. They refuse to help in any adjustments, they are "unfamiliar" with the V4's.

 

[shawn kloker]

You do not want to polish anything on the intake side.The fuel with puddle up on it. $20 a pull is a steal.Too lean will make it pop and would have to be extremely lean for extended periods to melt a piston.Reading the plugs correctly is a science. Main jet size is also supposed to be the first thing(test)to do before the needle adjustment and so on. Factory pro has some good instructions for doing all this on their website.

 

[Rusty McNeil]

Thanks for the heads up on jets, talk about low prices. I'll get what I might need and the others around it for that price.

Here in Idaho we have 75 mph Interstates so I am anxiously awating the "Main Jet" test.

So pull over after the "test" let her cool a bit then pull plugs.

Use new plugs and check for rich? i.e. liquid fuel residue?

What if she's lean when I test? Will it I F**k my motor up lightin' her up like that?

Since the "Spud Max" is tore down a bit is there any harm in polishing the inside of the intake manifolds?

We only have one Dyno in the area........at the Harley shop. It's $20 a pull
When I think she's close I'm gonna go down and raise some hell at the Dyno. They refuse to help in any adjustments, they are "unfamiliar" with the V4's.

I "think" conventenial wisdom these days is that a polished surface inside of manifolds and heads takes away instead of contributing to the a/f mixtures ability to remain in a mist state. Polished surfaces reduce turbulence and aid in droplet formation. The natural casting surface I believe is beneficial.

Somebody more knowledgable like one of the two seans/shawns may have a better answer...

 

[vmaxinID]

Ok, Ok,

So I used the parts unlimited catalog for my mains.
KN102221145.
When I go to put them in they are the huge jets that i have to take off the whole damn float cover?
Where are the smaller ones I can just put in and take out with out disassembling the float?

 

[maleko89]

The main jets can be accessed by removing the hex nut on the float bowl covers. Loosen carefully and then use a toothpick to remove through hole in cover. Don't drop it, otherwise you must break open the float bowls.

 

[vmaxinID]

"So I used the parts unlimited catalog for my mains.
KN102221145.
When I go to put them in they are the huge jets that i have to take off the whole damn float cover?
Where are the smaller ones I can just put in and take out with out disassembling the float?"


I got the old mains out but tha new ones are too big to fit in the hole? The thread size and pitch is right but the head on it is too big?

Where Do I find the right Main jets to put in without having to remove float cover?

Thanks everybody.

 

[shawn kloker]

I guess I'll be screwed to.Those are supposed to be the small jets.SORRY!

"So I used the parts unlimited catalog for my mains.
KN102221145.
When I go to put them in they are the huge jets that i have to take off the whole damn float cover?
Where are the smaller ones I can just put in and take out with out disassembling the float?"


I got the old mains out but tha new ones are too big to fit in the hole? The thread size and pitch is right but the head on it is too big?

Where Do I find the right Main jets to put in without having to remove float cover?

Thanks everybody.

 

[shawn kloker]

I just looked again.Those should have been the small jets not the big head ones.I wonder if their was an error on their end at P/U?

 

[vmaxinID]

Well I had the Yamaha stealership get em outta the back, so dollars to donutz says it's their F-up. I'll go by tomorow and kick em in the ding ding.

Once again, thank you for your support.

 

[vmaxinID]

no more jetting questions

No more spittin', she's purrin' like a kitten!!!

No more poppin', and I ain't stoppin!!

Looks like I'm all aces for the season. :th_image003:

I think I am getting a crush on my second gear. :th_529:


A special shout out to maleko89 , shawn kloker, and Paul for all of their advice.

Now if you'd excuse me I have to stop by the ER room to have my shoulders put back in their sockets!!!! :stretche:

P.S. I took the GF for a spin, i think she peed a little.
Ah yes! Vboost.......... inducing accidential urine discharge since 1985.

 

[Rusty McNeil]

"P.S. I took the GF for a spin, i think she peed a little.
Ah yes! Vboost.......... inducing accidential urine discharge since 1985."


That's hilarious!!

 

[shawn kloker]

Better get a sissy bar for her if you already do not have one.Its real easy to loose a passenger on a vmax. I am finally getting to start my bike today.I have not received my new jets yet and will have to just try some that I already have.The weather here sucks right now can't even go for a test ride.I am dying to hear it.Oil,water and battery hook up then break in the new cams.I'll post some pics later.

 

[vmaxinID]

Ok, Ok,

Bike runs great, Idle good no rise or fall, sync double checked, good rubber boots.

I'm getting a slight hang up (float, rise) at 3,000rpm when I blip the throttle only at 3,000 and nowhere else.
I checked the throttle cables and I don't feel any binding: flick, flick= click, click.

Is this a needle setting or something else.

It is very subtle almost not worth mentioning but it's there.

 

[maleko89]

You can either put a smaller size of PAJ2 in....say 167.5's or you can turn the mixture screws out a bit further.