marks pipes 4 into2 jetting fuel mileage question

[vmaxrooky]

I just bought a 1998 VMAX with Marks 4 into 2 pipes spark plugs seem a little rich does anyone know what the jetting should be? I'm at sea level maybe a 100-200 above it in California. I'm only getting 22MPG that seems a lot low to me for a bike and the last cruise I did I made sure I kept it out of the V-boost and same mileage.. Has k&n filters also stock tires front and rear also? Main jets and idle jets I read the air screws should be 3-3 1/2 turns out not sure if this would be the same for my set-up though?

 

[06VMAXIMUS]

So it has filter(S)? Individual filters means it probably has a stage 7 kit in it. Either way, you should be getting way better than 22 mpg.

 

[tothemax93]

I got this out of the carb section. It might help give you an idea. Do you know what you have now. http://www.vmaxforum.net/showthread.php?t=16981

 

[vmaxrooky]

no sorry it has K&N just one replacement filter a stock replacement on not 4 individual ones sorry about that...ill check that link out right now tothemax93 thanks

 

[vmaxrooky]

dam I would love the bike more if she got 26-39MPG i wish and what is paj2 and pag2?

 

[[email protected]]

PAJ is Pilot Air Jet.

Sounds like your bike is stock with Marks exhaust and a drop in KN filter.

Most guys end up dropping 1 or 2 sizes on the main with aftermarket exhaust if they are not running a jet kit although, Danny had respectable dyno numbers with the stock mains.

A/F screws can end up anywhere but 2-2.5 turns out is the norm.

Stock PAJ's should be fine.

Most need to shim the stock needles a touch with an aftermarket exhaust.

With mileage that bad I would be checking to make sure your are firing on all 4. Then I would pull the rack, clean, set the floats, and try the settings mentioned above.

My mileage varies wildly depending on how I ride. I may only 30 MPG zooming around the back roads at home. If I hit the highway I can see 40 MPG with no problem

 

[vmaxrooky]

ok i have experience with jetting two stroke banshees.. Banshee needles has 5 notches on it and a clip locks it to certain spots you can go up or down on a stock needle. is that what you mean by shim the needle? second what is the stock main jet in a vmax and the stock paj and I know what paj is now what does paj 1 paj 2? you said dropping the jets you mean going down or making them bigger? Going down I assume means say you have a 160 main going down i assume would be 158 155 and so on..but I recall when you add air and pipes you go up add more fuel? Hence your main was 160 so to add more fuel you would put in a 162 or a 165 main jet.. So you match the added air and added exhaust flow. so I'm a lil confused?

 

[KJShover]

your going to probably want to drop down a size. You have good elevation down there at 92'
I'm running 150's with my Morley kit at 440' up here.



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[[email protected]]

Stock main is 152.5
You are probably gonna want 150. I know, its opposite of what you are thinking.

http://vmax.lvlhead.com/tips/shotgun.htm
Check this link. It shows the locatations of PAJ 1 and 2. There is a thread in the carb stickies that talks about PAJ2 operation.

Stock Jet Sizes:
Main: Mikuni 152.5 (jet on top of jetblock)
Pilot fuel: Mikuni 37.5 (in jet block)
PAJ2: Mikuni 170 (behind slide diaphragm)
PAJ1: Mikuni 90 (top of carb next to main air jet)

 

[vmaxrooky]

thanks mike that give me a lil info she runs like a bat out of hell with the clutch slipping.. Still waitng for my clutch to come in and my fork springs also.. I'm gunna put new plugs in her this weekend and see what jets she has in her.. I love the power and its enough for me to be happy with just want a lil more MPG's....Can you chop check the plugs on a VMAX? Chop testing is going threw all the gears as fast as you can then pull the clutch in and shut the motor off.. My last bike was a CBR929RR so no I'm not afraid to go fast..

 

[dannymax]

Plug chop...4th gear @ 4k, whack it to red line, pull in the clutch and hit the kill switch.

Is the K&N filter clean?

Think a carb cleaning, float adjust & sync is needed before making changes, that way you know exactly what you have for springs, needles, jets, shims, etc. and go from there.

Wouldn't be a bad idea to check the valve lash either.

 

[KJShover]

....Can you chop check the plugs on a VMAX? Chop testing is going threw all the gears as fast as you can then pull the clutch in and shut the motor off.. My last bike was a CBR929RR so no I'm not afraid to go fast..

you can chop

 

[vmaxrooky]

Thanks checked the plugs last night on the shifter side front plug looked lean and the back plug looks perfect?

 

[vmaxrooky]

that was after a regular cruise out last night didn't chop the bike just rolled down to sonic last night came home and checked the plugs...

 

[Rand-5107]

What part of town are you in? I'm over by carpenter and woodland.

 

[06VMAXIMUS]

Best bet is the setup I got from Dannymax: Make sure float levels are set correctly, .038-.040 shim under the needles, and mixture screws out 2&3/4 to 3 turns. Ran great!!!

 

[vmaxrooky]

i live in turlock,ca I was born in modesto,ca

 

[vmaxrooky]

Ok got some info so you all aren't trying to help me blind lol... The jets on the side are 170 the needle has 5 settings on it and it is on the middle with a lil washer(shim) on top and a plastic washer thing on bottom and the jets under the factory air box are 100.... The main jets I didn't get to.. Going riding Saturday hopes his helps a lil.. When I'm in like 2nd or 3rd just putting around at like 3000-4000 rpm's it sounds like its loading up like a top fuel car at idle then roll the throttle and it takes a 1/10 of a second or so then wham it's on... Plugs look pretty good see pic I posted... All carbs leak fuel when I loosen the drain screws?? Haven't sync'd em yet?