Jet/needle I.D.

[tome36]

First off, I am new to the forum. I have used the search query but nothing exactly what I am needing. I recently bought a 2001 VMAX and while it runs strong all the way through top end it seems very rich. While checking valve lash I am in the process of rebuilding the carbs. Noticed the main jet is stamped 170. This must be a dynoget number as a mikuni should be much smaller. It is obvious some one has performed mods to this before so my question is how do I id if I have aftermarket needles, springs, etc in addition to the obvious changed main jetting. The pilot, PAJ1, PAJ2 are all stock according to the numbers. My biggest fear is if I go to 150 mains with a dynojet needle arrangement. Any help would be greatly appreciated before I start just buying stock parts again.

 

[tome36]

Update, Murphy's law hit again. Upon further searching I found a pic showing an assortment of needles, where it looks like I have the crappy dynajet stage 1 installed, especially since the main jets are stamped 170. The bike runs strong just slightly rich on the top end so I hope simply dropping the needles 1 position may help. Anyone who has been here before please chime in. I hate to spend money I don't have to. It does have a supertrap 4-1 open comp exhaust and KN air filter (which from past experience I'm not a big fan). I have had good luck with the supertrap exhaust though.

 

[Donny Daughtry]

Update, Murphy's law hit again. Upon further searching I found a pic showing an assortment of needles, where it looks like I have the crappy dynajet stage 1 installed, especially since the main jets are stamped 170. The bike runs strong just slightly rich on the top end so I hope simply dropping the needles 1 position may help. Anyone who has been here before please chime in. I hate to spend money I don't have to. It does have a supertrap 4-1 open comp exhaust and KN air filter (which from past experience I'm not a big fan). I have had good luck with the supertrap exhaust though.

When you say dropping the needle i'm sure you mean raising the clip a notch towards the blunt end to lean.

http://vmaxoutlaw.com/tech/dyno-mikuni.htm

 

[Traumahawk]

When you say dropping the needle i'm sure you mean raising the clip a notch towards the blunt end to lean.

http://vmaxoutlaw.com/tech/dyno-mikuni.htm

The 170 DJ is WAY too rich. As you can see on the link that was posted , it is equal to the MK (mikuni) 160. The 152.5 is the stock size jet. Thats why it is too rich uptop. going leaner on the needle will help, but only on the midrange.....not on the topend.

I would swap to the to a 150 main jet. Put the needle 1st clip from the blunt end. Also check out PAJ#2 (which are air jets that are under the diaphragm cover) they have probably been changed out from stock......so check and see if they are a 170 Mikuni, and if they arent.....put them back to stock.

Jets really arent that expensive. You can order from several places, but I would suggest Sean Morley, who is a supported of this forum. best way to get him is [email protected]

 

[tome36]

Yes, exactly. Turns out after research it does have the dynojet stage 1 kit installed. Slide are drilled with the bit that was supplied in the kit, 170 DJ mains, and the crappy stage 1 needles and springs. I moved it up from 3 to 2nd slot so we'll see how that does. For all the bad I've heard about the stage 1 kit it sure runs smooth and strong off idle through redline. When V boost kicks in at 6500 holy crap! Only complaint is when I was behind it with my buddy riding it it blows black smoke and the exhaust is coated in black soot. Just want to lean it up slightly.

 

[Nubicon]

Yes, exactly. Turns out after research it does have the dynojet stage 1 kit installed. Slide are drilled with the bit that was supplied in the kit, 170 DJ mains, and the crappy stage 1 needles and springs. I moved it up from 3 to 2nd slot so we'll see how that does. For all the bad I've heard about the stage 1 kit it sure runs smooth and strong off idle through redline. When V boost kicks in at 6500 holy crap! Only complaint is when I was behind it with my buddy riding it it blows black smoke and the exhaust is coated in black soot. Just want to lean it up slightly.

Just wait until you get that thing leaned out :rofl_200:

 

[tome36]

Thanks for the recommendations.

 

[caseyjones955]

Just wait until you get that thing leaned out :rofl_200:

+1

I had the same fight you have. I had it running ok with the stage 1 needle. I'm at altitude so running 147.5 main jets, stage 7 needles and the rest of the jets returned to stock. Rich problem gone and improved performance all throughout. The first time I hit Vboost with all the jets sorted out I was surprised at the amount of yank it had. The PO had installed the 170 mains and the stage 1 PAJ2 (behind the diaphragm) so it was grossly rich from idle on up. It was a different bike once this was solved.

I drilled out my slides and went with the shorter slide springs and it runs great. With the drilled slides you will want to make sure your are not running the stock springs.

Do you have stock exhaust?

 

[liptoss]

I'm attempting to equate what's been written here. From what I can gather, the Dynojet stage 7 kit is that all supplied mains will more than likely run too rich for most full aftermarket exhausts.
My brother has a Kerker and has the DJ Stage 7 165's installed and seems to run just about right without "sootiness".
Myself on the other hand, have a Hindle SuperSport 14" and 18" Stealth baffles. I have the 165s from Stage 7 installed and have some "sootiness" on the outlet tip.
I was thinking of using the DJ Stage 1 160s in my set up, but worried about being lean on top end.
Thoughts anyone?
Now, lastly, with the DJ Stage 7 kit. Who the hell would use the 175 mains? Someone running open headers?

 

[Fire-medic]

You can just grab a few coils of the stock springs, and use safety wire to wire them together, effectively shortening the stock springs, if you're really into the 'frugality' thing.

+1

I had the same fight you have. I had it running ok with the stage 1 needle. I'm at altitude so running 147.5 main jets, stage 7 needles and the rest of the jets returned to stock. Rich problem gone and improved performance all throughout. The first time I hit Vboost with all the jets sorted out I was surprised at the amount of yank it had. The PO had installed the 170 mains and the stage 1 PAJ2 (behind the diaphragm) so it was grossly rich from idle on up. It was a different bike once this was solved.

I drilled out my slides and went with the shorter slide springs and it runs great. With the drilled slides you will want to make sure your are not running the stock springs.

Do you have stock exhaust?