Dyno run

[warp1]

View attachment vmax dyno.pdf

Bike is a stock '98. K&N filter, Marks 4:2, 2 inch cans, 152.5 jets. Was happy with the 120 ponies....but as you can see, way too rich. Should have left the stock jets (150) in.

A friend in town recommended just dropping 1 jet size (back to 150), and make up for any remaining richness with an air box mod...

Dyno tech recommended dropping 2 jet sizes and going from there.

You guys have any thoughts based on what you've seen in the past?

Oh....goal is not to grab every available hp, just a well tuned, safe mixture bike.

Thanks, Bill

 

[KJShover]

View attachment 23848

Bike is a stock '98. K&N filter, Marks 4:2, 2 inch cans, 152.5 jets. Was happy with the 120 ponies....but as you can see, way too rich. Should have left the stock jets (150) in.

A friend in town recommended just dropping 1 jet size (back to 150), and make up for any remaining richness with an air box mod...

Dyno tech recommended dropping 2 jet sizes and going from there.

You guys have any thoughts based on what you've seen in the past?

Oh....goal is not to grab every available hp, just a well tuned, safe mixture bike.

Thanks, Bill

Stock main is 152.5.
I'd go back to the 150

 

[SpecOps13]

4-2-1 Exhaust will generally require 2 sizes at sea level, 4-2 may need 1. I'm running stock 152.5 and still a touch lean. Same 4-2 Mark's as you...
By your chart, you're running rich for sure. Really good HP Numbers though. Mine's almost flat at 14:1..

 

[warp1]

Everyone keeps saying 152.5's are stock....but I know I pulled 150's out of mine and pretty positive they'd never been touched....

Specops...I wonder if you just have better airflow than me? weird they'd react so differently with the same pipes. Thanks for the responses....

 

[KJShover]

Everyone keeps saying 152.5's are stock....but I know I pulled 150's out of mine and pretty positive they'd never been touched....

Specops...I wonder if you just have better airflow than me? weird they'd react so differently with the same pipes. Thanks for the responses....

If you have 150's in your '98, someone has been in your carbs.

 

[[email protected]]

If you have 150's in your '98, someone has been in your carbs.

+1
152.5 is stock.
150 is one size leaner
147.5 is two sizes leaner.

I would buy a set of 147.5 jets. Sounds like you should already have 150's. Play around with those two sizes. Run the smallest main you can and still have th bike run properly.

 

[warp1]

Wow...hard to believe. Thanks guys...I'll keep you updated

 

[06VMAXIMUS]

Yes, please keep us updated! I have the exact same setup as you, but unfortunately no dyno near me. I am running the 150's now. I'm very interested in the results you have/will come up with.

 

[mattmullins]

California bikes come with 150 mains stock

 

[dannymax]

Haynes says:
'96 - '03
Main Jet: European models.........150
49-state and CA.........152.5

 

[VMax-Mike]

If you have a full system and you are only at 152.5 and the bike runs good but a little rich I would try to get more air to the motor and make more hp. The pipe should keep up. A used air box dont cost much and not hard to install. talk with your dyno tech and say i got $100 and i can drop it with you for a week. resurch other mode's and help him with what to do to your box. find a back up box first. if he cant get the air fuel ratio right you can always rejet. call sean morley and give him your dyno numbers and see if he can help you find more hp.

 

[sdt354]

If you have a full system and you are only at 152.5 and the bike runs good but a little rich I would try to get more air to the motor and make more hp. The pipe should keep up. A used air box dont cost much and not hard to install. talk with your dyno tech and say i got $100 and i can drop it with you for a week. resurch other mode's and help him with what to do to your box. find a back up box first. if he cant get the air fuel ratio right you can alwa

I'm in the middle of a tune situation similar to yours. I have a Marks 4-2 full exhaust. Otherwise I?m stock. I have the stage Steve-o oil line tee'd to my air box from my oil cap-owner creation. I have lots of time, but money-no ? So, with the rich midrange needles I'm using, and soft, short diaphragm return springs, I'm still a bit rich. Setting now is-2nd clip, no spacer (from the flat end). I could possibly go to 1st clip position with a 3/4+ cut down shim. Get the caliper and sharpening stone out, turn on the tv and grind away.
With the y shimmed 3/8's it ran better (thanks to KJ), with the y removed it ran even better.(I know this is contrary to what I've read, but I do stuff like this..Lol) a/f/ 2 1/8 -2 1/4 out is what's working right now. I have 152.5 mains now. I'll be putting 150 mains in next. I got a set of 147.5's from Rov when I saw him recently, good to have in case I need them. I might have to put the air box parts back on with smaller mains.
I do 1 thing at a time only, especially in unknown waters, then test ride a FEW times. I then Plug read after a clean shut down if possible. There's no hesitation in any RPM range, and crisp throttle response right now. I?m getting about 36-37 mpg and think I can do better. I also get other riders to follow me and observe my exhaust whenever I can. I'll dyno when I think I'm close. Wish I had the use of a dyno for a day. My bike's running well, though what I'm doing IS time consuming. But, I'm having a blast and learning a lot too. I?ll find a dyno before winter if I can.
Steve-o

 

[gamorg02]

If you have a full system and you are only at 152.5 and the bike runs good but a little rich I would try to get more air to the motor and make more hp. The pipe should keep up. A used air box dont cost much and not hard to install. talk with your dyno tech and say i got $100 and i can drop it with you for a week. resurch other mode's and help him with what to do to your box. find a back up box first. if he cant get the air fuel ratio right you can alwa

I'm in the middle of a tune situation similar to yours. I have a Marks 4-2 full exhaust. Otherwise I?m stock. I have the stage Steve-o oil line tee'd to my air box from my oil cap-owner creation. I have lots of time, but money-no ? So, with the rich midrange needles I'm using, and soft, short diaphragm return springs, I'm still a bit rich. Setting now is-2nd clip, no spacer (from the flat end). I could possibly go to 1st clip position with a 3/4+ cut down shim. Get the caliper and sharpening stone out, turn on the tv and grind away.
With the y shimmed 3/8's it ran better (thanks to KJ), with the y removed it ran even better.(I know this is contrary to what I've read, but I do stuff like this..Lol) a/f/ 2 1/8 -2 1/4 out is what's working right now. I have 152.5 mains now. I'll be putting 150 mains in next. I got a set of 147.5's from Rov when I saw him recently, good to have in case I need them. I might have to put the air box parts back on with smaller mains.
I do 1 thing at a time only, especially in unknown waters, then test ride a FEW times. I then Plug read after a clean shut down if possible. There's no hesitation in any RPM range, and crisp throttle response right now. I?m getting about 36-37 mpg and think I can do better. I also get other riders to follow me and observe my exhaust whenever I can. I'll dyno when I think I'm close. Wish I had the use of a dyno for a day. My bike's running well, though what I'm doing IS time consuming. But, I'm having a blast and learning a lot too. I?ll find a dyno before winter if I can.
Steve-o

FYI steve, the dyno up near me is pretty reasonable, i think $50 for 3 runs, and they give you a print out. i'm sure they'd do a WOT, 1/2 throttle and 1/4 throttle run each if you wanted or something. i know money short but figured i'd mention it, once you think you got it close.

 

[sdt354]

FYI steve, the dyno up near me is pretty reasonable, i think $50 for 3 runs, and they give you a print out. i'm sure they'd do a WOT, 1/2 throttle and 1/4 throttle run each if you wanted or something. i know money short but figured i'd mention it, once you think you got it close.

Thanks Garrett, I'm almost ready. and would like to do it soon. That way I really know where I'm at with a/f at different throttle positions/rpms.plus hp and torque $50 is resonable. Send their info? Maybe a few of us can go the same day.
Steve

 

[sdt354]

Came back from a hard 120 mile run tonight, last 50 near triple digits. The plugs were very close, a nice whitish tan. I think with 150 mains It might a bit lean. Might have to take some air away. Great throttle responce under load.

 

[gamorg02]

here ya go bud:

http://maps.google.com/maps?hl=en&rlz=&=&q=harry%27s+machine+northboro+ma&gs_sm=e&gs_upl=28l2043l0l2986l14l10l0l0l0l0l228l1486l2.6.2l10l0&um=1&ie=UTF-8&sa=N&tab=wl

Just don't ask for Harry, haha. Rick Stetson is the main guy there, been building drag bikes since the 70's. His name is around the web if you google it. If we can't find the leak or whatever i may be interested in putting my bike on the dyno too to see what that off throttle issue might be.

don't quote me on the $$ either tho, i'd call and ask.

 

[warp1]

OK...first off, sorry for the confusion. Definitely came with 152.5's (I blame it completely on my 40+ year old brain ).

Got a set of 150's from Sean and put those in. Seat of the pants seemed crisper, but something about the sound just didn't seem right. Occasional idle issues too...but seemed stronger than it was.

About then I realized I still hadn't synch'd the carbs yet, and my buddy broke his kit. So ordered the carbtune (based off reviews on here) and synch'd them the day they came in. Holy shit...1+2 were off compared to 3+4 by nearly the whole scale of the guage. Once all equal, had to drop the idle screw 2+ full turns. I swear, it's an entirely different bike now! All sounds are puuuuurrrrfect, and incredibly crisp.

Went on a 250 mile cruise the next day and averaged 39 MPG (at about 60 MPH) compared to the 30 I was getting. This is 1 happy VMax owner

Will redyno when they can fit me in....verify good mixture

 

[SpecOps13]

You are currently running just a bit richer than my 94. I averaged 40.5 mpg 2 up on last weeks ride. So, you should be in the right ballpark for good HP...


Good Luck...