Help with what I need to do to scooter

[dingy]

Attached 2 PDF's that shows the 2 dyno runs I had at Thunder Friday.

There is a separate run for left & right side runs.

Reason for right & left runs with sniffer moved is I have a Marks 4-2-2 collector/header that does not tie the right & left banks together. I asked for a separate run with sniffer in both sides so I could see A/F readings from both banks.

Between left & right run he entered some info into PC which may have accounted for HP readings different between sides. He also said he could not hook up to COP's with his dyno, so he watched tach and manually entered RPM #'s.

Any suggestions on what I do to improve this will be appreciated.

Run down of what is in motor is below.

1300 block, milled .040" at block/head surface. Stock Venture pistons
Compression PSI is 185~195 on cylinders
VMax heads & cams from a 97 bike
150 main jets. 35mm VMax jetted carbs (originally from Venture, but jets changed, identical otherwise to VMax)
Marks 4-2-2 collector that does not have the right & left banks tied like the VMax does. Dyno run at Thunder had fairly wide open mufflers on.
VBoost tied into TCI as controller, starts to open at 4900 & fully open at 5900 rpms
VMax air box with K&N. 'Y' on top of lid removed.
VMax/FJR final drive
VMax 15" rear rim
COP's
Iridium plugs gapped at .032"
92 octane gas

Last three chart pictures are of Ignitech settings.

Gary

 

[bazwell]

Dude, removing the cross over pipe is not good. Not good at all.

As for your dyno sheets, they are bloody near on impossible to read!
Looks like it is as lean as hell until v-boost opens. Maybe shim the needles, and turn your idle mixture screws out a bit!

 

[dingy]

The Ventures don't have the crossover pipe that the VMax's do. Ventures tie together at the stock collector which is the junction point for the front & rear headers. The collector was replaced by the Marks header/collector.

Gary

 

[dingy]

Rescanned dyno sheets as a right & left side PDF. Much easier to read now.

Attached to 1st post.

Gary

 

[gamorg02]

my walkers don't have the crossover so while they might benefit from it, i would imagine they are not 'needed'.

that being said. i'm going to ignore the steep curve in both as far as what RPM it happens and assume its on both. looks like once you go to your mains, which on the vmax at WOT is around 4-4.5k rpms, you're way rich. i'd love ot see charts with vboost off completely to see how much of the rich dip is from vboost how much of it is the main.

i'd say thats at least 2-3 size main decrease and then you'll have to mess with the needles (which needles are you running)? maybe some stage 1 vmax needles could help?

 

[Lew L]

Just my $0.02 here but if your running the stock air box, you could probably gain a few HP with some modification there. I has been shown to be the restriction on the stock bike much less a highly modifidied one like yours.

Try running it with the "Y" removed or at least raised. Cost= $0.00

Lew

 

[dingy]

Just my $0.02 here but if your running the stock air box, you could probably gain a few HP with some modification there. I has been shown to be the restriction on the stock bike much less a highly modifidied one like yours.

Try running it with the "Y" removed or at least raised. Cost= $0.00

Lew

The 'Y' was removed, forgot to mention it.

Added to first post.

Gary

 

[dingy]

my walkers don't have the crossover so while they might benefit from it, i would imagine they are not 'needed'.

that being said. i'm going to ignore the steep curve in both as far as what RPM it happens and assume its on both. looks like once you go to your mains, which on the vmax at WOT is around 4-4.5k rpms, you're way rich. i'd love ot see charts with vboost off completely to see how much of the rich dip is from vboost how much of it is the main.

i'd say thats at least 2-3 size main decrease and then you'll have to mess with the needles (which needles are you running)? maybe some stage 1 vmax needles could help?

It has stock needles in it. New last winter. Sean Morley told me to do that to help a popping I was having.

Carbs were recently rebuilt almost completely, only 2 things not replaced that would be considered replaceable were sliders & enrichment rubbers. All jets, gaskets, rubber parts, diaphragms were new. Ultrasonic cleaned. Have just been synched. New rubbers on VBoost and carb bases.

Gary

 

[one2dmax]

A bit rich on the top end and for sure lean on the mid and bottom range. I know some aftermarket systems connect mufflers from opposite sides instead of the same sides. That may help you regain some of the "missing" power.

Sean

 

[dingy]

I was mistaken about the pipe setup. Just pulled a picture I have of Marks header I have on and it is hooking the diagonal cylinders together. 1 and 4 together with 2 & 3 together.

Picture attached of Marks on bottom & stock collector on top.

So smaller mains & shin needles may help then ?? 150 mains in now, would 145 be good choice?? Carbs are an extreme bitch to pull on this bike. The taller vboost unit makes them a pain to get out of there.

Gary

 

[naughtyG]

I can't read your sheets at all - what do they show? Don't you have a standard dyno sheet showing power and torque curves against rpm, with the a/f curve at the bottom?

 

[gamorg02]

I was mistaken about the pipe setup. Just pulled a picture I have of Marks header I have on and it is hooking the diagonal cylinders together. 1 and 4 together with 2 & 3 together.

Picture attached of Marks on bottom & stock collector on top.

So smaller mains & shin needles may help then ?? 150 mains in now, would 145 be good choice?? Carbs are an extreme bitch to pull on this bike. The taller vboost unit makes them a pain to get out of there.

Gary

i'd start at 145 but thats more of a guess. the stage 1 needles are almost identical to stock just adjustable and you may need to shim more than 1-2 shims once the mains are smaller ya know? i may have some that i'm not using if you wanted to try them out.

I can't read your sheets at all - what do they show? Don't you have a standard dyno sheet showing power and torque curves against rpm, with the a/f curve at the bottom?

its there, just use the a/f curve and look at the scale on the right.

 

[dingy]

I can't read your sheets at all - what do they show? Don't you have a standard dyno sheet showing power and torque curves against rpm, with the a/f curve at the bottom?

Attached below are picture formats of right left side pipe runs.

Gary

 

[dingy]

i'd start at 145 but thats more of a guess. the stage 1 needles are almost identical to stock just adjustable and you may need to shim more than 1-2 shims once the mains are smaller ya know? i may have some that i'm not using if you wanted to try them out.



its there, just use the a/f curve and look at the scale on the right.

What thickness shims are you refering to? I can get about anything made.

I also have an almost new stage 1 set of needles not being used.

What about the spring behind the slider? I had a stage 1 kit in it at first and Sean said to go back to stock. The sliders have been drilled. Not sure if I have the shorter stage 1 springs in with sliders or the stock longer ones.

Gary

 

[naughtyG]

That's a really weird AF curve for sure. I think I would want to try swapping for a rack of OEM Max carbs known to work well to compare, as the power looks quite low for a 1300 too I think.

 

[gamorg02]

What thickness shims are you refering to? I can get about anything made.

I also have an almost new stage 1 set of needles not being used.

What about the spring behind the slider? I had a stage 1 kit in it at first and Sean said to go back to stock. The sliders have been drilled. Not sure if I have the shorter stage 1 springs in with sliders or the stock longer ones.

Gary

i forget the thickness but its a half of a notch on the needles.

i'd stick with stock (longest) since you are going rich too soon as it is.

 

[veebooster]

Gary,
From what I saw it looked like you had a gutted set of stock mufflers on it. If you have a header and no restriction in your mufflers you have to have an open air box like morley's kit or stage 7. If you have stock air box put in some restriction in your mufflers or jet down.

Dale #2592

 

[dingy]

Gary,
From what I saw it looked like you had a gutted set of stock mufflers on it. If you have a header and no restriction in your mufflers you have to have an open air box like morley's kit or stage 7. If you have stock air box put in some restriction in your mufflers or jet down.

Dale #2592

Mufflers are somewhat gutted, there is one baffle left in them. I can not see light through them though.

Have took them back off since I got home and put a more tamer set of mufflers on that have all the baffles, but bike doesn't seem to be as perky as it is with the gutted set. Much easier on ears though.

It does seem to 'load' up at very low speed, and not have the snap to it when the throttle is cracked open with the more restrictive mufflers.

Thank you to all that have offered suggestions, carbs are not one of my strong points in general.

Gary

 

[bazwell]

Gary, another thing I've been thinking.

Because the AFR line starts off dead flat, it means that it is off the range of the dyno.
Otherwise it would be squiggly. So it is leaner even than it says it is.

I'm no dyno guru, but I might be a bit suspicious of a dyno that says the bike is so lean it is off the scale. Especially since the bike is obviously running at least reasonably well.

 

[one2dmax]

it's very common for light loads and the initial hit on the dyno to show almost off the chart lean. That's part of what helps to get your economy.