Tuning duals after choke removal- Help

[Shifty]

I think it is all good now. It seems I will need to rejet as I am at just over three turns out on my high's. My low needles are out 1-1/8 turns. I was having trouble tunning the lows because of the extreme difficulty of turning them with a vibrating engine. So I placed my first order with McMaster Carr on thursday and they rule, I had a surprise on my door by friday after work. I got some knobs like Jetski Solutions offers and some brass tube to extend the stock adjusters. Soldered those bad boys on that night and got to tuning on saturday. I feel they make tuning much easier, I can even tune the lows in sync.

The girdle hardware is just there, as I got bored and wanted to intall something. I have a Riva girdled head and cannot install without an aftermarket pipe, which I hope to have in a a week or so. I figure I will deal with jetting then and run the 3 + turns out on my highs until then.

Water in the carb is no longer an issue at this point, I have over two tankfulls through this thing now.

Factory pipe has "no comment" on the jetting for 38's with the chokes removed. Does anybody have a setup simlar to mine (185psi, limited pipe, choke removed)?

Thanks for the help with this issue,

 

[yamanube]

Factory pipe has "no comment" on the jetting for 38's with the chokes removed. Does anybody have a setup simlar to mine (185psi, limited pipe, choke removed)?

Did you look at their website?

Main Jet: 135 (130 stock)
Pilot Jet: 70 (stock)
High speed screw: 1 1/2 turns out from closed
Low speed screw: 1 1/4 turns out form closed
Needle & Seat: stock (55 psi)
Spring: Stock (95 gram)


I ran this on my '06 with chokes removed with no problems.

 

[augustaf]

Did you look at their website?

Main Jet: 135 (130 stock)
Pilot Jet: 70 (stock)
High speed screw: 1 1/2 turns out from closed
Low speed screw: 1 1/4 turns out form closed
Needle & Seat: stock (55 psi)
Spring: Stock (95 gram)

You can't get 55 psi p/o with a 95g spring. That would take a 115g spring, which I think is stock.

 

[yamanube]

Main Jet: 135 (130 stock)
Pilot Jet: 70 (stock)
High speed screw: 1 1/2 turns out from closed
Low speed screw: 1 1/4 turns out form closed
Needle & Seat: stock (55 psi)
Spring: Stock (95 gram)

You can't get 55 psi p/o with a 95g spring. That would take a 115g spring, which I think is stock.

I didnt supply the numbers just followed the directions that came with the pipe, 135 main 70pilot and stock N/S and spring.

 

[Shifty]

Well I just ordered my pipe... I got antsy, and they are running very low on inventory, should be here friday. I would like to get the right jets for my carbs today also... seems like at 3+ turns out at the moment this pipe will require even more....which isnt goint to happen. These specs:

Main Jet: 135 (130 stock)
Pilot Jet: 70 (stock)
High speed screw: 1 2 turns out from closed
Low speed screw: 1 1/4 turns out form closed
Needle & Seat: stock (55 psi)
Spring: Stock (95 gram)

are for the chokes in, and aftermarket flame arrestors, seems like the aftermaket F/A would balance out the vacuum loss the choke removal created?

Are the other specs stock (N&S, Spring)?

 

[yamanube]

Well I just ordered my pipe... I got antsy, and they are running very low on inventory, should be here friday. I would like to get the right jets for my carbs today also... seems like at 3+ turns out at the moment this pipe will require even more....which isnt goint to happen. These specs:

Main Jet: 135 (130 stock)
Pilot Jet: 70 (stock)
High speed screw: 1 2 turns out from closed
Low speed screw: 1 1/4 turns out form closed
Needle & Seat: stock (55 psi)
Spring: Stock (95 gram)

are for the chokes in, and aftermarket flame arrestors, seems like the aftermaket F/A would balance out the vacuum loss the choke removal created?

Are the other specs stock (N&S, Spring)?

I ran this tuning with a bpipe, ada head, stock 38s, chokes removed, OEM F/A. From the way you are describing it sounds like your tuning is pretty far off. Is it that hard to try what the pipe manufacturer recommends? Change 2 jets, turn 4 screws and leave the rest. Did the same on a buddies boat and it ran great also, I would assume if you do this and it doesnt seem to run right or at least very close, there is probably another problem.

*edit I read somewhere that the '08 used a different spring and possibly a different N/S. Do some reading, you may need to change those to whatever came stock on the pre '08 models.

 

[Dustin Mustangs]

So I placed my first order with McMaster Carr on thursday and they rule, I had a surprise on my door by friday after work. I got some knobs like Jetski Solutions offers and some brass tube to extend the stock adjusters. Soldered those bad boys on that night and got to tuning on saturday. I feel they make tuning much easier, I can even tune the lows in sync.

Care to share some part numbers? I'd like to rig something like this up on a couple of diff boats...

 

[Shifty]

Sure,

Knob - 6332K34
Brass Tube - 7782T111

Is seems they changed the quantities and sizing but I think this is they right ID tube, it is not that critical as you will have to trim regardless.

It was about $30 shipped

and they look great.

 

[Mark44]

Fine looking job.

Mark44