Jetting specs that I have used

[corkycat]

so in english whats the reason for drilling this restrictor out?

[OsideBill]

Drilled out restrictors with a 90 main jet in the return line to equalize fuel pressure

so in english whats the reason for drilling this restrictor out?

Is this good enough from the first post?

[YamahaPat]

How about triple piper with stock carbs?

[RDH]

Thanks for the jetting

what highs are you gonna use for your triple piper? still 1200?

i was running 140,rpms to low. so i tried 137.5,choked at half throttle+. now ive got in 142.5 and havent ran it yet.

[YamahaPat]

1300 top end.

145/115/2.0

Should be good.

[YamahaPat]

With triple pipes...DEF go Novi's! What a HUUUUUUGE difference!

[sleeper_dave]

I'm putting a 1300R motor in my 1200R. It's a 1300 power valve motor, all stock except for these cylinders http://greenhulk.net/showthre...ight=cylinders. It's put together with one base gasket. Ports are "cleaned up" and cylinders are decked for slightly higher compression.

I will be using stock MY2000 1200R carbs (are they the same as the 1300 carbs?). Stock 1200 exhaust except the manifold from the 1300. Stock 1300 reeds unless someone has some aftermarket ones for sale cheap.

I currently have the stock airbox but I will probably go to flame arrestors just for simplicity / cleanliness in the hull. The 1300 motor will be premix as it already has a blockoff plate and I can eliminate the plumbing while the motor is out. I'll be running premium, generally 92-93 octane.

I want to put it together and ride. I don't want to tweak for max power, I want to be close but safe, and then just ride the piss out of it. I don't have time, don't have a tiny tach, and don't have the patience to get the last little bit out of it so I just need a good safe starting point out of the box.

I don't want to go to a primer kit and I plan to keep the choke. I will also keep the accelerator pump unless that's considered inadvisable. I can disconnect the accelerator pump and just leave it in place as a primer (as suggested on cajundudes tech pages) if that's the best method.

I've read a lot of threads and this seems to be the place to ask... so... what jetting, settings, etc?

[sleeper_dave]

After looking at a lot of threads and a lot of posts - i'm thinking 115/135 on pilot / main jets.

But I still don't know what to do about pop-off pressure. I'm going to order the pro-k flame arrestors... what pop-off pressure should I be shooting for?

I need to order parts soon so hopefully someone will reply with some good info...

[dav_dman]

After looking at a lot of threads and a lot of posts - i'm thinking 115/135 on pilot / main jets.

But I still don't know what to do about pop-off pressure. I'm going to order the pro-k flame arrestors... what pop-off pressure should I be shooting for?

I need to order parts soon so hopefully someone will reply with some good info...

you might have to drop to 130 mains if the porting is only cleaning up. But start with 135's.

From post#1 in this thread:
1300 GPR single piper conversion (Ported), Flame arrestors, Advent CDI Yam 84 Engine, No accelerator pump

Stock, Novi modified, Prok Atomizers or RPM modified (Stock Bore)

115 Pilots
135 Mains
1.5 N/s
80 Gram Spring

[RDH]

I'm putting a 1300R motor in my 1200R. It's a 1300 power valve motor, all stock except for these cylinders http://greenhulk.net/showthre...ight=cylinders. It's put together with one base gasket. Ports are "cleaned up" and cylinders are decked for slightly higher compression.

I will be using stock MY2000 1200R carbs (are they the same as the 1300 carbs?). Stock 1200 exhaust except the manifold from the 1300. Stock 1300 reeds unless someone has some aftermarket ones for sale cheap.

1300's never came with carbs, so you'll only ever have 1200 carbs
I currently have the stock airbox but I will probably go to flame arrestors just for simplicity / cleanliness in the hull. The 1300 motor will be premix as it already has a blockoff plate and I can eliminate the plumbing while the motor is out. I'll be running premium, generally 92-93 octane.
definitly get FA's your motor will actually be able to breath
I want to put it together and ride. I don't want to tweak for max power, I want to be close but safe, and then just ride the piss out of it. I don't have time, don't have a tiny tach, and don't have the patience to get the last little bit out of it so I just need a good safe starting point out of the box.

I don't want to go to a primer kit and I plan to keep the choke. I will also keep the accelerator pump unless that's considered inadvisable. I can disconnect the accelerator pump and just leave it in place as a primer (as suggested on cajundudes tech pages) if that's the best method.
primer kit is a must if you wanna start your boat quickly when its cold

I've read a lot of threads and this seems to be the place to ask... so... what jetting, settings, etc?

we have a 1200 with 1300 non pv jugs and we run 130 highs,, 135 is to fat

[sleeper_dave]

I think i'll keep the accelerator pump and just remove the cam, then if I need it as a primer i'll just pump it a few times. I'll keep the choke plates. Not too terribly worried about cold starts. Maybe i'll order a primer kit, we'll see. I'm already spending way too damn much on this thing.

I think i'm going to go with the 115/135's and if it's too fat i'll drop to 130 mains. I'd rather run it a bit fat than too lean. Compression is bumped up a bit and it's "lightly" ported, so i'll start higher and back it down as needed. I found another thread (http://greenhulk.net/showthre...hlight=pop-off) where people are suggesting anywhere from 125-135 mains. I do plan to run pre-mix, run in colder weather (I will run in 40 degree water / 60 degree air spring and fall), and run it hard, so I want a safe setup more than anything.

One thing that I don't see accounted for in any of these threads is pre-mix vs. oil injection. If you pre-mix at 32:1, you're going to run 3% leaner across the board than if you're running oil injection. Unless i'm missing something and the oil just injected into the carb bowl or something. Same with running E10... you need to run a little fatter if your fuel has 10% ethanol in it. I forget the % off the top of my head, though. I'm going to pre-mix so i'm going to start on the fat side.

Based on a bunch of other threads and a bunch of surfing I was narrowed down to 1.5/95 or 1.5/80. I'll go with the 1.5/80 and disable the accelerator pump, hopefully that does the trick!

[sleeper_dave]

Where do I buy the jets? 4-tecperformance doesn't have 135 mains. I just ordered everything else.

Holy shit. Just spent 313.60 on carb parts. 3 rebuild kits, t-handle kit, 3 n/s sets, 3 springs, 3 pilot jets, 3 main jets (130's). Still need to find 135 main jets.

Ouch.

[jbracing]

Best jetting specs 1390 ?

[QUOTE=OsideBill;411379]Fercho I have a Lowell ported 1390 build in progress with 44 I body Black Jack conversion.

Art Recommends

110 lows 1 turn
150 highs start at 1.5 turns and tune down
2.5 N&S Black spring

OsideBill,
Just finishing building the 1390 (87 mm piston's)
-Lowel ported cylinders+Lowel stock ported Head (last porting update)
-single pipe
-48mm Novi's,3 mikuni external pump's
-V-force III Cages
Have you tried Art jetting recommendation? If not asking too much,what do you recomend to start? wich jetting+return line main jet?
Tks JB

[OsideBill]

Those recommendations are for BlackJacks and will not work on Novi's.

I have not set Novi's up on a 1390 Single I have collected some data from the net, but do not have experience with it yet. 2.3 N&S 95gr spring 135 pilot 180 Maybe somebody will chime in who is running this set-up

[jbracing]

Also have a set Black Jack's carb's in the box,will start with them first.
On 1390 single with black jack's wich jetting to start? if you have any experience with those.
Appreciate all comment's
Tks JB