Help me tune my B pipe

[Mouthfulloflake]

61x, msd enhancer, light flywheel, timing advanced, ada girdled head, 37cc domes ( 180 psi)

stock SBN44 carb, factory B pipe, with the tail cone mod done to it ( reduced ID of chamber output)

right now it starts and runs, but its really got LESS power than the coffman sizzler pipe that it replaced


top screw is 2.5 turns open, mid and bottom screws are closed.

pipe and chamber are hot to the touch, but NOT sizzle water hot.

right now the headpipe output goes straight to the stinger ( no pisser TEED in)

jetting is 120/145 2.0NS 95 gram spring.

any ideas what im missing here?

 

[The Penguin]

see Supertune's response here:

http://www.x-h2o.com/threads/37858/post-518612#post518612

top & mid closed, bottom open 1 turn as a starting point

 

[Mouthfulloflake]

ahhhhhaaaa good info there.

dangit though, I dont guess its possible to adjust them with it installed huh?

it was a BEAR for me to install!

 

[ChrisGooch]

Mouth, you should be able to adjust it just fine with it installed. I'm able to reach the bottom screw and I have some thick hands.

 

[Mouthfulloflake]

I reached under there and I can loosen the locknut, but Need to cut an allen wrench down to fit the screw.

also, here is a pic of what appears to be a modification on the end of the chamber, the ID has been reduced.

 

[750SX]

It will run like a mofo on the top end with the top and mid closed and the bottom open 1 turn. I run my top screw at 1/8, middle at 1/2 and bottom closed. Adjusting the b-pipe is a give or take thing. Whatever adjustment you make, you will make one thing better and another worse. You just have to play around and figure out what you like. Good luck it's fun! That bottom screw is a real pain to do in the hull, but it beats pulling the headpipe again. I've been there haha.



EDIT- Get a tee the line and a jetworks valve in that stinger line asap! Even with garbage pipe tuning, those two things will make a huge difference. You are loading your waterbox with a T O N of water!

 

[Gainera2582]

Try just under 1 turn open on the top. You will be surprised at how much of a difference it makes.

I run mine about 1/2 turn out from the top and it rips.

 

[brentR]

T that headpipe you prob have too much water in there
2.5 turns out on top? wow!
im at bot,mid closed and top is open like 1/2 a turn and it just sizzles

 

[waxhead]

I find it you run the top and mid screws open it has no roll on
and its like having to short a prop
it will burst through the power to fast
a b-pipe is all about throttle response and low end
I cant see for the life of me why people would try and get it to go flat at about 4500-5000 k
Put a tacho on your boat and watch the rpm climb when you grab the throttle

 

[Mouthfulloflake]

well, still un able to make it work like I want it to.

tried bottom screw open and none of the others, tried bottom and mid closed...
anyway....
here are some pics of the piston wash.

pto looks good to me.

mag cylinder looks odd.

BUT, my start/stop died on me and I swam it in, and then upon trying to recrank the old relay stuck and the starter was spinning for 10-12 minutes until I got it on bank and removed the battery cable.

anyway... any thoughts on this pattern?

 

[Shonuff]

I'd go back to the sizzler and see if the problems disappear.

 

[Freakrider]

It will run like a mofo on the top end with the top and mid closed and the bottom open 1 turn. I run my top screw at 1/8, middle at 1/2 and bottom closed. Adjusting the b-pipe is a give or take thing. Whatever adjustment you make, you will make one thing better and another worse. You just have to play around and figure out what you like. Good luck it's fun! That bottom screw is a real pain to do in the hull, but it beats pulling the headpipe again. I've been there haha.



EDIT- Get a tee the line and a jetworks valve in that stinger line asap! Even with garbage pipe tuning, those two things will make a huge difference. You are loading your waterbox with a T O N of water!

Mouth...some run this... my jetworks valve is set up OFF THE 90 DEGREE with a tee just past the top head pipe and the straight through going over board....equals less water to the stinger/waterbox...hits like a mofo

 

[Mouthfulloflake]

If I am understanding you guys correctly, I have ran that valve in BOTH locations, with everything from NO ball and spring in it, to 3 washers in + ball and spring in it, and it makes a difference in the SOUND of the exhaust, but I cant get the rpms out of it still.

I will try and take a pic of the hose routing, and the variations I have tried.

Ive been reading here, and one thing Ive come across is how water pressure, and pump pressure can effect this.

when I swapped to the concord impeller, I noticed MORE volume and pressure out the pisser ( this was a few years back)..
is it possible ive simply got an excessive amount of water coming into the bottom of the exh manifold?

 

[SuperJETT]

Please remember that 1 turn open on one person's ski might be completely different flow than one someone else's due to differences in water pressure. You have to tune *your* pipe.

 

[Mouthfulloflake]

I have been trying to do just that.

Ive talked to some folks who simply set the screws as they were told, and have been running them that way.

I wish this one would allow me to do that.

ive moved the top and middle screws all over the map, all combinations, and last sunday starter messing with the bottom screw.

its not much better from the short amount of time I got to tune and test.

thats why I pulled the head, thinking I must have some other issue going on.

I cant find anything else wrong with it though.

Please remember that 1 turn open on one person's ski might be completely different flow than one someone else's due to differences in water pressure. You have to tune *your* pipe.

 

[Crab]

Please remember that 1 turn open on one person's ski might be completely different flow than one someone else's due to differences in water pressure. You have to tune *your* pipe.

Jett's right, one turn may be too much on yours, heat that pipe up a bit.

 

[superx2]

he's already melted the hel out of everything under the hood

 

[Mouthfulloflake]

Ive tried 1 turn, 1/2 turn, 1/4 turn, all over the map, combinations of different screws..

seriously, im having a hard time between TOO hot, and TOO wet, im sure its a fine line, but dang...

this is my next attempt.

open the bottom screw ONLY 1/8 turn.

if it melts a hose, open it slightly.

if it doesnt melt a hose, close it slightly.

 

[Mark44]

o

Ive tried 1 turn, 1/2 turn, 1/4 turn, all over the map, combinations of different screws..

seriously, im having a hard time between TOO hot, and TOO wet, im sure its a fine line, but dang...

this is my next attempt.

open the bottom screw ONLY 1/8 turn.

if it melts a hose, open it slightly.

if it doesnt melt a hose, close it slightly.

Well thats one way of doing it....I guess.......

Mark44

 

[SuperJETT]

In that case, I'd pull the headpipe, pull all 3 set screws out, make sure the holes are clean and not built up with carbon, then test it with a garden hose to make sure they flow and are adjusting properly.