coffman vs. b pipe

[Nuklear6]

I know it very obvious that the pipe of choice is the factory b pipe for any yamaha 701. But i just find it out of control that a used (and often not so perfect) b pipe goes for 550 to 600 dollars. When i already have a very nice coffman full exhaust on my square nose jet. I have a very nice 61x/61x w/ some mild cylinder porting and very nice case porting with a 185psi west coast head ready to go in my square. My question is has anyone ever compared the coffman vs the b pipe on the same ski? How much am i give up by staying with the coffman and not spending the big money for an over priced used b pipe?

 

[surfjunkie]

i agree on the price of used b pipes. i would ride a ski with a coffman pipe and be stoked about it.

if everyone here says you have to run a b-pipe, and they will, and you decide to get rid of your coffman cheap...lmk

plus aren't coffman's easier to install the way the expansion chamber is two pieces??

unless they have a problem with not holding up due to their design, i would vote run what you got.

 

[OCD Solutions]

unless they have a problem with not holding up due to their design, i would vote run what you got.

The Coffman sizzler pipes are bulletproof.

 

[orangefinger]

coffmans is a great pipe used to have 2 of them on my SN's , restrict it and you will be astonished how much it pushes

 

[suva]

Factory pipe definitely made more power than my Coffman's setup, but I don't think it will hold up as well in the long run. The Coffman's is beefy. Coffman's can felch a pretty penny used too, so keep that in mind.

 

[tnj4life]

Ive never tried a bpipe but im happy with my coffman. Good quality and nice hit. For the price its hard to beat. I dont know if i'll ever shell out the $$ for a bpipe either.

Orangefinger, how do you restrict your coffman?

 

[LIVE2RIDE Powersports]

Ive never tried a bpipe but im happy with my coffman. Good quality and nice hit. For the price its hard to beat. I dont know if i'll ever shell out the $$ for a bpipe either.

Orangefinger, how do you restrict your coffman?

On my pipe i only run water to the headpipe with a jet in it. It got louder but totally worth the extra tug.

 

[tnj4life]

On my pipe i only run water to the headpipe with a jet in it. It got louder but totally worth the extra tug.

No chance of smokin a coupler? I remember you telling me that you didnt run a cooling line to your stinger as well, that is where your noise is coming from. Your waterbox stays pretty much empty. On my js440/750 I did the kawi 650 pipe mod and filled the water passage on the headpipe and drilled to 1/8 to restrict. I may do like you did and not run water to the stinger on that ski, I have been runnin it there though. Does it sound horrible? what kinda jet did you stuff in the line?

 

[DC SUPERJET]

I have a b-pipe on my rn, and I have ridden a 61x with a coffman and it was very close to the same. Save your money and buy some tubbies instead.

 

[LIVE2RIDE Powersports]

No chance of smokin a coupler? I remember you telling me that you didnt run a cooling line to your stinger as well, that is where your noise is coming from. Your waterbox stays pretty much empty. On my js440/750 I did the kawi 650 pipe mod and filled the water passage on the headpipe and drilled to 1/8 to restrict. I may do like you did and not run water to the stinger on that ski, I have been runnin it there though. Does it sound horrible? what kinda jet did you stuff in the line?

It's really not that loud, i even run a tdr. I rode my ski for 30 mins and came in to check the pipe and it didnt steam, nor was it to hot to touch. It did actually raise the nose alittle bit and threw off the steering alittle, but i got the hang pretty fast.

 

[Mouthfulloflake]

Ive done EXACTLY what are you asking.

removed a coffman pipe, and put on a B pipe, on the same boat, same engine ( 61x with a head)

took me forever to get the B pipe tuned to work as well as the coffman, after drying it out so much that it nearly melted it finally made more power ( SLIGHTLY) than the coffman.

In retrospect, drying out the coffman pipe, would have made more power too most likely.

there is little to NO difference in the power between those two pipes in my opinion on my 61x boat.

possibly a larger CC engine might make more power with the B ( larger chamber) im not sure though.

save your money.

I know it very obvious that the pipe of choice is the factory b pipe for any yamaha 701. But i just find it out of control that a used (and often not so perfect) b pipe goes for 550 to 600 dollars. When i already have a very nice coffman full exhaust on my square nose jet. I have a very nice 61x/61x w/ some mild cylinder porting and very nice case porting with a 185psi west coast head ready to go in my square. My question is has anyone ever compared the coffman vs the b pipe on the same ski? How much am i give up by staying with the coffman and not spending the big money for an over priced used b pipe?

 

[OCD Solutions]

How many of you increased the Coffman Manifold bore to match the 701 exhaust port? Wasn't it designed for the 650 with smaller ports?

Mine was matched when I got it and I was clued in years later that it even needed to be, I just assumed it was meant for the 701.

 

[Mouthfulloflake]

I matched mine to a 701 gasket, took half an hour, pretty simple.
I dont even think I polished it very well ( it was a few years ago)

How many of you increased the Coffman Manifold bore to match the 701 exhaust port? Wasn't it designed for the 650 with smaller ports?

Mine was matched when I got it and I was clued in years later that it even needed to be, I just assumed it was meant for the 701.

 

[orangefinger]

coffmans manifold of the 650 needs to be dremeled open to fit larger 61x as does the gasket, I had best results restricting the line to the Stinger to 4mm anything more it would get very hot

 

[tnj4life]

How does the cheater pipe setup compare to an actual real aftermarket setup? Just wondering cause im considering to use them on a couple of my skis. They are the cheapest setup and must be better than the stock exhaust.

 

[MES4888]

anyone have results with a 62t?

 

[95FX1]

bumping this thread as im bout to put the coff pipe on my 701 and was looking for some tricks for it...all great options above^^

i was also looking for advice on how to run the cooling lines??
i have a milled stock head...

im also gonna trace the gasket on the head and open it up some to match up

any thoughts?
thanx

 

[kevbo]

There is no tricks to making it work. Run a hose from the head to the headpipe and out a 1/4" pisser. The stinger barb should be factory restricted but could be taken down to .100". Ive been running this on a 50mph ski for many years. If you want the most performance work on the prop and nozzle to get the rpm where it needs to be, at least 7000.

 

[superjetbrad]

iam about to put a coffman on a 62t anyone done that cuz i would love to hear how it worked

 

[brett]

i got both on stock 61x motors (one with a head) im always impressed by the coffmans.