factory pipe I.D.

weston

weston

Location
Oregon
so i Finlay got the pipe i have been waiting for to complete my build and I'm a little worried about the head pipe the inner diameter is smaller then the new pipe on my fx1(fx1 pipe is a SJ pipe with a mod chamber)
the pipe i just received came off a blaster 1 the chamber is a limited chamber.
do i have some head pipe for something else or is there a slight difference in the older head pipes compared to the newer head pipes or is this for a 650 hopefully the pictures help
also if you could tell me why one pipe says FACTORY B PIPE and the other says B FACTORY PIP

I'm thinking its an old head pipe but i would like to know what you think
 

Attachments

  • fp 001.jpg
    fp 001.jpg
    85.4 KB · Views: 45
  • fp 007.jpg
    fp 007.jpg
    39.7 KB · Views: 44
  • fp 008.jpg
    fp 008.jpg
    82.2 KB · Views: 70
  • fp 010.jpg
    fp 010.jpg
    111.4 KB · Views: 107
  • file002.jpg
    file002.jpg
    31.2 KB · Views: 49
Last edited:
tipafew

tipafew

Location
Grand Rapids, MI
There is a SLIGHT difference from the old ones to new ones, but what you have is a BIG difference. I don't know for sure, but I would guess it's a 650 pipe or something.......curious what other people think.
 
Waternut

Waternut

Customizing addict
Location
Macon, GA
The bigger diameter I.D. should help make more power. I don't know why the one says B Factory pipe but the one with block letters looks like it was stamped by some guy in his garage. Never seen one with all block letters before.
 
snowxr

snowxr

V watch your daughters V
Location
Waterford, MI
The early b's were about 42mm, they have grown over the years as other changes were made. Just match the headpipe and manifold to the diameter that works for your motor. Search on X and you'll find some threads that deal with this.
 
SUPERTUNE

SUPERTUNE

Race Gas Rules
Location
Clearwater Fl.
If your running a 701cc, the new pipes from Factory Pipe are 47.25-47.50mm now as the older headpipe size as stated by snowxr were 42mm. Just port match up to the newer size. You shouldn't need to worry about thickness as you most likely will not break through if your careful with a die grinder.
 
A

aramis

Location
Rochester, NY
Supertune, any chance you can answer a few dumb questions for me? I want to open up the diam. of my headpipe and manifold and don't want to screw it up. I've read the other threads about this, but still wasn't sure and figured this was a recent/relevant thread to post in.

- my stock diam. is right around 43mm, and I think I want to open it up to 47mm, right? This is a stock 701 except for 185psi head and enhancer.

- the new gaskets I received from FP last Fall are a 46mm diameter, and when lining up the bolt holes the hole is off-center...is 46mm big enough, or do I go to 47? And if so, should I re-center the hole? If memory serves the gasket center is off-center to the rear of the boat.

- should I expect to have to do any carb tuning as a result of this mod? I've noticed some low-rpm detonation or misses (not sure which) since installing the MSD enhancer and coil on this engine/pipe setup. I'm going back to (an all-new) OEM coil, but figure the issue could be related to the restricted exhaust diameter...?

Any help is greatly appreciated...I'm in China at the moment and will want to get this ski back together ASAP when I return, and don't want to be so anxious that I overlook something!
 
Last edited:
R

restosud

smaller dia can cause pinging.
bore it to 47 or so and you'll be fine and align both holes then match the gasket to the pipe.
your jetting should be ok as is assuming it's right to begin with.
 
SUPERTUNE

SUPERTUNE

Race Gas Rules
Location
Clearwater Fl.
aramis said:
Supertune, any chance you can answer a few dumb questions for me? I want to open up the diam. of my headpipe and chamber and don't want to screw it up. I'm read the other threads about this, but still wasn't sure and figured this was a recent/relevant thread to post in.

- my stock diam. is right around 43mm, and I think I want to open it up to 47mm, right? This is a stock 701 except for 185psi head and enhancer.

- the new gaskets I received from FP last Fall are a 46mm diameter, and when lining up the bolt holes the hole is off-center...is 46mm big enough, or do I go to 47? And if so, should I re-center the hole? If memory serves the gasket center is off-center to the rear of the boat.

- should I expect to have to do any carb tuning as a result of this mod? I've noticed some low-rpm detonation or misses (not sure which) since installing the MSD enhancer and coil on this engine/pipe setup. I'm going back to (an all-new) OEM coil, but figure the issue could be related to the restricted exhaust diameter...?

Any help is greatly appreciated...I'm in China at the moment and will want to get this ski back together ASAP when I return, and don't want to be so anxious that I overlook something!
Click to expand...

Go back to the OEM coil.(Enhancer is fine) The red MSD coils are junk! They have caused misfiring for me every time I used one, I had to lower the sparkplug gap to .018 to get them not to misfire!
 
You must log in or register to reply here.
Top Bottom