Exhaust ID Help

[jimspac]

Eric, I would like to buy #3

 

[Up-tite]

First pipe is like mine on my other 86 400 XC motor, not a stock pipe though. Its an aftermarket pipe, not sure who made them it has no name on it also


View attachment 59172

From pic looks like HP Products if so I made it.
Welding some today.
Later George

 

[justintendo]

From pic looks like HP Products if so I made it.
Welding some today.
Later George

great to hear george. i would like to get a 87 430 pipe this fall or whenever they are available..
any ideas on pricing?
will these work with stock muffs or do you have any options available with better silencers?
thanks! love how these pipe take the upturn right out of the jug

 

[2premo]

First pipe is like mine on my other 86 400 XC motor, not a stock pipe though. Its an aftermarket pipe, not sure who made them it has no name on it also


View attachment 59172

looks familiar, same on my 430

 

[2premo]

From pic looks like HP Products if so I made it.
Welding some today.
Later George

so you made a few of mine including my mystery pipe

 

[Eric The Leg]

From pic looks like HP Products if so I made it.
Welding some today.
Later George

Any notes on how the performance differs from stock? Any Carb (or other) adjustments needed and/or notes on stock vs. Boysen vs. V-Force reeds with your pipes?

 

[justintendo]

ive never found any difference between the stock reeds and the boyesens..the v-force may be a different story as they are more than just replacement petals.

 

[Up-tite]

Performance is huge, power, torque, rideability.
Back then stock jetting was way off PJ usually ok maybe 1 size to big , needle jet usually to big , most needles ok,slide cutaway to rich , also main too rich.
With modern gas it's a big??????? Mexifornia gas is different than Texas gas is different than Pennsylvania gas. I jet for smooth transions,no flat spots, I want my plugs black and sooty but not wet. I don't want it to idle maybe 2 - 3 steps away before it quits,
Later George

 

[86 400 XC]

looks familiar, same on my 430



View attachment 59417

2premo how do find that pipe in the bottom end? Its terrible to me but has killer midrange and top end
I took my 400 pipe off the 86, it got wacked real bad. It has a big pinch in the first 90 coming off the motor and knocked other parts of the pipe into the frame. So i found another pipe to buy just like like yours and in the mean time i took the pipe of off my 87 WR with a 400.

Put it on my 430 in the 86 and what a dog it was, after an hour i gave up riding it was annoying .
Started to bog and 4 stroke on any tight climbs over stuff that you let off for a sec at low rpms. I came home and took a sawzall to it and removed 4 or so inches in front the cylinder.
Rode it today and what a good call on that mod, runs like a woods bike again. Slow rpm and shifting up another gear with smooth power and torque and low RPMs and zero sputter like the carb was way out..

before the chop












.



.
after





.


.



I have video of both days on the same hill and no other changes

 

[2premo]

funny but i recall a little loss on bottom but not enough to jet for
got an awesome mid and top but pulled hard enough to wheelie at low RPM's
odd results on your end
my 430 pulls so hard the pipe is more overkill than anything
these bikes are wicked out of the box and these mods are even more over the top
but,,,, what fun to blast past people at will

 

[86 400 XC]

Have a listen, so glad i made the change.

jump to the time in the title

View: https://www.youtube.com/watch?v=cJdoQMtxhww

View: https://www.youtube.com/watch?v=LofXbusgp-Q

 

[ajcmbrown]

Running a lot crisper in the lower rev range, what exactly was the mod you did to the pipe?

 

[86 400 XC]

The front loop in the pipe went from a large loop to a U bend.
Took 4" of pipe out of the loop, 2 cuts and 2 welds.



2primo's pic, same pipe

 

[ajcmbrown]

Nice, I still have my standard pipe so it may get this treatment.