Anyone with pics on Octopus removal?

Hi I have a 98 wr and I am interested in removing the Octopus I saw the post in the technical section but would like to see some pics on how to do it, at least a picture of what one looks like done. if anyone could help I would appreciate it, Thanks

if someone can find the old picture gallery i had about 6 photo's up of which one had a picture that had the carb in it.

anyone help here?



To see what it is like, you just havae to picture it w/ it removed.

IMHO, It is well worth it to get it off of there.

Just something else to go wrong.

I'll take a picture of mine and post it here tonight after work....

Bonzai :)

I have a pic here:


Sorry, didn't mean to hole shot you Kaze :)

[ November 28, 2001: Message edited by: Heywood ]

Heywood thanks for the pic. One question though the hot start line on my bike branches into a T do I just need to run one line to the hot start button. Thanks


Thanks for taking the time. Now I also need to add the PAJ #100 and the start jet #65 after removing the vacuum module. Is this still correct? Again thanks for your time.

Pete :)

Fun Pete,

Yes, you need the two YZ air jets.

That's Cool Heywood.....I came home early tonight to download the photo to Photopoint and the wife rand off to church with the camera.....Thanks for the back up.... :D

WRFUN: Careful with that 100 PJ if your not planning to go up on the PJ as well. If your're still stock at 42 and go up on the pilot alone you will run lean...I would recommend two things..#1 go down with the SJ as outlined. Without the ACV the SJ is way too rich. You'll know it by the black smoke when you twist the throttle with the choke open.

Try your bike with the stock settings first 42PJ /75 PAJ and see what it may be ok.

If it pops a little on decel the go 1/4 turn out on the PS, but no more than 1/2 turn. at 1/2 turn it still pops, then go to the 100 PAJ and a 48 PJ.

Remember that removing the ACV stops the automatic air regulation feature of the device and now you have to set it up manually (More Efficient), The trick is to be patient and don't change more than 1 combination at a time. At first I was highly nervous about messing with the jetting and needle changes, many people here on this forum are very good, and it has made it fun and a challenge to get it right.

Taffy and JD have posted many good and helpful charts in the Jetting Que.

Good Luck

Bonzai :)


[ November 28, 2001: Message edited by: YAMAKAZE ]


Thanks for the advice. I plan on doing the YZ timing MOD at the same time and JD suggested I start with Bill's( Discussion Moderator ) Carb settings as my starting bench mark. EKP #4, 50PJ, 175MJ, 100PAJ, 65SJ(thanks JD and Bill)Bill thanks for the Kouba T-Handle advice. YAMAKAZE thanks for hooking me up with MX-Tuner, when the snow hits guess were my forks are going. You VET's have been great. :D Thanks !!!

Pete :)


Man..... I think I am screwed for deoctopussing. My 99 (EURO) model carb doesnt look ANYTHING like that, even accounting for mine still being 'octopussed' and the photo deoctopussed.

Where is the ACV body on the carb photo above ?? Mine is positioned approx where the yellow mark is about 1/2-1 inch under the choke.


I have the hot start hose splitting into 2, one goes to the ACV, one to the manifold. So far so good, my hot start would look like the picture too if I de-octopussed, but where is the hole on the ACV from the hot start T that needs to be plugged ??


HOWEVER I have two other pipes attached to the ACV. One pipe goes to the carb just above the choke connector. The other pipe goes to the intake area of the carb. If I pull these pipes Ihvae to plug EACH END. So if I remove all of these pipes from the ACV + the hot start connection I have 5 holes to plug.

1 hot start connector

2 on the acv itself

1 somehere near the choke

1 somehere near the carb air intake!!

On the picture it looks like there are only 2 holes that have been plugged (+1 for hotstart which isn't visble ?)

Am I on drugs or does someone else out there agree with me for a 99?

I know a photo would help, I'm working on it !!

What I'm guessing is that I should just yank ALL of the hoses off of that thing and just plug ALL 5 of the holes. next problem is I have run ragged trying to find plugs. Noone stocks anything remotely like it. I have a few dollars to send to anyone who would be willing to send me the right caps.

Missle Man,

First off, the Octopus in the picture has been removed. It did go where yours is.

When I did mine, all I needed extra was the two rubber plugs. Whatever you need to do this mod, you have in front of you. The "T" connector is not needed at all. Use the longest hose you have to connect to the nipple at the intake manifold (between carb and cylinder). The other end of this longest hose connects to your hot start. You will have the two brass nipples on the carb body to plug with the rubber caps. I found the rubber caps at an automotive parts place.

Something else that is missing in the picture is the mounting bracket that the ACV attaches to. I left this bracket in place until I found a suitable length nut and bolt to remove this bracket. Once you pull the ACV, you should understand what I am talking about.

IF YOU ARE UNSURE about this procedure, mark all your connections prior to disassembly. This way you can slap it all back together.

Dude, you are doing fine. We ALL will make sure this comes out "FAT" (that would be "Fat, Dumb & Happy!! :) )

CLICK!!!!!!! as the light bulb indicates....I have just realised that you actually REMOVE THE WHOLE OCTOPUS BODY INCLUDING THE PIPES. DOH!!!!

I was only going to remove the PIPES. My procedure would have left the OCTOPUS body on the carb and I would have been blocking off the remaining exposed tube openings, hence my 5 blocks, 3 on the Octopus body and 2 on the body.

Tell me I'm right !

Oh, I am a happy man if this is correct cos I have been going bats h i t trying to figure this out. Sometimes even the simplest things are a challenge.

Something learnt today !!

Thanks to all, esp Taffy who got the brunt of my questions as I know he has an identical bike...

I think I'll have one more celebratory beer now and then hit the road...


[ November 29, 2001: Message edited by: The Missile ]


Remove the WHOLE THING, take it to the nearest precipace overlooking the bottomless gorge, and THROW IT IN!!


You are CORRECT! Give that Man a cigar!!

As a side note, the two YZF air jets are installed to mimic the YZF carb in lieu of the octopus. If the stock YZF jetting is lean...your carb may be lean. Someone mentioned earlier about the air jets too lean...

[ November 29, 2001: Message edited by: NH Kevin ]

SUCCESS! Gone, removed, oiked off, slam name it, its outa there ! Took all of 5 minutes.

I finally EVEN found some plugs to block off the holes .

On jetting.....I am running taff inspired jetting so I dont think normal rules apply!!!

No apj, maj180, mj155, PJ 38, PAJ/Screw 65. This thing really hauls ass. I am struggling with a very slight bog on 'take off', taffy assures me its a lean condition from not having the apj hooked up so I am lowering progresively my PAJ setting to richen it slightly. According to taff the apj normally squirts fuel down the carb throat to catch up with the air so you dont get an over-lean condition causing a lean 'bog': air moves faster than fuel as it is heavy/dense so you have to compensate for that as it rushes into the cyclinder.

It starts cold first/second kick in tests I did last night & this morning, it pops slightly on decel and all round just goes like a 'raped ape' to quote someone from this site.

I am sure there is still a little fiddling around to do (main jet maj to bring down) but I'm almost there.

guys, im from the Philippines and have a Stroker KLX 307, i am new to the WR 400F, mine is 1998 and purchased in the US. I got the YZ timing, Titanium Headpipe, YZF muffler. My question is the de-octopussing, whats the benefit? could i do it without jetting changes, i cant find the jets in the philippines. I cant understand some of the APJ, PAJ and stuff like that. Sorry for the ignorance. Thanks

Paul Azcona


Hey James Dean

I was follow your jetting and felt good on my 00 WR 400,but I have not trim the carb.pump rod or time it to 0.5 sec.yet.And still WR timing with Yosh.exhaust.

What is a de-octopus ?I have not done this yet.

plus I read on the other post on problem with jetting, it have some jetting refer to PJ and SJ.

This is my Jetting

Main jet 175

needle EKP #4

pilot air jet 100

1 turn on fuel screw

Now ,my pilot jet is 48 ,What is SJ ?

Am I on the right track ?

My bike start fine when cold,but when hot it unpreditable.sometime 2 kicks and sometime 6-7 kicks !.This never happen when I ride MX,any time on wood racing it always give me hard time.



The octopus has been discussed at length here and on the WR250 forum. The understanding is it is used for starting the bike, and that is it (the YZF DOES NOT have this thing). This octopus also regulates fuel/air on deceleration. It DOES interfere with properly setting your fuel screw. This is the screw underneath the carb.

The octopus vacuum lines have a very real potential of getting pulled out, allowing a direct shot (of whatever you are riding in) into your carb and engine.

To MIMIC the YZF carb, a new pilot jet and pilot air jet are installed. Now, whether or not these are actual required jet changes are only known to our carb guru's JD, Clark Mason, Taffy, Hick and...???

The APJ is your Accelerator Pump Jet. That is not involved w/ this mod, but you CAN modify this make your bike operate more efficiently.

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