Taffy or LarryCo!! I need your help please.



37 replies to this topic
  • live_to_ride

Posted June 19, 2003 - 06:53 PM

#1

I am getting really frusterated with this jetting stuff.
Here is what I starter with:

Almost stock wr 450- 155 mj, 70 paj, 45 pj, stock needle stock clip position, 2 turns on fs. The main problems were a really bad bog and low sleepy power.

Here is where I'm at now:

Almost stock yz jets and yz cam- 155 mj, yz needle middle clip, 100 paj, 42 pj, 1.5 turns on the fs. The bog is almost gone but now it has a really hard time starting with the button and still seems low on power. Starting with the button was fine until I put the cam in. It seems rich when I rev it up to 5-6k in neutral, but I really don't know. I was just going by the way it smelled and assumed that the sputtering meant rich. I tried leaning the needle one clip to cure that, but then the bog came back.

I'm looking for a jetting setup that is good from 4,500 feet to 10,000 feet above sea level. If that can't be done, then how about one setup for 4500 feet, and one for 6 to 10k feet. No bog, good power, and easy starting like the wr jetting had. I have looked at recommended jetting for this altitude, but they always seem to have a 160 maj. I'm stuck with a 200. I guess that would just make it leaner on the very top?

I may need to redo the whole thing. What should I get for jets/needle?
Main jet
Main air jet will be 200
Needle/position
Pilot jet
Pilot air jet
Starter jet
Leak jet
BTW- what is a APJ? Does that stand for acc pump jet? Same as a leak jet?

Thanks a lot for your help.

Chris :)

  • Taffy

Posted June 19, 2003 - 10:55 PM

#2

when i go to help someone i'm not normally thinking of a complete re-education programme!

if it isn't you LTR, it was someone else who put up YZ needle and i've said it before and i'll say it again. I DON'T KNOW WHAT THE STANDARD PHUQING YZ NEEDLE IS!

i'm not a parts department. the jetting you've moved to isn't anything that i recommend so what you're saying here is that now i'm in the [@#$%&*!] coz i went up the wrong creek come and get me.

going by the smell :)

revving it in nuetral :D

the #200 MAJ makes the bike leaner, a #160 makes it richer. but these are at revs that no mere mortal should be looking at. 9-11,000 revs!

the APJ is the accelerator pump jet, correct, however there is a leak jet within the APJ that is a seperate issue.

several people with 450's have asked for jetting assistance. but the needle code was so far away from anything that the first 5 years of production have used that i asked them to pull the emulsion tube/atomizer out and look for a code on the side of this before we venture any further.

TO DATE NOT ONE RIDER HAS DONE THIS.

as for the cams a small 'rocking' of the cam or even a different profile won't make any difference that we can't deal with.

when a needle code is so far away i'm at least asking why but as usual apathy rules.

as we say in sport "HOW MUCH DO YOU WANT IT!"

Taffy

  • Machster

Posted June 20, 2003 - 04:22 AM

#3

Ok..I am about ready to crate my flippin 450 up and ship it across the pond to Taffy, so he can finally have all the info he needs. For whatever reason, we keep going round and round on this issue, I being one of the unfortunate few in the beginning, who got his ass completly flamed for asking questions. Well..I have come to this conclusion:Not all of the answers are in the holy grail we call the jetting qs thread. As a matter of fact, for us 450 owners, it helps very little. The changes that were made to the '03 carb are so dramatic, with needle code changes, different apj setup, lack of maj info, can you blame the newbies for asking the questions they do?. I must say that I have recieved wonderful information from many in here, some willing to have me come to their house with my bike to help me!. So on that note...why is my bike running so damn good with a 178 mj and a 42 pilot per fmf specs?. stock wr needle obdut 5th clip 1 1/2 turns. I would love to run taffs suggs on this, but with no apj(S) on the market to speak of, where do I go?. I am leaving in an hour to do some testing myself, and I will report back on what I find :) :D

  • LarryCO

Posted June 20, 2003 - 05:32 AM

#4

Chris,
I was totally surprised on just HOW drastic a change was made between the 400/426's and the new 450's in terms of jetting. Without really knowing anything about the 450, and assuming they still had the same carb, I was floored when folks started talking about the jetting they were running.

So, given that, I'm admittedly pretty useless to you in terms of spitting out some magic formula for you to throw in and run with. I CAN say that if I were you, I'd throw in what you've found to work best so far and just start doing lots O testing, focusing on one circuit at a time. Lots of folks start with the pilot circuit...but I've always been a proponent of starting on the top end and then working my way down...since the MJ controls such a wide range. You'll probably find though that you'll have to go back and change things that you thought were set fine, in order to fix other problems...but that's just the way it works.

If you have any questions in terms of what tests to run to help figure out what's going on with your bike, you might check out a post I put out there called "High altitude jetting" or something like that. I think I remember summarizing the Patrick Burns jetting guide into about 8 different tests you can run to help get your jetting dialed in. It's certainly not the "savior" of jetting or anything, but it might be a good start. You might also consider buying the JD jetting spreadsheet from the TT store...it'll graphically show you affects of changing certain jets from a baseline that you put in there. Found it helpful when I was learning what the heck all these damn jets were doing to my bike... :)

Be patient young skywalker...doing lots of testing will eventually get your bike dialed in...not to mention, having you learn a great deal about your bike in the process.

Good luck...and dont hesitate to ask questions when you have 'em. That's all part of the process...

Larry

  • James_Dean

Posted June 20, 2003 - 12:58 PM

#5

Chris,

Put the YZ needle 1 or 2 clips leaner, replace the pilot air jet with the stock #70 and keep the #42 pilot jet with #155 main jet. About 1 1/2 - 2 turns on the fuel screw.

You made too many changes at once and the needle is critical to good jetting.

Post your results, it should be improved and the altitudes should not be a problem.
--Don't test your bike on a stand, go ride it and evaluate under real-world conditions. A bog can happen on a stand and not occur at all while you ride. The bike needs to be ridden both easy and hard to be a valid test.

James

  • Indy_WR450

Posted June 20, 2003 - 02:09 PM

#6

I have been saying the same thing. My bike likes a big pilot and PAJ as well as a richer larger taper needle and smaller main.
You cant debate the trottle response that you feel. The 426 and 400 carbs are very different indeed. We need to start a 450 jetting post only. :)

  • live_to_ride

Posted June 20, 2003 - 04:39 PM

#7



several people with 450's have asked for jetting assistance. but the needle code was so far away from anything that the first 5 years of production have used that i asked them to pull the emulsion tube/atomizer out and look for a code on the side of this before we venture any further.

TO DATE NOT ONE RIDER HAS DONE THIS.


Taffy




Taffy- what is this tube, where is it, and how do I get it out?



the APJ is the accelerator pump jet, correct, however there is a leak jet within the APJ that is a seperate issue.


Taffy




What is the difference between the two, and where is this apj?



going by the smell :)

revving it in nuetral :D

Taffy




Going by the smell is the only way I know how to tell if it is rich or lean. Give me a better way and I'll do it.

As for revving it in neutral, so far the bog has been EXACTLY the same (as far as I can tell) in neutral and riding. It just took longer to die when riding after snapping the throttle open.

  • live_to_ride

Posted June 20, 2003 - 04:46 PM

#8

Chris,

Put the YZ needle 1 or 2 clips leaner, replace the pilot air jet with the stock #70 and keep the #42 pilot jet with #155 main jet. About 1 1/2 - 2 turns on the fuel screw.

You made too many changes at once and the needle is critical to good jetting.

Post your results, it should be improved and the altitudes should not be a problem.
--Don't test your bike on a stand, go ride it and evaluate under real-world conditions. A bog can happen on a stand and not occur at all while you ride. The bike needs to be ridden both easy and hard to be a valid test.

James


I tried moving the clip one position leaner. The off idle bog was terrible again. I put it RIGHT back and it is much better.

I tried the 40 pj with the 70 paj and wr needle and it woudln't run worth a crap until the fs was 3.5 or more turns out. Will it work better with the yz needle since the straight is thinner/richer? :)

As for the bog happening while sitting but not while riding, I haven't seen this at all. So far the bog in neutral mimics the bog while riding really well. I realize this may change as my jetting does though.

  • blackie

Posted June 20, 2003 - 04:55 PM

#9

Chris,

Have you ever thought about selling the bike and buying a YZ? It's a lot easier to put a light on a bike then change the engine. Oh... wait, you wouldn't have the magic start button.. LOL

Just joking.... When are we going riding again??? Do you think your bike will be back together for the weekend?

john
718-9380

  • live_to_ride

Posted June 20, 2003 - 05:00 PM

#10

Chris,
I'd throw in what you've found to work best so far and just start doing lots O testing, focusing on one circuit at a time.

Be patient young skywalker...doing lots of testing will eventually get your bike dialed in...not to mention, having you learn a great deal about your bike in the process.

Good luck...and dont hesitate to ask questions when you have 'em. That's all part of the process...

Larry


So far the only tests I have done are:

1. snapping the throttle at low/mid rpm for the bog problem. I rode a yz 450, and this was much better than mine, so I switched partially to yz jetting. The bog is better, but starting with the button sucks.

2. Bringing the engine to 5-6k revs and smelling and listening to the exhaust. With the yz jetting it seems (I think) way rich. The exhaust smells nasty and it sputters a lot. I tried leaning the needle one position and the bog came back. I was mad about the bog so I don't even remember if that fixed the richness.

3. Trying different pilot and pilot air jets to try and fix the starting issue. It seemed to get a little better when I put the 42 pj in place of the 45. Maybe I'll try the 40 again. The 40 didn't work at all with the 70 paj and wr needle. I definitely noticed that the idle was much richer when I put the 100 paj and yz needle in.


What other tests can I do?

Thanks to everyone for the help! :)

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  • live_to_ride

Posted June 20, 2003 - 05:03 PM

#11

Chris,

Have you ever thought about selling the bike and buying a YZ? It's a lot easier to put a light on a bike then change the engine. Oh... wait, you wouldn't have the magic start button.. LOL

Just joking.... When are we going riding again??? Do you think your bike will be back together for the weekend?

john
718-9380


Hey John! I'm riding the standsburry trail with eric tomorrow, and you're welcome to come! I'd also like to get out on sunday. You up for riding sunday? :)

  • blackie

Posted June 20, 2003 - 05:38 PM

#12

Chris,

Sunday would be a lot easier then Saturday for me. How about earlier in the morning at 5-Mile before all of the ATVs are on the scene??

John

  • live_to_ride

Posted June 20, 2003 - 05:57 PM

#13

ROCK ON JOHN!!!!!!!!!!!!!! That makes me way happy. I really wanted to ride sunday too. I'm gonna put some fresh rubbers on the bike saturday evening and I want to see how they do. :) :D :D

:D

  • live_to_ride

Posted June 20, 2003 - 05:59 PM

#14

I thought of another question. How the heck do I tell if the main is too rich or lean? Thanks again! :)

  • Guest_Guest_*

Posted June 20, 2003 - 06:44 PM

#15

I thought of another question. How the heck do I tell if the main is too rich or lean? Thanks again! :D

WFO, I think :confused:I'm just learning myself :)

  • Taffy

Posted June 20, 2003 - 08:32 PM

#16

LTR

the emulsion tube/atomizer is the long tube that the main jet sits in the bottom of and the needle slides up and down the middle of.

there will be some writing on it some where that will tell us if you have the same ET as all the old models. if there is no writing try and measure the amount of tube that pokes up into the plenum (the bit you can see!).

at the moment though OB DUT is so far out the park i'm glad i'm sat down when i read it.

the 'T' is two 'fatter' than the widest used before! the euro WR's from '99 were supplied with the OB DXM needle so the big difference is the needle straight. so M, N, P, Q, R, S, T!!!!!that's a lot of needle width change!

the only time we worry about the needle straight is to start it, the first yard and decel when we hear back popping.

in jetting Qs i bored out the top end of my ET and i also bought an EMT needle in a quest to learn more.

so my conclusion is that you have a wider ET on the '03 450's.

it could even be a tuning tip if it is wider because both JD and i wanted our taper to start higher up the needle and yet the needle diameter has to be the right width for the ET.

now a wider ET would allow R, S and T needles AND still the correct gap twixt side of needle and hole.

if you don't follow this conversation just think of it like this;you have a needle with a taper, looking from the tip up if the needle were to get wider on the straight the taper would continue "up and out" to where the straight and the taper meet yes? the wider the needle, the higher the straight starts correct?

this is all great but in our ET's the less space down the side means less fuel for tickover. so we're forced to compromise.

in my "snap..." posts that nobody here knows about from when i VERY first tested, i carried the needle very high with the clip in #7 and was getting massive wheelies, monster arm ripping getaways only for the bike to die at mid revs coz the needle was about 6 clips to high for midrange.

i'm guessing this has got some of you totally confused but there will be others who have now learnt enough about jetting to say that they can follow what i'm saying here.

good luck!

Taffy

  • James_Dean

Posted June 20, 2003 - 09:06 PM

#17

I tried moving the clip one position leaner. The off idle bog was terrible again. I put it RIGHT back and it is much better.

I tried the 40 pj with the 70 paj and wr needle and it woudln't run worth a crap until the fs was 3.5 or more turns out. Will it work better with the yz needle since the straight is thinner/richer?

As for the bog happening while sitting but not while riding, I haven't seen this at all. So far the bog in neutral mimics the bog while riding really well. I realize this may change as my jetting does though.



Chris,

Ok, you're starting to give some useful background.

Running a 42PJ/70PAJ is richer than 42/100, yet you turned the fuel screw out to 3 1/2 turns with 42/70 and less with the 42/100. Doesn't make sense other than the YZ needle is richer.

Starting would usually be better with the 42/70. Your carb has a air bypass and the YZ does not. Using the #100 on a WR will be leaner than a YZ carb with a #100, this leads to using the 42/70 instead except when considering higher altitude riding. You were running a #45PJ before, so stay with what works (probably 45/100 or 42/70) and work with the fuel screw with the bike fully hot.

The YZ needle will richen idle slightly because of the needle diameter. About 3 steps-Q,R,S,T. Are looking at a NCVQ needle? Check the needle or receipt if you would please, even a part number.

Please understand that my suggestions are aimed at higher altitude riding and a little common sense. The needle and pilot jet setting should be a few steps leaner than the stock YZ settings. Try a #160 main also.

If the bog is excessive, check to make sure the accelerator pump is working/squirting and not clogged.

I have a YZ450F in my garage for tuning tomorrow and will be interested in your results.

Thanks,
James

  • sjw

Posted June 21, 2003 - 11:07 AM

#18

I agree someone needs to start a 450 jetting post.I dont know enough to start one.my bike still has stock jetting and Iknow it needs to be changed .HELP!!!!!

  • captain_S

Posted June 21, 2003 - 12:52 PM

#19

The best help you can get is to help your self by first having the courage to go out and try some different settings!,you can ask the guys here on this thread till you go blue in the face what is wrong with the bike but untill you try for your self you will never really be able to understand just what the guys that really do understand jetting are trying to tell you!,i am in no way trying to make you feel bad here because i was also in your position once too!.I dont in any way believe that i personally know everthing about jetting(i have been trying for well over 2years now to get my bike the way i would like it)but it takes time and knowledge,i have made so many mistakes with jetting in the past and i will probably make some more too,but dont let it faze you go out and try it,it is the only way to help yourself understand how jetting works,and with a bike so good but yet so fickle i think it will be the only way you will really get the most enjoyment from your machine,the whole reason i found TT was to help me to get my bike where i like it,and with out the help from other TTmembers,i would not be any where near what i am now,i read for months what folks were saying about jetting but it was not untill i tried to learn for myself did the advice and discussions really start to help me!,i would strongly advise you to try for your self what may or may not work,but at least then you will start to get some idea of what goes on,and that jetting is a very complex matter but when you learn a little more about it it does start to make sense!,go for it you will be glad that you did :)

  • live_to_ride

Posted June 21, 2003 - 02:02 PM

#20

I went riding today and found that it ran and started much better with the fuel screw at 3/4 turn out. The bog is slightly worse, but at least my button worked again. :D Now I'm pretty sure that the 40 needs to go back in. The main problem was the sputtering when I hold the throttle in one spot from just off idle to about 1/4 throttle. The low end is really not that great any more. I think that is because of the yz cam. I would discribe the low end power as "just enough". Mid and top are much improved though. One of the biggest differences is how snappy the bike is. I definitely like that. :D Another problem today was that I stalled it a lot more than normal.

I think the sputtering while cruising is because it is too rich. :)

Taffy- I understood what you were saying about the ET tube. I'm really busy tonight, but I should have time to get the tube out tomorrow. If I can't get it out, then I should at least be able to look at it. Perhaps I could get a long tapered rod and see how far it will go in, then measure that spot on the rod with a micrometer. I hope I can just see a number on the ET. I don't think it is meant to be taken out, but I'm just guessing there.

I think my biggest obstacle is going to be getting the jetting right from 1/2 to 3/4 throttle.

Thanks for the help! :D




 
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