Omg....... Jetting Help Please

[Punk'd]

This must be the 10th post iv had to made due to jetting. I just cant seem to get it dead on. Right now I am running a Full system Sparks.. Lid off, and a 185main jet. Iv been messing with the fuel/air screw so much that I dont even remember were it was stock. I need someones help really bad! I cant ride up my street past like 3rd gear (I live in the city) so I propped her up on a crate and ran threw all gears. It seems like its dead on but in the higher gears it shot fire and kinda makes a er er er noise in the higher rpms. Is there any way I can get this dead on..

Also when I first start it, it bogs and shuts off when I apply throttle, but after a min or so its fine. I guess its just warming up, but It never did that with the stock pipe.


Somebody please help:confused:

[450ss]

its probably not your mixture screws, set them back to stock and then go from there, but call sparks and they will tell you what to do free of charge you will probably be too high on your main by the time they set you all up and maybe your pilot is to small try a 48 maybe a 50 just call sparks and tell them what you have done and what its doing

[Punk'd]

Originally posted by 450ss
its probably not your mixture screws, set them back to stock and then go from there, but call sparks and they will tell you what to do free of charge you will probably be too high on your main by the time they set you all up and maybe your pilot is to small try a 48 maybe a 50 just call sparks and tell them what you have done and what its doing

Yeah, I called them and they said with lid off. 185main, and screw turned 2 turns out.

Two turns out bogged a little. So I turned it 2 1/2 turns and it seems to be running "ok" from what I can tell. To tell you the truth it sounds like I need a bigger pilot.

I put it in Nuetrual and reved it all the way really fast and then let off and it bogs just a little. Im pretty sure its a low rpm bog, but it only does that when I gun it fast..

[450ss]

do you have an aftermarket cdi or rev box

[chad502ex]

IMO you should not be dial'n in your engine with zero engine load propped up on skids. Find a dyno in your area to dial in your setup, or be at the Annual ATVRIDERS.com ride in PA for the Mobile Dyno setup to take a look for ya,...


hope this helps.

chad

[Punk'd]

Originally posted by 450ss
do you have an aftermarket cdi or rev box

Sure dont.

And yeah, I figured the same thing about proping it up.

[drider]

hey man seems like youre missing something. I'll tell you me exactg set up on my 450R with Sparks big core pipe.

No lid. stock air filter
185 main jet. HRC
HRC Needle 3rd clip.. thats all...!
Fired it up.. let it warm up (ofcourse)
then take it slow. thru 1st-5th.
let it idle.. see if it sounds to low. or to high....set to go . i didnt change no pilot or anything..

[Punk'd]

Originally posted by drider
hey man seems like youre missing something. I'll tell you me exactg set up on my 450R with Sparks big core pipe.

No lid. stock air filter
185 main jet. HRC
HRC Needle 3rd clip.. thats all...!
Fired it up.. let it warm up (ofcourse)
then take it slow. thru 1st-5th.
let it idle.. see if it sounds to low. or to high....set to go . i didnt change no pilot or anything..

Yeah, I just dont have the money for the HRC stuff at the moment. Or thats what id do:ermm:

[Pepto_Bismol]

Well,

Due to my own issues, I have done countless hours of research for jetting issues, (not quite the same problem as yours, but in doing research, I have seen your issue reported over and over).

I finally got mine dialed in.

From what your saying, you have a full Sparks system, and changed the main jet, but did not change the Needle. The needle helps controll the throttle response from approximately 1/4 to 3/4. IF you still have a stock needle, the taper is not correct for the type of setup you have. The very minimum, you would want to obtain the HCR needle. It's only about 20.00. An alternative may be to change the pilot jet itself, but there is no gaurentee this will completely help you. The best solution is to change the needle.

Your problem when you first open (blip) the throttle is most likey due to the fuel / air mixture screw, which affects idle. 2.5 to 3 turns out is usual. But I had to back mine in (to about 2 1/4) to get mine to idle right, and not "die" out when it was cold.

There was very little response to my questions I posted here (or at 450r.org), and not to knock anyone, but it seems that there are not too many people who actually know much about jetting, other than "what works for them".

Here is some helpful info:

http://www.rockymountainatv.org/pages/carb_jetting.htm

http://www.duncanracing.com/techfaq/Tech_keihin-carburetion-jetting.phtml

One thing that I did find, is that my altitude and temperature (about 105 degrees on average) made a huge impact on my jetting. Why me more than others? I don't know, other than the fact that even though it may be the same quad, build tolerance differences in parts can actually make that much of an impact.

For example, I used the jetting corrections suggested by the chart found here:

http://www.motocross.com/motoprof/moto/mcycle/carb101/carb101.html

And after I installed a smaller main jet, it ran perfect.

Hope this helps!

Pepto:cool:

P.S. In case your wondering, here is the link to my post about my jetting issue.

http://www.exriders.com/vbb/showthread.php?s=&threadid=175522

[Punk'd]

Originally posted by Pepto_Bismol
Well,

Due to my own issues, I have done countless hours of research for jetting issues, (not quite the same problem as yours, but in doing research, I have seen your issue reported over and over).

I finally got mine dialed in.

From what your saying, you have a full Sparks system, and changed the main jet, but did not change the Needle. The needle helps controll the throttle response from approximately 1/4 to 3/4. IF you still have a stock needle, the taper is not correct for the type of setup you have. The very minimum, you would want to obtain the HCR needle. It's only about 20.00. An alternative may be to change the pilot jet itself, but there is no gaurentee this will completely help you. The best solution is to change the needle.

Your problem when you first open (blip) the throttle is most likey due to the fuel / air mixture screw, which affects idle. 2.5 to 3 turns out is usual. But I had to back mine in (to about 2 1/4) to get mine to idle right, and not "die" out when it was cold.

There was very little response to my questions I posted here (or at 450r.org), and not to knock anyone, but it seems that there are not too many people who actually know much about jetting, other than "what works for them".

Here is some helpful info:

http://www.rockymountainatv.org/pages/carb_jetting.htm

http://www.duncanracing.com/techfaq/Tech_keihin-carburetion-jetting.phtml

One thing that I did find, is that my altitude and temperature (about 105 degrees on average) made a huge impact on my jetting. Why me more than others? I don't know, other than the fact that even though it may be the same quad, build tolerance differences in parts can actually make that much of an impact.

For example, I used the jetting corrections suggested by the chart found here:

http://www.motocross.com/motoprof/moto/mcycle/carb101/carb101.html

And after I installed a smaller main jet, it ran perfect.

Hope this helps!

Pepto:cool:

P.S. In case your wondering, here is the link to my post about my jetting issue.

http://www.exriders.com/vbb/showthread.php?s=&threadid=175522

Very helpful post. Thanks alot for posting that. Im going to go ahead and buy a HRC needle for $20 and this would clear my problem up correct? Also what clip would I run it on. 4th?

[chad502ex]

Originally posted by Pepto_Bismol


probally one of the most informative post in the history of jetting threads.


Very good. Thanks for your input.

chad

[the yazer]

ok ...... you NEED to get the hrc needle

[cals400ex]

i run the hrc needle in the 3rd clip position but some run it in the 4th

[Punk'd]

Does anyone know were I can buy the HRC needle? My dealer wants me to buy the whole kit and that isnt happening.

[honda7]

If you want to get it perfect take it to some body with a dyno it's the only way

[redrider05]

mine is 185 main three turns on air//fuel mixture and on the needle take it up one clip....and mine is smmmooth try that if u need something else to try

[cals400ex]

your dealer is a bunch of dill weeds though probably. give them this part number and order it up:

16201-NLZ-651


it probably won't be cheap. i am thinking these needles may be around $25 or so but could be wrong.