Technical Discussion Topics related to Technical Issues

hesitation after installing dyno jet kit and k&n

Old 01-09-2005, 04:49 PM
  #2  
Senior Member
Back Marker
 
caffeineracer's Avatar
 
Join Date: Dec 2004
Location: Los Angeles, California, Canyons = SMM's, ACH,
Posts: 147
caffeineracer
Shimming the jet needles .040" - .060" should help, I had to do this when I fitted a K&N and I'm using stock pipes with the TPS adjusted @ 430.

The K&N flows so much more than stock you need to shim the needles even on an otherwise stock bike. If your 'kit needles' have clip adjustment raise them, otherwise you can shim them with small washers avilable at Radio Shack.

~Jeffers
caffeineracer is offline  
Old 01-09-2005, 06:10 PM
  #5  
Sprung
World Champion
 
Hawkrider's Avatar
 
Join Date: Dec 2004
Location: Fulton, MO
Posts: 105,285
Hawkrider will become famous soon enoughHawkrider will become famous soon enough
First I'll reply with "Don't remove the resistor in the plug wire!" It will do you no good. The resistor is there to reduce frequency radiated by the wires which interrupts some radio frequencies. Do you really want folks fu&king with their radios when you are riding around them? I think not.

Now, sorry for the temporary threadjack. Back to the jettting: I need to know if you have a Factory Jet Kit or a Dynojet Jet kit. I can help you out with either, but will give you a good baseline setup with the Factory kit.
Hawkrider is offline  
Old 01-10-2005, 01:39 PM
  #7  
Sprung
World Champion
 
Hawkrider's Avatar
 
Join Date: Dec 2004
Location: Fulton, MO
Posts: 105,285
Hawkrider will become famous soon enoughHawkrider will become famous soon enough
Re: hesitation after installing dyno jet kit and k&n

Well, crap. If the RLZ archives were available I could refer to an old post, but alas they are gone forever.

Okay, we'll do this the old fashioned way. Take the bike out for a spin. Pull the choke out just a bit while riding and see if the stumble goes away. This will tell us if you're rich or lean. If it gets better choked then you're lean. Try different amounts of choke.

Also, does it do it at low rpm w/light throttle?

Main jet sizes sound about right. I assume you have good top end power?

What are your mixture screw settings?

One more question: What exhaust are you running, and what is your elevation? Okay, that's two questions.
Hawkrider is offline  
Old 01-11-2005, 11:31 AM
  #10  
Senior Member
SuperSport
 
Join Date: Dec 2004
Location: Nananimo, B.C.
Posts: 764
NOrrTH is an unknown quantity at this point
Re: hesitation after installing dyno jet kit and k&n

This is good stuff as I'm about to go through the same thing with my bike. K&N should arrive any day then I'm gonna order the Dynojet kit
NOrrTH is offline  
Old 01-11-2005, 01:30 PM
  #11  
Sprung
World Champion
 
Hawkrider's Avatar
 
Join Date: Dec 2004
Location: Fulton, MO
Posts: 105,285
Hawkrider will become famous soon enoughHawkrider will become famous soon enough
I don't recommend the Dynojet. It's more difficult to tune than Factory, and you have to drill the slides, which makes it harder to go back to stock.

Okay, back to the problem at hand...

The stumble is from the rich idle, same with the hunting idle. I suggest adjusting the mixture screws to 1.75 turns out and see how that works. Leave the pilot jets stock #45. Also, while you have the carbs off (because that's what it takes to adjust the mixture screws - they're "D" shaped BTW) go ahead and raise the needles so that the clip is in the middle (3rd) position. This will help make up for some of the loss of fuel around 2-3k from the idle screw adjustment.

Wiley Co are very free flowing pipes, but it's not a full system and doesn't warrant going to a #50 pilot. Also, the BMC has different flow characteristics than the K&N. The BMC is actually a little more restrictive, but not by much. I hear it's easier to tune the BMC.
Hawkrider is offline  
Old 01-12-2005, 12:49 PM
  #13  
Sprung
World Champion
 
Hawkrider's Avatar
 
Join Date: Dec 2004
Location: Fulton, MO
Posts: 105,285
Hawkrider will become famous soon enoughHawkrider will become famous soon enough
430-480 ohms. Some can't get that low without tearing the TPS open and bending the little tab over. If you do that, be VERY careful you don't break the thing. It's quite expensive. You can also take out the metal inserts in the elongated holes to give you more adjustment range.
Hawkrider is offline  
Old 01-14-2005, 08:42 AM
  #16  
Sprung
World Champion
 
Hawkrider's Avatar
 
Join Date: Dec 2004
Location: Fulton, MO
Posts: 105,285
Hawkrider will become famous soon enoughHawkrider will become famous soon enough
Actually the hunting idle will get worse as the bike warms if it's running rich. If this happens, give the mixture screws another 1/4 turn in.
Hawkrider is offline  
Old 01-19-2005, 05:30 PM
  #18  
Sprung
World Champion
 
Hawkrider's Avatar
 
Join Date: Dec 2004
Location: Fulton, MO
Posts: 105,285
Hawkrider will become famous soon enoughHawkrider will become famous soon enough
I think what's happening is you are fouling plugs really bad and that is causing your stalling. I would go in another 1/4 turn and raise your idle just a tad. By backfiring, do you mean through the exhaust or through the carbs? Try cleaning the plugs as well. Try this, start the bike, let it idle until it dies, then pull the plugs. I'll bet you a 6-pack they are black as coal. Do this before you adjust anything else.
Hawkrider is offline  
Old 01-20-2005, 06:46 AM
  #20  
Sprung
World Champion
 
Hawkrider's Avatar
 
Join Date: Dec 2004
Location: Fulton, MO
Posts: 105,285
Hawkrider will become famous soon enoughHawkrider will become famous soon enough
So when you pulled the plugs last time were they black?
Hawkrider is offline  
Old 01-20-2005, 07:55 AM
  #21  
Senior Member
Back Marker
 
Rollingalong's Avatar
 
Join Date: Oct 2004
Posts: 205
Rollingalong
Re: hesitation after installing dyno jet kit and k&n

Quote:

am sorry i just have little probs to work out sorry if i am being a pest
if i get mine fixed right then i can fix my brothers too


Hey man , thats what this place is for . Not to worry there .

Was the TPS the main problem ?
Rollingalong is offline  
Old 01-26-2005, 06:23 PM
  #24  
Moderator
MotoGP
 
superbling's Avatar
 
Join Date: Dec 2004
Location: South Texas
Posts: 2,553
superbling is on a distinguished road
Re: hesitation after installing dyno jet kit and k&n

Disregard, I thought you had it solved. DOh!
superbling is offline  
Old 01-31-2005, 05:00 AM
  #26  
Senior Member
Back Marker
 
Rollingalong's Avatar
 
Join Date: Oct 2004
Posts: 205
Rollingalong
Re: hesitation after installing dyno jet kit and k&n

00996rider ,

I would go back and make certain the rubber diaphrams are under the carb caps correctly and then check to see if the rubber seal ring between the carb and air box is wadded up and leaking air .

Sounds like the diaphram though .

To ease placing the cap on top of the carb and geting the O.D of the diaphram in proper position, use a finger to lift the slide a bit . That takes some of the stretch from the rubber .

Without putting any of the three screws in lay the cap on the carb and hold down . Look all the way around it and you should not see any of the diaphram holding the cap up .

EDIT :

While in there make sure there is a small washer on top of the needles c-clip and after reinstalling the needle holder there should be a large washer under the slide spring . It's used as a seat for the main spring . It will not cause your problem but it should be there .
Rollingalong is offline  
Old 02-09-2005, 07:13 PM
  #28  
Moderator
MotoGP
 
superbling's Avatar
 
Join Date: Dec 2004
Location: South Texas
Posts: 2,553
superbling is on a distinguished road
Re: hesitation after installing dyno jet kit and k&n

OK, I've been following this thread quite closely as I was having the same problem/condition; that of poor running at steady throttle or slow roll on in the the 2000-3500 rpm range. Basically engine would surge and sputter, carb spits, and sounded like it was running out of gas. Idle and ran great everywhere else. Custom fram filter/2bros hi-mounts. Condition is better with choke or with stock pipes.

First since it didn't cost anything, I did a carb sync and reset idle speed. Helped overall running/idling but didn't solve it. Next, I tried the tps/shim the needles mods (cost $1 or so for the washers). This helped much more but didn't eliminate the condition.

So, I broke down and ordered up a Dyno-jet kit ($$). After reading all the paperwork, I crawled into the carbs to find that my used 98 has all ready been dyno-jetted! Not only that, it's setup correct according to the instructions (180/185, needles on 4, 2&1/2 turns out). Ahh, crap.

Reading the troubleshooting section, it mentions altering the needle position "up". So I did, going from 4th to 3rd. Seemed a little better. Went from 3rd to 2nd, bike ran worse (still talking 2-3500 range). I was bummed about all this and then it dawned on me: I was going "down" numerically but "up" on the needle (DOH!). Instructions are meant numerically so I then went to the #5 position.

Bike runs like a perverbial top! Me very happy.
superbling is offline  

Thread Tools
Search this Thread
Quick Reply: hesitation after installing dyno jet kit and k&n


Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service

© 2019 MH Sub I, LLC dba Internet Brands

We are a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for us to earn fees by linking to Amazon.com and affiliated sites.