Modifications - Performance Discuss aftermarket and DIY performance modifications

jet questions

Thread Tools
 
Search this Thread
 
Old 03-03-2018, 09:06 PM
  #1  
Junior Member
Squid
Thread Starter
 
Thomas Gennaro Jeffers's Avatar
 
Join Date: Mar 2018
Posts: 3
Thomas Gennaro Jeffers is on a distinguished road
jet questions

Hey all,
ive got a '98 that i just installed Danmoto gp slip on's on, like 2 days ago. Now, i have a Dynojet kit in the mail to arrive this monday. My local shop wants an obscene amount of money to install it, but since i'm an aircraft mechanic by trade, i figured the headache would be worth the pennies saved by doing it myself.

Now i have never worked with carbureted machines in the past, but i understand the general principle and have watched a couple videos of people tearing these things apart. And its my understanding (correct me if i'm wrong), unlike a lot of the 4cyl bikes, a jet is basically required with these bikes after exhaust work since they run so lean.
My questions are:

-Should i worry about getting a dyno run in before and after
-is installing the kit, as is, as-per Dynokit's instructions sufficient? or will i have to play with the pilot jet some more
-what general settings would you recommend for an aftermarket exhaust similar to the one linked above?
-are there any little nuances or tips for removing the carbs on these bikes (except the obvious)
-what is the general opinion of kits (like the one linked above) for these bikes.
-is modding the airbox and replacing the stock filter worthwhile while i have the tank and everything off?


For infos sake im located in south jersey and to the best of my knowledge the bike has been un-bastardized and bone stock before i installed the exhaust.
Thomas Gennaro Jeffers is offline  
Old 03-03-2018, 11:17 PM
  #2  
Senior Member
Superstock
 
CaryDG's Avatar
 
Join Date: Sep 2013
Location: Costa Mesa, CA
Posts: 460
CaryDG is on a distinguished road
Use the Search function and all your questions will be answered. Welcome to Super Hawk Land.
CaryDG is offline  
Old 03-04-2018, 08:21 AM
  #3  
Moderator
MotoGP
 
Wolverine's Avatar
 
Join Date: Jul 2007
Location: Gettysburg, Pa
Posts: 5,071
Wolverine is on a distinguished road
https://www.superhawkforum.com/forum...-set-up-24769/
Wolverine is offline  
Old 03-04-2018, 03:11 PM
  #4  
Senior Member
Back Marker
 
Floyd's Avatar
 
Join Date: Sep 2017
Location: FL
Posts: 197
Floyd is on a distinguished road
I actually just took a dynojet kit off my bike because it ran so bad.
I went back to stock jets and needles and springs and it runs so smooth and nice now.
Floyd is offline  
Old 03-04-2018, 04:23 PM
  #5  
VTR virgin
Superstock
 
Cadbury64's Avatar
 
Join Date: Mar 2015
Location: Auckland, New Zealand
Posts: 446
Cadbury64 is on a distinguished road
I have gutted stock silencers (just a large bore perforated tube down the middle with packing outside that) and stock jetting on mine. Based on the plug appearance, this is just fine, and it runs well too. So before leaping into jetting land, why not check how your bike runs with the stock carbs?

If you do start to change the carbs, good scientific methodology would be to make a single change at a time.
Cadbury64 is offline  
Old 03-04-2018, 06:19 PM
  #6  
Junior Member
Squid
Thread Starter
 
Thomas Gennaro Jeffers's Avatar
 
Join Date: Mar 2018
Posts: 3
Thomas Gennaro Jeffers is on a distinguished road
Originally Posted by Cadbury64
I have gutted stock silencers (just a large bore perforated tube down the middle with packing outside that) and stock jetting on mine. Based on the plug appearance, this is just fine, and it runs well too. So before leaping into jetting land, why not check how your bike runs with the stock carbs?

If you do start to change the carbs, good scientific methodology would be to make a single change at a time.
Largely I just assumed it was going to need the jet, since the exhaust is a pretty substantial change over the stock cans. And it was my understanding the end bikes run lean-ish even in a stock setup. Searching through a couple other threads here (before I made my post) had some people saying they were running dangerously lean after installing a slip on.

That being said I rode the bike lightly today and it didn't feel bad, but I don't really trust my judgement in that regard being that I don't think I would really know the difference. The only thing I noticed was some light popping when rolling off the throttle in all rev ranges.
Thomas Gennaro Jeffers is offline  
Old 03-05-2018, 09:54 AM
  #7  
Banned
MotoGP
 
8541Hawk's Avatar
 
Join Date: Aug 2007
Location: Lake View Terrace, CA
Posts: 5,942
8541Hawk will become famous soon enough
Originally Posted by Thomas Gennaro Jeffers
Searching through a couple other threads here (before I made my post) had some people saying they were running dangerously lean after installing a slip on.
Well everyone has different experiences but I have never seen one go "dangerously lean" by just installing a set of slip-ons.
The bike will let you know by popping, banging and surging long before you go lean enough to cause damage.
Also one of the most common jetting "mistakes" on a VTR, IMHO, is going too rich.

So you will have no problems running the bike with slip-ons to see what, if any, jetting changes are needed.
Also as food for thought, I am running a bunch of bits on my engine including one of the better full exhaust systems and am running smaller than stock main jets.......
8541Hawk is offline  
Old 03-05-2018, 10:04 AM
  #8  
Junior Member
Squid
Thread Starter
 
Thomas Gennaro Jeffers's Avatar
 
Join Date: Mar 2018
Posts: 3
Thomas Gennaro Jeffers is on a distinguished road
Originally Posted by Cadbury64
I have gutted stock silencers (just a large bore perforated tube down the middle with packing outside that) and stock jetting on mine. Based on the plug appearance, this is just fine, and it runs well too. So before leaping into jetting land, why not check how your bike runs with the stock carbs?

If you do start to change the carbs, good scientific methodology would be to make a single change at a time.
Good info, thank you. It's popping a little on decel but that's about it, the ride is smooth
Thomas Gennaro Jeffers is offline  
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
clogee
Technical Discussion
2
05-01-2007 08:37 AM
Pookbe
General Discussion
3
04-25-2007 12:28 PM
Cleveland
Technical Discussion
8
03-27-2007 07:01 PM
Scumbag
General Discussion
4
03-15-2007 03:25 PM
99Hawkboy
General Discussion
2
07-19-2005 01:30 AM



Quick Reply: jet questions



All times are GMT -7. The time now is 01:27 PM.


Top

© 2024 MH Sub I, LLC dba Internet Brands



When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.