Technical Discussion Topics related to Technical Issues

Jetting?

Old 06-23-2011, 11:01 AM
  #1  
Junior Member
Squid
Thread Starter
 
Join Date: Apr 2011
Location: Denver, CO
Posts: 25
Tinyhuge is on a distinguished road
Jetting?

So I've had my hawk about 3 months now. Snappy torque, great handling, I've completely fallen in love. Last weekend I rode from Denver to So Cal to visit family, and now I'm really in love with the beast. Unbelievable power. What was a quick takeoff in Denver is a monster power wheelie at sea level.

The original owner from Idaho put on a set of high mount Jardine pipes and I assume rejetted. I bought the bike from the 2nd owner who only put about 300 miles on the bike after moving to Denver from Idaho.

I'm pretty good mechanically, having rebuilt engines and other equivalent jobs, but am basically a newbie with carbs. Should I try and tackle this on my own? Any advice on doing this? I hate to miss out on any great riding weather but she deserves to run right...
Tinyhuge is offline  
Old 06-23-2011, 01:09 PM
  #2  
Banned
MotoGP
 
Join Date: Aug 2007
Location: Lake View Terrace, CA
Posts: 5,942
8541Hawk will become famous soon enough
First of all search is your friend..... it will save you a lot of time if you figure out how and when to use it....

Here is my take on the carbs:
https://www.superhawkforum.com/forum...-set-up-24769/

Though with all things YMMV
8541Hawk is offline  
Old 06-23-2011, 04:37 PM
  #3  
Senior Member
MotoGP
 
Join Date: May 2008
Location: San Clemente, CA
Posts: 3,447
VTRsurfer is on a distinguished road
If it ran well at sea level in SoCal, you're not too lean. Denver being the "Mile High City" would richen the air/fuel mixture noticeably.

So if it ran much better at sea level, you're more likely too rich at 5000 feet.

Mine has the occasional idling carb fart and stall at sea level, but runs great all through the rev range once above idle, power wheelies are common in 1st. Above 2000 feet the carb farts and stalling at idle disappear. I was just up to 6000 feet a couple of months ago for some twisties in the mountains east of San Diego, and I had all the power I needed and then some on that ride. Very little, if any loss of power at that altitude.

You can see what I've done to my carbs in my signature below. My mixture screws are 2 1/2 turns out. I initially set them at 2 3/4 turns out, but it wouldn't idle above 2000 feet with that setting... too rich.

Last edited by VTRsurfer; 06-23-2011 at 04:40 PM.
VTRsurfer is offline  
Old 06-23-2011, 05:42 PM
  #4  
Junior Member
Squid
Thread Starter
 
Join Date: Apr 2011
Location: Denver, CO
Posts: 25
Tinyhuge is on a distinguished road
Originally Posted by 8541Hawk View Post
First of all search is your friend..... it will save you a lot of time if you figure out how and when to use it....

Here is my take on the carbs:
https://www.superhawkforum.com/forum...-set-up-24769/

Though with all things YMMV
Big fan of the search function. I started reading up on the Superhawk about a month before I bought it, and this forum was by far the best source of information. A big thanks to everyone for sharing years of experience. Your carb setup article is the reason I'm probably going to give this a shot, so thank you in particular. I'll be back home soon and try to get the carbs out in the next couple weeks. I'm sure I'll be back with more specific questions at some point.
Tinyhuge is offline  
Old 06-23-2011, 05:51 PM
  #5  
Junior Member
Squid
Thread Starter
 
Join Date: Apr 2011
Location: Denver, CO
Posts: 25
Tinyhuge is on a distinguished road
Originally Posted by VTRsurfer View Post
If it ran well at sea level in SoCal, you're not too lean. Denver being the "Mile High City" would richen the air/fuel mixture noticeably.

So if it ran much better at sea level, you're more likely too rich at 5000 feet.

Mine has the occasional idling carb fart and stall at sea level, but runs great all through the rev range once above idle, power wheelies are common in 1st. Above 2000 feet the carb farts and stalling at idle disappear. I was just up to 6000 feet a couple of months ago for some twisties in the mountains east of San Diego, and I had all the power I needed and then some on that ride. Very little, if any loss of power at that altitude.

You can see what I've done to my carbs in my signature below. My mixture screws are 2 1/2 turns out. I initially set them at 2 3/4 turns out, but it wouldn't idle above 2000 feet with that setting... too rich.
Those were my thoughts. Add air to the mix it runs great, take air away it loses power, must be running lean at home. I usually run at about 5300 feet, but when I go out to play in the rockies I regularly get up to 12000. Any thoughts on where I should set up initially?
Tinyhuge is offline  
Old 06-23-2011, 06:43 PM
  #6  
Senior Member
MotoGP
 
Join Date: May 2008
Location: San Clemente, CA
Posts: 3,447
VTRsurfer is on a distinguished road
Originally Posted by Tinyhuge View Post
Those were my thoughts. Add air to the mix it runs great, take air away it loses power, must be running lean at home. I usually run at about 5300 feet, but when I go out to play in the rockies I regularly get up to 12000. Any thoughts on where I should set up initially?
You'd be running more rich at altitude. The only way to avoid that is to get a bike with fuel injection. It's the lower air pressure that affects the operation of the carbs, plus lower oxygen content in the air.

12,000 feet? I've hiked up to 14,505', but the highest I've driven was 11,000' over Red Mountain Pass in the San Juans on several occasions, and that was in a fuel injected rental car.

All through the '70s I skied at Mommoth Mountain, and almost all the cars had carburetors. Cars that ran fine in SoCal would spew black smoke driving at 8000' in the town of Mammoth Lakes.

Last edited by VTRsurfer; 06-23-2011 at 06:47 PM.
VTRsurfer is offline  
Old 06-24-2011, 09:37 AM
  #7  
Junior Member
Squid
Thread Starter
 
Join Date: Apr 2011
Location: Denver, CO
Posts: 25
Tinyhuge is on a distinguished road
Whoops had a brain fart last night to go with my carb farts lol. Meant to say rich, not lean.
Tinyhuge is offline  
Old 06-24-2011, 09:57 AM
  #8  
Senior Member
Superstock
 
Join Date: Jul 2007
Location: Los Angeles & Winston Salem
Posts: 430
speedkelly@aol.com is on a distinguished road
12,000 feet? I've hiked up to 14,505',



Sounds like someone hiked Mt Whitney? I've done that hike, camped at the upper campground. Thats a pretty amazing view from the top huh!

Ok back to the subject jetting. I have pulled my carbs three times now to just adjust the mixture screws. Anyone who starts messing around with the jetting on these bikes in going to end up being very proficient at carb removal real quick! Good luck
speedkelly@aol.com is offline  
Old 06-24-2011, 12:53 PM
  #9  
Senior Member
MotoGP
 
Join Date: May 2008
Location: San Clemente, CA
Posts: 3,447
VTRsurfer is on a distinguished road
Originally Posted by [email protected] View Post
12,000 feet? I've hiked up to 14,505',


Sounds like someone hiked Mt Whitney? I've done that hike, camped at the upper campground. Thats a pretty amazing view from the top huh!
My wife dragged me up the trail in the mid '90s, a one day hike up and down. It was only 14,496' then though. I think with GPS or whatever they've gotten more accurate elevations in recent years.

And my wife's done it numerous times, including on skis and climbing the East Buttress. She lived in Bishop for several years.
VTRsurfer is offline  
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
Galaxieman
Technical Discussion
3
05-07-2007 06:45 PM
FRANKSVTR
Modifications - Performance
2
03-31-2007 05:12 PM
cliby
Modifications - Performance
10
03-30-2007 11:57 PM
redlinetech
Modifications - Performance
8
03-16-2007 04:34 PM
Shawn Torpey
Technical Discussion
4
03-09-2007 08:54 PM


Thread Tools
Search this Thread
Quick Reply: Jetting?


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.

All times are GMT -7. The time now is 09:55 AM.


© 2019 MH Sub I, LLC dba Internet Brands