Jetting?
#1
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...
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...
#2
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
Here is my take on the carbs:
https://www.superhawkforum.com/forum...-set-up-24769/
Though with all things YMMV
#3
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.
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.
#4
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
Here is my take on the carbs:
https://www.superhawkforum.com/forum...-set-up-24769/
Though with all things YMMV
#5
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.
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.
#6
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?
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.
#8
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
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
#9
And my wife's done it numerous times, including on skis and climbing the East Buttress. She lived in Bishop for several years.
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