What jets to run?
01-19-2006, 02:07 PM
#1
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What jets to run?
We pulled the carbs apart on my friends VTR and found aftermarket Factory jets. The mains were 175 and 178. He's running two bros exhaust and an aftermarket filter. These seem a bit lean. What should he run and where should his clip be on the needle jet?
01-19-2006, 06:33 PM
#3
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Re: What jets to run?
You don't say where its lean... Low, Midrange or High RPM. Thougth I can't remember exactly where, this site has lots of info on both Factory and DynoJet jetting kits.
You might want to check the pilot (low speed) jets. The Factory kit replaces the stock 45s with 50s. Many on this list feel that 50s run too rich and have replaced them with 48s with good results.
Ron
You might want to check the pilot (low speed) jets. The Factory kit replaces the stock 45s with 50s. Many on this list feel that 50s run too rich and have replaced them with 48s with good results.
Ron
01-19-2006, 07:06 PM
#4
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RonVTR, everyone I've talked to leaned toward the 185/190 main jets so when I saw 175/178 main jets I wanted to double check what people were running. The pilot jets were 50s. This may explain his poor idle characterists when cold.
01-19-2006, 07:58 PM
#5
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Re: What jets to run?
Mine doesn't run well when cold either.
Let it warm up to about 150 before riding
Do a carb tune on it
TPS set at 500 ohms (+/- 10)
https://www.superhawkforum.com/viewtopic.php?t=153
Idle pilot jets #48 (see my post where to get them for $6.99 ea)
https://www.superhawkforum.com/viewt...849&highlight=
Jets of your choice. Mine is a Dynajet kit whose numbers are a little different from factory but I used 180 Front /185 Rear
idle mixture screws each turned out 2 and 1/2 turns from the bottom point (don't screw them down too hard or you could damage the seat...jst til they touch bottom then turn out 2 1/2 turns
count the needle notches from the flat end of the needle (opposite the pointed end)
while you have the slides apart clean them & lube lightly.) I used a silicone/teflon spray with NO oil to attract dirt. Don't forget the inside of the slide where it rubs the tube of the slide cap.)
https://www.superhawkforum.com/viewtopic.php?t=99
Check all your vacuum hoses & carb boots to be sure they are not cracked or leaking air.
Install & warm up bike to full operating temperature.
Set idle to 1300-1400 RPM. the recommended 1200 RPM is a little low
balance the carbs
Take it for a test ride!
Did you down load the free workshop manual off this site?
https://www.superhawkforum.com/viewt...661&highlight=
That's all I can think of right now.
What did I miss guys?
Pitch in & help him out....I'm sure I forgot something
Let it warm up to about 150 before riding
Do a carb tune on it
TPS set at 500 ohms (+/- 10)
https://www.superhawkforum.com/viewtopic.php?t=153
Idle pilot jets #48 (see my post where to get them for $6.99 ea)
https://www.superhawkforum.com/viewt...849&highlight=
Jets of your choice. Mine is a Dynajet kit whose numbers are a little different from factory but I used 180 Front /185 Rear
idle mixture screws each turned out 2 and 1/2 turns from the bottom point (don't screw them down too hard or you could damage the seat...jst til they touch bottom then turn out 2 1/2 turns
count the needle notches from the flat end of the needle (opposite the pointed end)
while you have the slides apart clean them & lube lightly.) I used a silicone/teflon spray with NO oil to attract dirt. Don't forget the inside of the slide where it rubs the tube of the slide cap.)
https://www.superhawkforum.com/viewtopic.php?t=99
Check all your vacuum hoses & carb boots to be sure they are not cracked or leaking air.
Install & warm up bike to full operating temperature.
Set idle to 1300-1400 RPM. the recommended 1200 RPM is a little low
balance the carbs
Take it for a test ride!
Did you down load the free workshop manual off this site?
https://www.superhawkforum.com/viewt...661&highlight=
That's all I can think of right now.
What did I miss guys?
Pitch in & help him out....I'm sure I forgot something
01-19-2006, 08:04 PM
#6
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Re: What jets to run?
Honda's jet prices are going to be expensive
call factory pro & order there instead.
Or try the M/C shop where I got my #48 idle mixture pilot jets
(last post in this thread)
https://www.superhawkforum.com/viewt...849&highlight=
By the way is the PAIR system still installed or has it been removed or disabled ???
https://www.superhawkforum.com/viewtopic.php?t=190
call factory pro & order there instead.
Or try the M/C shop where I got my #48 idle mixture pilot jets
(last post in this thread)
https://www.superhawkforum.com/viewt...849&highlight=
By the way is the PAIR system still installed or has it been removed or disabled ???
https://www.superhawkforum.com/viewtopic.php?t=190
01-19-2006, 11:23 PM
#7
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When counting the needle notches is number one at the bottom or top?
Ya know.. if the prices of the jets get to be over $30 all total, you might as well just get a jet kit.. its only like $40 shipped from Ebay.
01-20-2006, 12:36 PM
#8
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He only needs the main jets though. I think honda wants like $7 each. The PAIR valve has been removed and aftermarket block off plates have been installed.
I've heard 190/185 and 185/180. What should we run?
I've heard 190/185 and 185/180. What should we run?
01-20-2006, 07:23 PM
#10
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Re: What jets to run?
just in case....remember the richer (bigger number) goes in the rear cylinder because it tuns a little hotter than the front (I know....duh! )
$7 each from honda is OK....get them !
$7 each from honda is OK....get them !
01-20-2006, 07:39 PM
#11
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I appricate all the info. I've been wrenchin for a long time and have rebuild my share of carbs but its always nice to get a base line tuning spec before you start because carb tuning sucks! I remember my racing jetski had to be run richer on the rear cylinder because crank twist would advance the rear cylinder timing. Kind of like the cooling issue with the rear cylinder on the VTR. These are tips that are good to learn early or your bound to learn them the hard way.
Thanks all!
Thanks all!
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