carb help - Star Motorcycle Forums: Star Raider, V-Max, V-Star, Road-Star Forum
LinkBack Thread Tools Display Modes
post #1 of 3 (permalink) Old 01-13-2015, 11:36 AM Thread Starter
Junior Member
Join Date: Dec 2014
Posts: 14
carb help

Recently I noticed gas in my oil on my 08 vstar 1100. I have the theory that this was cause by a stuck float in the carb causing the piston to flood caucausing gas to leak into the crankcase. Took the carbs apart to clean and now the bike is bucking pretty hard at about 20-40 mph and backfiring with a steady throttle setting. Question is could the carb settings cause this and if so what are the stock settings? Which jet would cause these issues at this throttle position? Needle or pilot? No one has drilled the pms screw so it is still set and it doesn't happen with heavy acceleration. Mostly slow acceleration and when maintaining those speeds. Idles fine Could it possibly be something else other than carb related?Any help would be appreciated as I've already had the carbs off twice and it isn't a quick job to get in there to adjust stuff.
Hatchet is offline  
Sponsored Links
post #2 of 3 (permalink) Old 01-13-2015, 05:37 PM Thread Starter
Junior Member
Join Date: Dec 2014
Posts: 14
I don't know why this worked but i messed with the throttle free play and all of the issues settled down. I don't see how that makes any sense so if someone has an idea it would be appreciated. Thanks for the time.

Hatchet is offline  
post #3 of 3 (permalink) Old 01-13-2015, 07:49 PM
Premium Member
RestoRider00's Avatar
Join Date: Dec 2014
Location: Apopka Florida, a twist in the road just northwest of Orlando Florida My home for over 30 years
Posts: 1,052
TPS. The throttle position sensor. TPS has an adjustment procedure.
Earlier models like the 650 have the sensor. Mine does this just a little bit so I know what your referring to. At some slower engine rpm and mph it will try to buck a little. like a lean or possibly rich mixture. My bike has been jetted.
It had stock jetting in it with cobra pipes. It did not buck at all.
but it ran so hot it would blister your leg on the rear pipe in a second.
Way overly hot. I did the RAK mod to the stock bagel, K&N filter,
117.5 main jets, Stock pilot jets and bumped the PMS screws out to 3.5 turns. It runs fine. but still does just a little bit of what your talking about. At around 20 mph. So the jetting could still be tweaked
a bit more to fine tune but does not bother me. when I get on it it flys like the wind. Highway speeds it's awesome.


2000 Vstar 650 Classic , Firethorn orange Metal flake Urethane, OEM tall Windshield, 47 Harley Tail light mod, progressive springs, hard bags painted to match w/chr. bullet accents Custom Modified rear rack/backrest, Cobra Modified exhaust w/ chrome Pencil tips, Hyper charger kit,
PRV 15, Riser mounted speakers, Chrome levers,Fringe grips, studded Leather bib with pocket, Billet Oil filter relocation kit , 3.5 PMS w/ stock pilots, mains- 122.5, Custom billet t signals
RestoRider00 is offline  
Sponsored Links

Quick Reply

Register Now

In order to be able to post messages on the Star Motorcycle Forums: Star Raider, V-Max, V-Star, Road-Star Forum forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Please enter a password for your user account. Note that passwords are case-sensitive.


Confirm Password:
Email Address
Please enter a valid email address for yourself.

Email Address:


Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page
Display Modes
Linear Mode Linear Mode

Posting Rules  
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On

For the best viewing experience please update your browser to Google Chrome