Vstar 1300 performance problem - Star Motorcycle Forums: Star Raider, V-Max, V-Star, Road-Star Forum
 16Likes
  • 1 Post By Gearheadzgarage
  • 3 Post By lesblank
  • 4 Post By KCW
  • 2 Post By Gearheadzgarage
  • 3 Post By KCW
  • 3 Post By Gearheadzgarage
 
LinkBack Thread Tools Display Modes
post #1 of 6 (permalink) Old 08-03-2019, 01:41 PM Thread Starter
Junior Member
 
Join Date: Oct 2018
Location: North Florida
Posts: 7
Vstar 1300 performance problem

I have a 2008 Vstar 1300 cruiser w/5k miles. Has always run great, no problems. Garaged & covered. Ride on weekends.

An issue cropped up recently. It idles fine with no apparent miss but under any load, it has terrible throttle response with no power and sounds like its not running on all cylinders until the engine wakes up and almost throws me off the bike. Once it "wakes up", it has normal strong power if I stay on the throttle but as soon as I get off the throttle, it returns to the muted throttle and power. If I get back on the throttle, the process repeats itself ... no power and sounds crappy then all of a sudden, switch flipped and I'm off to the races again. It's really dangerous actually.

My first thought is it's a fuel system issue. Misfiring injector(s), dirty fuel filter, etc. I added some Seafoam to the fuel no change. Electrical ... misfiring coil? Any thoughts or advice is GREATLY welcomed and appreciated.

Thanks!
Keith Post likes this.
Gearheadzgarage is offline  
Sponsored Links
Advertisement
 
post #2 of 6 (permalink) Old 08-03-2019, 03:35 PM
Moderator
 
lesblank's Avatar
 
Join Date: Jan 2014
Location: Houston, Texas
Posts: 3,998
Garage
I would change plugs. The spark plug has a built in resistance to help deliver a clean spark. When resistance gets high, due to age, fouled, etc, it will fire easily without a load, at idle. The coils deliver more energy the higher the RPM and plug might be "breaking down". It's a cheap place to start. Post back results.

2001 Vstar 1100 Classic (sold), Cobra Slash Cut full exhaust, Dropped 1 inch with lowering links, ORK, 4.5 inch handlebar risers, Ultimate passenger seat, Passenger pegs moved forward 4 inches, Handlebar clock, KN air filter, Viking saddlebags, Additional rear lighting
Loose nut "me" behind the bars
2006 Harley Electra Glide Ultra Classic

https://sites.google.com/site/vstar1100kb/home
lesblank is online now  
post #3 of 6 (permalink) Old 08-03-2019, 04:15 PM
KCW
Senior Member
 
Join Date: Sep 2016
Posts: 5,087
Garage
there was a comment in your new member thread about premium gas

these bikes are tuned to run on the fuel octane listed in your owners manual (you can down load them free from yamaha if you dont have one for your bike).

On carbed bikes the jets are sized for the fuel octane called out. On your fuel injected bike the fuel/air ratio is mapped the same way. Unlike a car with a full closed loop O2 sensor feedback long term adjustment, the fuel injection on these bikes does not self adjust when you change octane rating, or change the exhaust, or put a bigger air filter on for more air.

I know it sounds backward but regular octane fuel has more energy per ounce than hi octane. If you put premium in a bike that is set up for regular, it will run lean - with the highest grade premium it will run very lean, stumble, sputter.

It sounds like what your bike is doing is more severe than that, so it might be more than just the premium gas. Checking your plugs like Les suggested is a good start, esp if you dont know the last time they were changed.

Also take a look at your air filter - it should be white like paper, not grey, not tan... If your air filter is dirty it would throw the air/fuel mixture the other way, acting like the engine is choked and it will run rich - but most noticable when the throttle is wide open. Your bike seems to be doing the opposite - idling rough but ok with a lot of throttle twist. So the odds are worn plugs or premium fuel.

If you want to check the fuel, pull the line off the petcock and drain it out into a gas can, put that in your car, and fill the bike with regular octane.

Last edited by KCW; 08-03-2019 at 04:18 PM.
KCW is online now  
Sponsored Links
Advertisement
 
post #4 of 6 (permalink) Old 08-03-2019, 07:17 PM Thread Starter
Junior Member
 
Join Date: Oct 2018
Location: North Florida
Posts: 7
Thanks Les and KCW .. all good advice.

I drained the premium fuel from the tank. I really think it's a fuel system issue resulting in fuel starvation. It idles perfectly but going full throttle off idle or low rpm cruise and almost no acceleration occurs for like 5 seconds until the rpm suddenly shoots up, as it should when full throttle is applied. My Suzuki 4 stroke boat engine was having similar behavior and it was a bunch of crap in the high pressure fuel filter just before the injector rail.

As you all advised, I'm going to put some fresh regular fuel in the tank and change the plugs and air filter.

I'll report back. Mark

Last edited by Gearheadzgarage; 08-03-2019 at 09:19 PM.
Gearheadzgarage is offline  
post #5 of 6 (permalink) Old 08-03-2019, 09:59 PM
KCW
Senior Member
 
Join Date: Sep 2016
Posts: 5,087
Garage
if you think there is an issue with the fuel pump its not hard to check the pressure and flow

youll need a fuel pressure gauge - not sure at what point its easier (cheaper) to have a shop check it out than to buy the equipment you would need to debug the fuel injection system.

you should at least be able to pull the hose off the fuel pump and see if the flow is restricted
KCW is online now  
post #6 of 6 (permalink) Old 08-04-2019, 01:00 PM Thread Starter
Junior Member
 
Join Date: Oct 2018
Location: North Florida
Posts: 7
Quote:
Originally Posted by KCW View Post
if you think there is an issue with the fuel pump its not hard to check the pressure and flow

youll need a fuel pressure gauge - not sure at what point its easier (cheaper) to have a shop check it out than to buy the equipment you would need to debug the fuel injection system.

you should at least be able to pull the hose off the fuel pump and see if the flow is restricted
Good idea! I'll add new reg fuel, new plugs & new air filter. If no fix, I'll do the simple pump test. If flow/pressure doesn't check out, I'll also consider pulling fuel pump to check strainer and/or reserve fuel tank to check for gunk or debris.
Gearheadzgarage is offline  
Sponsored Links
Advertisement
 
Reply

Quick Reply
Message:
Options

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

Password:


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

Email Address:
OR

Log-in










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