Yamaha Starbike Forum banner

1 - 15 of 15 Posts

·
Registered
Joined
·
7 Posts
Discussion Starter #1
Hi All! This looks to be a GREAT forum.

I have a 2008 Vstar 1300 cruiser w/5k miles. Has always run great, no problems. 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 kinda dangerous actually.

My first thought is it's a fuel system issue. Misfiring injector(s), dirty fuel filter, etc. Electrical ... misfiring coil? Any thoughts or advice is GREATLY welcomed and appreciated.

Thanks!
 

·
Registered
Joined
·
5,436 Posts
was the bike parked for a while.. like months.. without being used?

could there be water in the fuel?

A treatment with a fuel additive would be a good place to start: $8 for a bottle of Seafoam at Walmart.

you are correct, its very dangerous - throttle controls the turn rate in a corner - if it stumbles in a curve it will throw you inside

just to be clear, the bike is a Vstar 1300 2 cylinder, not a Royal Star 1300 V4, right?
 

·
Registered
Joined
·
2,237 Posts
Welcome from Atlantic Canada. This is indeed a great forum and as you can see the members here are always happy to help. Now that you've introduced yourself here, may I suggest reposting your problem in the proper forum where it will get more views?

And we're kinda big on pics here so post one of your ride when you get a chance.
 

·
Registered
Joined
·
7 Posts
Discussion Starter #4
was the bike parked for a while.. like months.. without being used?

could there be water in the fuel?

A treatment with a fuel additive would be a good place to start: $8 for a bottle of Seafoam at Walmart.

you are correct, its very dangerous - throttle controls the turn rate in a corner - if it stumbles in a curve it will throw you inside

just to be clear, the bike is a Vstar 1300 2 cylinder, not a Royal Star 1300 V4, right?
It was sitting for awhile but I had the problem before I parked it. I tried Seafoam before I parked, no change. Yes it is a Vstar 1300.
 

·
Registered
Joined
·
7 Posts
Discussion Starter #7
Premium gas ...hmmm. Why would just higher octane gas cause a problem? Maybe has a higher % of water due to longer time in station storage tanks? I think I did use premium at last fill up.
 

·
Super Moderator
Joined
·
4,625 Posts

·
Super Moderator
Joined
·
6,088 Posts
Welcome to the forum from East Tennessee. Nice clean looking 1300!
I ride the 950, the 1300 little brother, I’ve tried all grades of fuel and I found no difference in using premium. Now using non-ethanol makes a difference, 87 octane non-ethanol works fine for me. Just a suggestion.


Sent from my iPhone using Tapatalk
 

·
Registered
Joined
·
1,298 Posts
Welcome to the forum from East Tennessee. Nice clean looking 1300!
I ride the 950, the 1300 little brother, I’ve tried all grades of fuel and I found no difference in using premium. Now using non-ethanol makes a difference, 87 octane non-ethanol works fine for me. Just a suggestion.


Sent from my iPhone using Tapatalk
I run 87 octane crapanol that is because crapanol is all i can get
 

·
Registered
Joined
·
19 Posts
Premium gas ...hmmm. Why would just higher octane gas cause a problem? Maybe has a higher % of water due to longer time in station storage tanks? I think I did use premium at last fill up.


Because the higher octanes burn at different rates and vapor pressures and the engine has to be designed around that timing. 92 in an engine designed around 87 will not completely burn in time and there will be flame still when the exhaust valve opens. Adjusting idle helps some, but 92 burns for a longer time and then You can get pre AND post ignition in the same stroke.

Overall less performance due to the burn rate difference.


Sent from my iPad using Tapatalk
 

·
Registered
Joined
·
961 Posts
Because the higher octanes burn at different rates and vapor pressures and the engine has to be designed around that timing. 92 in an engine designed around 87 will not completely burn in time and there will be flame still when the exhaust valve opens. Adjusting idle helps some, but 92 burns for a longer time and then You can get pre AND post ignition in the same stroke.

Overall less performance due to the burn rate difference.


Sent from my iPad using Tapatalk


I always filled up my Stryker which has the same engine as OP’s VStar with 93 and never had any issues.


Sent from my iPad using Tapatalk
 

·
Registered
Joined
·
5,436 Posts
I always filled up my Stryker which has the same engine as OP’s VStar with 93 and never had any issues.
thats interesting - in a stock bike designed to run 87 putting 93 in the tank will make it run lean - as in burn holes thru your pistons lean

what do your plugs look like when you change them?

have your re-tuned the bike to run richer?

the other consideration is hi octane gas has lower energy density than regular

you will get fewer miles per gallon running premium than regular, there is no way around that. If you do not have a hi compression engine that needs premium, you are paying more for the fuel and getting less miles per tank.
 

·
Registered
Joined
·
961 Posts
thats interesting - in a stock bike designed to run 87 putting 93 in the tank will make it run lean - as in burn holes thru your pistons lean

what do your plugs look like when you change them?

have your re-tuned the bike to run richer?

the other consideration is hi octane gas has lower energy density than regular

you will get fewer miles per gallon running premium than regular, there is no way around that. If you do not have a hi compression engine that needs premium, you are paying more for the fuel and getting less miles per tank.
Thanks KCW. Guys on Stryker forum said that running premium gas helped with performance, but like Les said I've tried all octane grades and didn't feel any difference, just thought that higher octane gas burns at higher temperature and helps to reduce internal buildup. Plugs actually looked a bit lean, but not terribly lean. They were light yellow to white color, but no ash color. I gotta find a picture of the plugs that I used to have. I re-tuned the bike when changed the exhaust and intake using EJK fuel controller and was checking plugs to make sure all was good and it seemed to be.

Sent from my SAMSUNG-SM-G925A using Tapatalk
 
1 - 15 of 15 Posts
Top