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2011 Yamaha VStar 650
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I had a shadow do the same I took it on a long ride and finally it cleared out. My 04 1100 vstar was the same way took 3 tanks of 93 octane to clear it out now it’s way faster tons of power
The 650 motor is designed to run on 87 octane. Running on higher octane is a waste of $ as the motor does not have high enough compression to burn it efficiently. This will actually cause a lean condition and can result in blueing of the exhaust manifold, and in extreme cases, burning of valves/pistons.
 

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2001 Yamaha XVS650 Dragstar Classic and 1999 Honda NT650V Deauville
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A bad spark plug can also give signs that looks like fuelling issues, so personally I would fit new plugs and see if they make any difference. Doing many things at once always leave one with the doubt of what it was that did the trick ;)
 

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Discussion Starter #23
A bad spark plug can also give signs that looks like fuelling issues, so personally I would fit new plugs and see if they make any difference. Doing many things at once always leave one with the doubt of what it was that did the trick ;)
Already did the plugs. No difference.

Also something I didn't mention actually was when I'm giving it throttle it almost acts like it's running on one cylinder. When idling and starting up it does just fine.
 

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Ouch. Don't need to remove the carbs to clean the jets. You tube video, can do it yourself. If i can, anybody can! Take pictures. Use a JIS screwdriver, should be one in your tool kit.. Need some cab cleaner, and take your time. Or spend the 300-600 bucks. While you're at it replace the fuel filter too. Les is right, it really sounds like your main jets are clogged. If not, then cc&d jet chart for sizes to start... Ask and we can talk you through it, or check out the diy videos...
Mine are fine it’s the other guy I got lucky and was able to drive mine clean
 

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2006 Stratoliner, 2014 Triumph Rocket III Touring, '81 XS650SH Project
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So I smelled the oil and it does smell like it has some gas in it so I think at this point I'm pretty sure the carbs need to come off and rebuilt but I'll have them rejetted as well to help the backfire. I'll be talking to some shops tomorrow and keep you guys updated once I get to the point of taking the carbs off to take to the shop.

I'll also look into the fuel filter but I don't think it's going to be that because if it was clogged then it wouldn't be running rich but more lean I feel like.

Thank you so far to everyone who has posted their advice and ideas.
Brother, I encourage you to do the carb work yourself. I am no mechanic at all, but I once had over a hundred Revelle models or cars, bikes, aircraft ships... I had never rebuilt a carburator but watched the one I needed to do on YouTube and successfully rebuilt one for a lawn tractor. My Pretty Pillion wants to rebuild the two on my XS650 project because she too loves working with small parts. She builds fantastic Lego, metal art and wood models. If you do the work yourself, not only is it less expensive, but the satisfaction you get when done cannot be measured. And, you add a new skill to your personal toolbox.
 

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Discussion Starter #27
Brother, I encourage you to do the carb work yourself. I am no mechanic at all, but I once had over a hundred Revelle models or cars, bikes, aircraft ships... I had never rebuilt a carburator but watched the one I needed to do on YouTube and successfully rebuilt one for a lawn tractor. My Pretty Pillion wants to rebuild the two on my XS650 project because she too loves working with small parts. She builds fantastic Lego, metal art and wood models. If you do the work yourself, not only is it less expensive, but the satisfaction you get when done cannot be measured. And, you add a new skill to your personal toolbox.

Your right I can do it myself and i know i can it's just the fact i dont know how to determine what jet sizes I'll need for the carbs to rejet them and also a shop has special cleaning machines that do a lot better than you can do by hand. Plus like I've stated before I dont like working on carbs, done it before and it was a pain to retune it and time consuming with all the disassembly and cleaning of them.
 

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Your right I can do it myself and i know i can it's just the fact i dont know how to determine what jet sizes I'll need for the carbs to rejet them and also a shop has special cleaning machines that do a lot better than you can do by hand. Plus like I've stated before I dont like working on carbs, done it before and it was a pain to retune it and time consuming with all the disassembly and cleaning of them.
I totally agree on the not liking the carb work. I will do it if i have to but only on my own stuff.
 

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Talking about rejetting.. Do you have a stock airbox? Usually don't need to rejet with just an aftermarket exhaust.. unless the p.o. already messed things up.. Here's the chart that everyone recommends 650 CC & Dl Keep us updated. Can't stand the suspense
 
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Discussion Starter #32
Talking about rejetting.. Do you have a stock airbox? Usually don't need to rejet with just an aftermarket exhaust.. unless the p.o. already messed things up.. Here's the chart that everyone recommends 650 CC & Dl Keep us updated. Can't stand the suspense

It is a stock airbox but wouldn't the rejetting fix the backfiring? If not then how do I fix the backfiring?

Weird for me to want to fix backfire because I come from a car community where backfiring isn't that big of an issue but as seeing it's on a carburetored motorcycle I have concerns.
 

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2008 vstar 1100 classic canadian edition
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is US gas different than canadian gas? i had gas 2 yrs in a jerrycan (winter and summer temps) no stabilizer in it and was fluid as the day is long. put in a dirt bike that had been sitting for 5 yrs 3 kicks and it started and ran fine.
 

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It is a stock airbox but wouldn't the rejetting fix the backfiring? If not then how do I fix the backfiring?

Weird for me to want to fix backfire because I come from a car community where backfiring isn't that big of an issue but as seeing it's on a carburetored motorcycle I have concerns.
Adjust PSM screws (Air/fuel mixture) out about 1/4 turn to lessen the decel popping.
Located on bottom of carb.

97159
 

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is US gas different than canadian gas? i had gas 2 yrs in a jerrycan (winter and summer temps) no stabilizer in it and was fluid as the day is long. put in a dirt bike that had been sitting for 5 yrs 3 kicks and it started and ran fine.
It depends... A lot of US gas has up to 10% ethanol in it. It's the ethanol that causes the issues...
 

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So I just picked up a 1998 v star 650 with pretty low miles and on the way home on the freeway I can't get it to go above 60 mph. WOT in 4th and 5th and they both won't go above 60. It also feels like its lacking power in general when accelerating. Give it a lot of gas and it feels like it cuts the power. On top of this it has aftermarket cobra pipes and it backfires a lot.

Replaced the air filter today- no difference in anything.
Pulled spark plug and its black on the end but not too bad. Gonna have those replaced tomorrow and test plug wires as well.

Don't want to take the carbs off and get them jetted and tuned and that not solve my power loss.

Any advice is much appreciated. I'm mechanically inclined and understanding of engines so tell me what you guys think this could be. :)
I have an 03 650 and i had put a hypercharger on it I was told by my local Yamaha dealer to rejet and adjust the mid also which made my bike do the same 1 through 3 great 4 and 5 sluggish beyond belief , then I did some digging and found that I only had to rejet the other 2 not all 3 so I put the mid back to where it was re tuned the carbs to get rid of most the back fire on decel and it runs great. I dont really care for sea foam I dont mind rebuilding carbs it relaxes me.
 

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So I just picked up a 1998 v star 650 with pretty low miles and on the way home on the freeway I can't get it to go above 60 mph. WOT in 4th and 5th and they both won't go above 60. It also feels like its lacking power in general when accelerating. Give it a lot of gas and it feels like it cuts the power. On top of this it has aftermarket cobra pipes and it backfires a lot.

Replaced the air filter today- no difference in anything.
Pulled spark plug and its black on the end but not too bad. Gonna have those replaced tomorrow and test plug wires as well.

Don't want to take the carbs off and get them jetted and tuned and that not solve my power loss.

Any advice is much appreciated. I'm mechanically inclined and understanding of engines so tell me what you guys think this could be. :)
So I had the exact same problem on mine and it was the throttle position sensor or something i also had the carbs cleaned before but after 10-30 miles it just bogged down after 40mph
 

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My Pretty Pillion loves working with small parts.
I couldn't resist, sorry Boog!

And if the carbs needed cleaning, you need to empty and RINSE the tank and replace the fuel filter. Make sure the fuel hoses are drained. It may not seem like it, but it only takes one small blob of jello'd fuel to cause lots of problems. Some of the older posts here a poster will say " I had the carbs cleaned, but soon after starting it the engine had the same problem" . Only to find out they started it with the same fuel in it that gummed up the carbs to begin with!!
 
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