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07 v star 650 wont rev past 1/4 throttle..

25377 Views 33 Replies 14 Participants Last post by james.alan.howard, 2 d ago

fueler191

Discussion Starter · Jul 2, 2012

Ok, so i have a 2007 V star 650 custom. I have owned the bike since new and have never had issues with it. I parked it two years ago with starts over the first year and then none over the last. This season i pulled it out to sell and i drained the tank, replaced the fuel filter and battery, added new gas and took it around the block. Ran great. Sold the bike basically, brother in law took it to deliver it and get the cash, and as hes riding it for about 10 minutes, all of a sudden it starts bogging and spitting after 1/4 throttle. Brought it home, first thing i thought, carbs. Took them apart, cleaned em out good, everything looked good in them too, seemed very minimally gummed up. Put them back on, did the exact same thing. Next up blew out all the lines, made sure the petcock flowed, and the tank vent was all good. still nothing. Replaced the plugs, nothing. Took the carbs off again, cleaned again, nothing. Took the carbs to a shop to be cleaned better than i could, nothing. changed the oil, changed regulator/rectifier, nothing. Coils seem to be fine. Checked for vaccum leaks, thought i found the issue as the engine reved a bit higher when sprayed at the carb boots, replaced those....not a thing changed. I am seriously at a loss for what it could be...any ideas? Ive been reading the forums on here as well as else were for people having similar issues, and have tried everything... Help!!!

21 - 34 of 34 Posts

fueler191

Discussion Starter · #21 · Sep 4, 2012

i read your thread and went straight at the PMS screws...the needles at the end of them had a little carbon on them but nothing else...flow was good in the hole...pulled the spring, and the oring/washer just to rub it out with a little cleaner...

now that i have done that how far out do they need to be turned? and i replaced my rectifier/regulator a long time ago...and the CDI recently..im back to the carbs...there has to be something clogged somewhere

mrwalters

· #22 · Sep 4, 2012

Mine didn't have anything noticeable in the pms screw hole either.
The biggest affect was reinstalling the air box, it needed a restriction on the intake.
Try the squirt bottle w gas and see if that helps

nt7332

· #23 · Dec 6, 2012

What was the fix for this I'm having the same issue..

fueler191

Discussion Starter · #24 · Aug 22, 2013

It has not been fixed yet. Ive gone through 2 electrical engineers, 1 mechanical engineer, 1 Yamaha mechanic, 1 Harley mechanic and another multi specialty mechanic...........at this point the bike is a novelty...like the damn sword in the stone....

eGo

· #25 · May 4, 2015

Sorry to drag up the moldy oldie.. But is it still a novelty? Or did you manage to get it fixed?

fueler191

Discussion Starter · #26 · Aug 14, 2015

Still not running.

At this point it is a novelty. Every time we meet a guy that claims to be able to fix anything on any bike or any engine....we give him this. NO ONE can figure it out, at this point ive blindly spent more than the bike is worth trying to fix it.

5 shops have now had it as well. 4 of which refused to listen to me and swore that the carbs would fix it....they didn't....

Summer

· #27 · Aug 14, 2015

If no one has done so yet I would try a compression test and a leakdown test. At this point you have nothing to lose.

LynxSS

· #28 · Aug 15, 2015

Bummer, If you were anywhere in New Mexico I'd have you up and running in a day or two. I've fixed at least a half dozen bikes that their owners had given up on that would idle and nothing else and a few more that wouldn't even do that. My personal one is doing this now also after sitting for 2 years.

For me it has almost always been the carbs, the passage ways get gummed up past the jets in the bodies. Another time it was a rotted vacuum port cap at the elbow, another time it was a rusted AIS line, and yet another time that took me a while to figure out the TPS sensor was bad. But the majority of the times its been carbs and most of the time they'd already had it cleaned by a "pro" with no luck, I don't know what the heck the pros do but a cheap can of carb cleaner and a $4 acetylene torch brush kit in a driveway fixed what they couldn't.

Usually it is something simple to fix it is just finding what it is.

Zman3

· #29 · Mar 27, 2021

fueler191 said:
Ok, so i have a 2007 V star 650 custom. I have owned the bike since new and have never had issues with it. I parked it two years ago with starts over the first year and then none over the last. This season i pulled it out to sell and i drained the tank, replaced the fuel filter and battery, added new gas and took it around the block. Ran great. Sold the bike basically, brother in law took it to deliver it and get the cash, and as hes riding it for about 10 minutes, all of a sudden it starts bogging and spitting after 1/4 throttle. Brought it home, first thing i thought, carbs. Took them apart, cleaned em out good, everything looked good in them too, seemed very minimally gummed up. Put them back on, did the exact same thing. Next up blew out all the lines, made sure the petcock flowed, and the tank vent was all good. still nothing. Replaced the plugs, nothing. Took the carbs off again, cleaned again, nothing. Took the carbs to a shop to be cleaned better than i could, nothing. changed the oil, changed regulator/rectifier, nothing. Coils seem to be fine. Checked for vaccum leaks, thought i found the issue as the engine reved a bit higher when sprayed at the carb boots, replaced those....not a thing changed. I am seriously at a loss for what it could be...any ideas? Ive been reading the forums on here as well as else were for people having similar issues, and have tried everything... Help!!!

Zman3

· #30 · Mar 27, 2021

Ok, I was working on a bike with the exact same problem - worked fine before sitting for two years, after starting - the engine wouldn't run properly. Tried everything that you tried - cleaned the carburetors in an ultrasonic tank twice, replaced the ecu, coils, throttle position sensor, adjusted the valves, installed new spark plugs, etc., finally replaced the carburetors and the engine ran great. took the carburetors apart again knowing that there had to be a problem in the carburetors - found the float needle seat o-rings were loose - installed new o-rings and re-installed the original carburetors - the engine is running normally now. It was hard to diagnose because it wasn't flooding, the spark plugs came out looking like new and the engine felt like it was starving for gas but running with the choke on didn't make a noticeable difference, and playing around with the air filter opening didn't help, I also tried installing larger main jets and raising the slide needles. This was definitely one for the books. Hope this helps

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compjan

· #31 · Mar 29, 2021

Thanks for the update!

Zman3

· #32 · Apr 3, 2021

fueler191 said:
Ok, so i have a 2007 V star 650 custom. I have owned the bike since new and have never had issues with it. I parked it two years ago with starts over the first year and then none over the last. This season i pulled it out to sell and i drained the tank, replaced the fuel filter and battery, added new gas and took it around the block. Ran great. Sold the bike basically, brother in law took it to deliver it and get the cash, and as hes riding it for about 10 minutes, all of a sudden it starts bogging and spitting after 1/4 throttle. Brought it home, first thing i thought, carbs. Took them apart, cleaned em out good, everything looked good in them too, seemed very minimally gummed up. Put them back on, did the exact same thing. Next up blew out all the lines, made sure the petcock flowed, and the tank vent was all good. still nothing. Replaced the plugs, nothing. Took the carbs off again, cleaned again, nothing. Took the carbs to a shop to be cleaned better than i could, nothing. changed the oil, changed regulator/rectifier, nothing. Coils seem to be fine. Checked for vaccum leaks, thought i found the issue as the engine reved a bit higher when sprayed at the carb boots, replaced those....not a thing changed. I am seriously at a loss for what it could be...any ideas? Ive been reading the forums on here as well as else were for people having similar issues, and have tried everything... Help!!!

Zman3

· #33 · Apr 3, 2021

Ok, so after thinking about my last post about the running issue on the V-Star 650, I think I should follow up by saying that on the last carburetor cleaning, (when I discovered the float needle seat o-rings were loose), I had also removed the decel valves and cleaned the brass end in case they had been sticking. The inner decel valve can be removed without disassembling the carburetors although it does require a little effort and a small channel lock plier and a small needle nose plier. It would make more sense that they were sticking based on the running symptoms.

james.alan.howard

· #34 · 2 d ago

I just thought I would throw this in here to save someone the headache I just went through. I found a solution to a problem just like this and it took 14 hours of digging to find it. Same symptoms as this thread. The pin that held the emulsion tube from spinning slid out 1/16 of an inch and allowed it to turn when tightening it down. That’s all, seriously. The 10 degrees of turning caused it to cutoff fuel flow and not run on that cylinder. Tap the pin back in and tighten it down, done.

21 - 34 of 34 Posts