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Discussion Starter #1
Recently got a V-Star with 5000 miles on it and on my first day it ran fine UNTIL it warmed up and then...

--Major loss of power
--seems to run fine cold
--difficult to even take off without it stalling.
--Idles fine
--exhaust pipe for the forward cylinder turned to a golden/brass color.
--seems to backfire some


I can limp home on it but not really rideable as max speed is maybe 45 or so.

Possible causes/fixes??

Any help will be greatly appreciated :)
 

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The first place I would start is making sure you are turning the choke off after warm up. Then check the air filter and intake to ensure that is clean and clear. Then change the fuel filter and make sure there is fresh fuel in the tank with the recommended amount of Sea Foam or similar fuel treatment.

Only after that would I begin looking at carbs, carb etc.
 

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Discussion Starter #3
I did change the Air filter (and plugs too) will change the fuel filter tonight. I haven't added seafoam but can. I am unsure what gas or treatment the previous guy used/added. I have and will be using startron but haven't added any yet.

  1. Drain tank
  2. Change Fuel Filter
  3. Sea foam
And go from there.

I assume theres 2 carbs on the VStar 650 ...1 for Each Cylinder?? I am thinking maybe a main jet on one is clogged.
 

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Discussion Starter #5
The bike is a 2008 and has sat for the winter. The previous owner swears it was winterized and so on and so forth but really who the heck knows. I think it's safer to assume it wasn't winterized.
 

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A 2008 with only 5000 miles is a very low mileage motorcycle at 7 years. It may have set for long periods of time and it could need more TLC to get her purring again. Do the stuff recommended and see how it goes. Augie
 

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Sounds like you are on the right track. One other easy thing to double check before tearing into carbs is to make sure plugs are getting spark. Check your plug wires to be sure they are good and not cracked etc.

If you have clean air, clean fresh fuel, are getting spark, and you still have the problem it will be time to look at carbs. If you tear down the carbs, they will need to be synchronized once they are reinstalled. You can search the web for accurate homemade devices for synchronizing them. We have an independent shop here that will rebuild carbs, reinstall and sych for $65 each. At that price, at least for me, the savings doing myself isn't worth the trouble. Other's mileage may vary.

I would give the Sea Foam or the treatment of your choice a day or two to work. Run the engine enough to get the treated fuel into the carbs and let it sit for a day or two. Maybe that will dissolve anything caught in a jet.


Good luck!
 

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Discussion Starter #8 (Edited)
Sounds like you are on the right track. One other easy thing to double check before tearing into carbs is to make sure plugs are getting spark. Check your plug wires to be sure they are good and not cracked etc.

If you have clean air, clean fresh fuel, are getting spark, and you still have the problem it will be time to look at carbs. If you tear down the carbs, they will need to be synchronized once they are reinstalled. You can search the web for accurate homemade devices for synchronizing them. We have an independent shop here that will rebuild carbs, reinstall and sych for $65 each. At that price, at least for me, the savings doing myself isn't worth the trouble. Other's mileage may vary.

I would give the Sea Foam or the treatment of your choice a day or two to work. Run the engine enough to get the treated fuel into the carbs and let it sit for a day or two. Maybe that will dissolve anything caught in a jet.


Good luck!
I looked at the plug wires when I changed the plugs and they visually looked good.

Fingers crossed. Thanks for the help. :)
 

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The exhaust pipe coloring is "usually" from it running lean and increasing temp. That cylinder is getting too much air and too little fuel.
 

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Discussion Starter #10
The exhaust pipe coloring is "usually" from it running lean and increasing temp. That cylinder is getting too much air and too little fuel.
Based on all I have heard, what SW1911ct said and speaking with a friend of mine who has some experience with Mikuni carbs.... It's sounding like a Jet is clogged probably a main jet.

He recommended as you all did, draining the tank, new fuel filter, new non-ethonal gas (he hates that stuff) and running some seafoam through it. Might get lucky and that will do it.

I got the Seafoam last night but didn't get a chance to get the non-ethanol gas or drain the tank... that'll be tonight. Thanks again for all your help and insight... will let you know how it goes.....
 

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The fact that the bike runs well cold would suggest the carb / jets / spark are OK. It almost sounds like a choke issue. Perhaps a stretched or mis-adjusted choke cable.
 

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The fact that the bike runs well cold would suggest the carb / jets / spark are OK. It almost sounds like a choke issue. Perhaps a stretched or mis-adjusted choke cable.
Except the discoloration of the front cylinder exhaust would mean overheating. Choke hanging would usually mean a rich condition wouldn't it? Rich would be a cooling situation versus lean would cause heating.

I'm still inclined to think carbs need cleaning eventually. But I'm always an advocate for ensure the simple is correct before jumping into more complicated. So checking the choke wouldn't hurt.
 

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Discussion Starter #13 (Edited)
So I .......

-Drained the tank
-removed the tank
-changed the fuel filter
-re-installed tank
-added about 2-3 oz of seafoam
-put in about 1.5 gallons of non-ethanol gas
-let it run for 10-20 mins

Still runs the same but as i was up "under the hood" I noticed there was some orange/brown molasses looking stuff seeping out of the questionable foward cylinder carb near the bowl i guess....not alot but it is there and you wouldn't notice but with the shop light on it and the tank off you do....

Also noticed as it was running out of the exhaust the front cylinder was "coughing" the back one was running fine or at least better anyway.

Going to let the seafoam work for a day or two then if it doesn't work ....i guess the carb comes off.
 

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The carbs on these bikes are fairly simple to clean. Check the CC&D
site for ZIV's jet kits. He also sells an allen head screw set for the carb bowls in stainless. Less Than $15.

Worth the price of gold. The stock bowl screws strip out VERY easily.
Lots of cursing after. Spray around both carb bowls 24 hours prior to trying to remove the screws. Use PB blaster for this .
Make sure to use a GOOD Screw driver. Plenty of grip and not worn.
And yes they are righty tighty lefty loosey.

Have new bowl gaskets on hand (bikebandit.com) New jets can also be ordered. Cleaning ANY of the jets with a wire will render them useless.

After the bowls are removed both pilot/jet holder and the main jet can be removed and cleaned with carb cleaner. The inner portion can be sprayed with carb cleaner A very light bristle brush or small paint brush can help dislodge junk. Be very careful around the float
slide out the pin and remove the float and needle seat assembly.
Hard or damaged needle ? (Bikebandit.com)

Just remember after your done with this and carbs installed anything
up stream of the fuel filter needs to be clean or well you get the picture.
EVEN THE FUEL PUMP.... must be cleaned or flushed out.
 

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Another little hint about the screws on the carburetor (and the rest of the bike, too). They may look like they are Philips screws, but THEY ARE NOT. They are JIS screws, and Philips screwdrivers WILL mess them up. You will play hell finding JIS screwdrivers, though the screwdrivers that came in your tool kit are probably JIS. JIS screwdrivers allow the screws to be torqued much tighter than Philips, which means Philips drivers will round off the screws when you try to unscrew them. Some have reported success by grinding off the rounded tip of the Philips drivers to allow them to seat a bit deeper. Impact screwdrivers are sometimes recommended, as well. Once you get the screws out, take them to your friendly local Ace Hardware and buy the same size screws, but with Allen heads. That will save you a LOT of grief, next time.
 

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Discussion Starter #16
Thanks everyone.... we took it apart yesterday and cleaned the carbs. They didn't look dirty but it made a world of difference.... like a new bike. Screws on the carb we used an impact driver and they came right off but as we were in there we noticed someone else had been as well.... maybe why he sold it so inexpensively. Still running the sea foam through and praying no more gunk get dislodged. ..though it looked pretty clean I am fairly sure we got it.
 

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Do not over look the inside of the gas tank. It can be the single most
contributor to carb and running issues that are fuel related.

Think of it as the mothers breast and your carb the suckling child.

Scale rust and crud in the tank makes for a nightmare in the ENTIRE
fuel system.
 

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Discussion Starter #19
Well just got done
--changed oil (used rotella 5w40 full sythetic t6)
--changed final drive gear oil (used 75w90 Mobil 1 gear oil)
--general cleaning with clean soapy water, then a wipe it down with a micro fiber cloth

My maintenance (i think) is done.....jusy need some warm weather and free time ;)
 

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Pull the tank, Drain as much fuel as you can into container.
Make sure to turn petcock to reserve position.

With all fuel drained now you can shine a flash light into the tank opening from above. A small pen light or LED pen light works great.
You will not see much ,but a dirty or sludged tank will show up all over the inside. So if you see a little, most likely the entire tank looks like this inside. Again a small pen light w/ 1 AA battery works great here. AND make sure not to drop it in the tank. Tape it to a stiff wire if you have to.

You can clean the tank with Acetone. You can seal the tank opening with a small ball, Dog ball or kids ball , wrapped in tin foil and then insert it in to a zip lock sandwich bag. This can then be jambed in the opening so that 2/3 of the ball sticks
out the opening. This will allow you to slosh the acetone around a good bit and not get any on the paint.
Just do not turn it upside down. Open petcock and drain make sure to unscrew the bottom bowl. After liquid drains
you can leave the tank open and it will air dry. after a few hours the tank should be fully dry.
You can use an air hose and compressor to blow out the tank. Partical's flying out can be a hazard so protect the eye's.
Put all back together and fill with your favorite beverage. I mean gas...
 
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