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help i have tried everything to fix my bike .I have a 2003 v-star 1100 it started poping through the carb then it wont rev up but will idle fine.i have taken the whole motor apart.check the valves for leaks arounds the seets put new plugs in it,new gas, check the valve lash set it to factory .and check the timing compression is good .I don't know about the sensors maybe it could be a sensor.can some one let me know what they think or if they has a similar problem with there v-star.help it has to be something dumb.:fight1:
 

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I have the service manual. Let me take a look tonight or tomorrow based on your symptoms. Will get back to you.
 

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This sounds like a blocked pilot circuit or possibly incorrect float level. I would suspect the carbs to be the problem. As Bigs has the manuel see what he comes up with as there well may be a sensor somewhere that is playing havoc

Good luck
 

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Sorry I haven't replied sooner. Sick toddler in the house. Ok, first let's start with the obvious. Is the engine light staying "on" or "blinking"? It should come on when you first start the bike (self - diagnosing for any problems), but then go out if all seems ok. If it goes out like normal, we have a few sections in the manual for troubleshooting items. They are: Starting failure/hard starting, Poor idle speed performance, and Poor medium-and-high speed performance. I am guessing by your symptoms, it is the last one. If this is the case, it could be one (or all) of the following: Carburetor (faulty diaphragm, improperly adjusted fuel level, and/or clogged or loose main jet), Air filter (clogged air filter element), Fuel pump (faulty fuel pump). Let me know what you think.
 

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From what Bigs has posted and your earlier post of the symptoms I would suggest a very lean condition when throttle is applied. This is obviously a fuel supply issue. If a fuel pump is fitted I would start there...check the flow and make sure the pump is running consistantly......could even be a loose wire/bad ground connection. Next check the float height...Ask Bigs to find out what the setting should be. If nothing has been recently changed in the carbs and you didn't fit anything else then move onto blocked jets, pilot circuit would be my guess. EasyRider reckons Berrymans Gumout is good so try that or a similar product. Give these points a try and let us know how you go.

Good luck
 

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Measuring and adjusting the fuel level,
Correct reading: fuel level (above the line on the float chamber) = 4 x 5 mm (0.16 x 0.20 in)
Stand the motorcycle on a level surface
Place the motorcycle on a suitable stand to ensure that the bike is standing straight up
Install the fuel level gauge (part YM-01312-A, 90890-01312) to the fuel drain pipe
Loosen the fuel drain screw
Hold the fuel level gauge vertically next to the upper face of the float chamber
Measure the fuel level
Note: fuel level readings should be equal on both sides of the carb assembly
To adjust if out of tolerance:
Remove carb assembly
Check needle valve seat and needle valve
If either is worn, replace them as a set
If both are fine, adjust the float level by slightly bending the float tang
Install the carb assembly
Measure again
Repeat adjustment steps until fuel level is within spec
 

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Great advice!

Just a thank you for leaving this thread up... I had similar issues and was almost ready to buy new carbs.. turned out to be the only thing I didn't check... plugged idle jets!
 

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Help

Took carburetor apart, cleaned, new battery and now start. Got started before brought home. Had to clean carbs because sat for two years:fight2:What now?
 

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Took carburetor apart, cleaned, new battery and now start.
What ??? I think maybe you mean WON'T START.........anyhow, since you already started another thread about this, how about you just stick with that one, OK ??
 

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I have a 04 V-Star 650 classic and it will idle with both cylinders running but as soon as you give it throttle the rear cylinder stops running. I have checked the plugs, spark, and cleaned the carbs with no help. I have also checked for leaks and turned the air/fuel mixture screw and nothing helps. It is very weak when I ride it. It also backfires out the rear cylinder exhaust when you release the throttle and sometimes flames shoot out the exhaust, but just the rear cylinder. The bike had been sitting for 3 years when I bought it. Can anyone help me find the problem? Thanks Aaron
 

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recheck the rear carb...if the bike sat for three years there is certainly going to be some sort of blockage....as I said before the pilot circuit is probably the culprit. One other thing for you to check would be all the rubber parts of both carbs...after three years sitting they may well have perished pay particular attention to the diaphragms if they are CV carbs checking for pinholes....also check the boots from the air box and to the head
 

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Thanks

Thanks for the reply. I have cleaned and checked everything in both carbs and checked the boots, but I will recheck it all again. Would there be anything else that would cause this? Thanks again. Aaron
 

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Aaron there are many reasons for a lean condition mostly taken care of in the previous posts....this is usually what causes the carb to spit back. The only other thing I can think of would be a timing issue on the rear cylinder but for this to 'just occure' is highly unlikely so unless you fiddled with something that you haven't told us about it is most probably one of the mentioned causes. It is very important to check the pilot circuit very carefully as the jets, just after the venturi, are very tiny and easilly clogged...soaking in a carb cleaner overnight is sometimes all that will clear it and even then you may have to boil the metal parts in vinegar and water as a last resort.

Good luck
 

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Ok. Here is what I found. I pulled the carbs back off and cleaned the rear one again and found that the diaphram had a rip in it. So I replaced it and still the same. I changed the intake boots with new ones and still no change. The back cylinder will start running with the choke pulled out but when you push it back in the rear cylinder will quit running as soon as you give it gas. I haved pulled my hair out and could use some help. Thanks Aaron
 

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Ok check the spring in the rear carb is not 'cocked' over....the slide must rise and fall cleanly....if possible remove the air intake boot and feel this action with your fingers as you operate the throttle. Easiest thing to do is remove the cap and with the boot removed push the slide up to its highest position whilst lowering the top this will prevent the spring from fouling. On most CV carbs there is a small 'o' ring fitted to the top this is the seal for the pilot circuit and must be in place.

Check the float height of the offending carb if it is too low it will not get sufficient fuel and too high will flood that cylinder.

Check the emulsion tube...usually directly below the main jet....consists of a tube with tiny holes to inject more air deeper in to the incoming fuel at higher rpms.....will affect idle to some degree too. Make sure the cables are on the correct way round...ie the pull cable actually pulls the carb mechanism and the return one pulls it when closing the throttle. Revisit the pilot circuit I cannot stress enough how easy it is to clog this up and it sounds just like the problem you are having.

Make sure the float valves are not clogged or failing to seal as this will stuff the float level up...what colour are the plugs...soft sooty colour = rich and white blistered colour = lean. Check these as it will indicate a very lean condition on the offending carb if it exists which should help you diagnose the problem.

Make sure all specs are the same for both carbs and visually check they are identical and have all the same fittings. One final thing make sure the boots are not overtightened as this can cause as many problems as a loose one. One other thing what is the ilde like on the rear carb...try raising it to see if this helps.

CV carbs can be a pain but once set up correctly are very precise and responsive.


Good luck and don't set fire to it yet lol!
 

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Ok I cleaned the rear carb again and blowed it out real good and still no change. While it was running I pulled the rear plug wire off and it started to run with the plug wire half off of the plug. Put it back on and rear cyclinder stop running again. Pull it back half off and it would start running again. What would cause this?
 

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help i have tried everything to fix my bike .I have a 2003 v-star 1100 it started poping through the carb then it wont rev up but will idle fine.i have taken the whole motor apart.check the valves for leaks arounds the seets put new plugs in it,new gas, check the valve lash set it to factory .and check the timing compression is good .I don't know about the sensors maybe it could be a sensor.can some one let me know what they think or if they has a similar problem with there v-star.help it has to be something dumb.:fight1:
Change the plugs, the 1100s like to do funny things with the pluds
 

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Thanks but it is a 650 and I have changed the plugs about 3 or 4 times.
That reply was to someone else.
Are your new plugs properly gapped.......and are they the right ones ??

At this point, I think you need to start looking at an electrical/spark problem instead of fuel.

If you let the bike warm up for a while with the choke on, will it then come down off the choke with both cylinders firing ??
 
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