Just above idle is where the a/f screw and slow (pilot jet) area of the carb circuit work, so you may have some issues with either or both. Are you running stock exhaust, intake and carb jets, or do you have aftermarket stuff on? Also, is you air filter clean? Check all of those areas.

 

The bike as the factory stock muffler, and carbs. I checked the air filter, and it's clean. I have the VTX service manual, but I'm having problems locating the A/F screw....is it the same as the pilot screw? Can someone provide a picture of it? The manual's description on its location is vague.

 

The bike as the factory stock muffler, and carbs. I checked the air filter, and it's clean. I have the VTX service manual, but I'm having problems locating the A/F screw....is it the same as the pilot screw? Can someone provide a picture of it? The manual's description on its location is vague.

No, the a/f screw is separate from the pilot jet. In this picture, my a/f screw has been changed out with an aftermarket one (the knurled thumbscrew with the white dot on it). The stock a/f screw is up inside that hole, and you need a special "D" shaped tool to adjust/remove it. Some have taken a spent bullet casing and dented one side to make the tool. You definitely need to get the carb popped out of the boot and tilt it up to see it.

 

I'd try add 4oz of Seafoam to a tank of gas. You may have a clogged slow jet. Don't Russ to get the Seafoam out of. The seafoam need time to work.

Doug

 

With a carb you need to be careful what kind of gas you use. Any ethanol can cause a clogged jet. Many times when I have come across this type of problem it was necessary to rebuild the carb, or at least take it apart and get whatever is clogging the circuits. My favorite tool for clearong the circuits is a bread tie with the plastic or paper removed. Not the easiest tool to use, but after pushing it through the passages you know they are clear. Be sure to get the ones in the area where the butterfly closes, as this is where a lot of clogs occur. Good luck.
Don

 

Check the needle slide boot on top of the carb for holes or splits. You might have to stretch it just slightly to see them.

 

With a carb you need to be careful what kind of gas you use. Any ethanol can cause a clogged jet.

Been running E-10 in my bike since I bought it new in Sept 2007...I now have 37,000 miles on it, and have yet to have ethanol clog up a jet....And as far as that goes, been running the same E-10 gas in all my vehicles for at least 20 years, as that's all that's available in my area, and no carb problems or any other kind of problems due to E-10 gas...Waaaaay too much wrong info floating around about ethanol in gasoline these days...

 

Loose line around Carb.

Ok, guys. Thanks for all the help...upon further inspection of the Carb area I found this line disconnected. I believe it's a vacuum line. Can anyone provide any input. I think it needs to be connected to a male-piece deep in between the cylinder jugs. Problem is, it near impossble to get any control of the hose to fit it back on the male-end piece.

 

That looks like the crankcase vent hose from the front-top-left cylinder head to the air box.

The manifold vacuum hose is on the left side of the manifold and not in the photo.

One other hose going to the airbox is air for the PAIR valve.

 

That looks like the crankcase vent hose from the front-top-left cylinder head to the air box.

The manifold vacuum hose is on the left side of the manifold and not in the photo.

One other hose going to the airbox is air for the PAIR valve.

Thanks. The natural direction/length of the hose makes me think it attaches to the back side of the Air Intake port (there is no hose connected to it at this time). Service manual page 5-20 shows the front side of the port. When I turn the engine over, air blows out of the loose-hose. Does the "back side" of the air intake port, receive pressurized air?

 

[HR][/HR]http://www.vtxcafe.com/showthread.php/57521-Airbox-Breather-Tube-(aka-OIL-LEAK!!!)

 

Ok, thanks guys for all your input. Now I just have to figure out how to get the crankcase breather line onto the Airbox connection. There is very little room to work in, unless you takeoff the seat, tank, and loosen the airbox. My next question, since this all stems from the bike running poorly in the lower throttle settings, (slightly above idle throttle position) would the crankcase breather line being disconnected cause this poor running performance?

Thanks Again!

 

Ok, thanks guys for all your input. Now I just have to figure out how to get the crankcase breather line onto the Airbox connection. There is very little room to work in, unless you takeoff the seat, tank, and loosen the airbox. My next question, since this all stems from the bike running poorly in the lower throttle settings, (slightly above idle throttle position) would the crankcase breather line being disconnected cause this poor running performance?

Thanks Again!

No it will not have any affect on the running of the engine.
rais the rear of the seat up with a block of wood or stick and you should have enough room to pull the airbox out enough to connect th hose back on.

Doug

 

No it will not have any affect on the running of the engine.
rais the rear of seat up with a block of wood or stick and you should have enough room to pull the airbox out enough to connect th hose back on.

Doug

I think Doug meant raise the back of the tank, not the seat. That hose is a booger to get onto the stock airbox. And, it will not affect the bike's performance. It just empties out any blow-by gunk from the front cylinder into the bottom of the airbox.

 

I think Doug meant raise the back of the tank, not the seat. That hose is a booger to get onto the stock airbox. And, it will not affect the bike's performance. It just empties out any blow-by gunk from the front cylinder into the bottom of the airbox.

yep! Thanks , one finger typing on my ipad. I'll edit it.

Doug

 

Ok, thanks guys for all your input. Now I just have to figure out how to get the crankcase breather line onto the Airbox connection. There is very little room to work in, unless you takeoff the seat, tank, and loosen the airbox. My next question, since this all stems from the bike running poorly in the lower throttle settings, (slightly above idle throttle position) would the crankcase breather line being disconnected cause this poor running performance?

Thanks Again!

That hose come off by itself? When was the last time anyone had the airbox off and does it match the timeframe of the bike running bad just off idle? Am thinking outloud here...

Stumble just off idle might be caused by a vacuum leak, check the smaller diameter hoses while your up in there.

 

That hose come off by itself? When was the last time anyone had the airbox off and does it match the timeframe of the bike running bad just off idle? Am thinking outloud here...

Stumble just off idle might be caused by a vacuum leak, check the smaller diameter hoses while your up in there.

I'd like to think the engine performance and crankcase breather line are related. I rode the bike all summer with no issues...It wasn't untill recently the bike started to hesitate when you were at a throttle position "slightly above idle." I'm the second owner of the bike, and I'm not sure if the prior owner took the airbox off. I personally haven't had the airbox off; I've opened by the airbox to inspect/clean the airvfilter.

 

I'd like to think the engine performance and crankcase breather line are related.

They're not -the crankcase breather will have nothing to do with your stumble. A lot of people, myself included, have routed the breather off the airbox entirely with no problems. More likely a cracked vacuum line or intake boot - something along those lines. It's also possible that you have a cracked wire at the ECM - that can mimic your problem as well.

 

2009 with3500 miles.

I would lean toward fuel issues. Something has clogged a jet/air bleed. MR VTX CARB 101 to clean and inspect.

Verify fuel flow from the petcock. Apply vacuum and the gas should pour out of the hose. Remember it is gravity flow, just a good stream.

I do not remember of any VTX breaking the ICM green & black wires at that low mileage.
Intermittent spark = backfires, poor performance and usually it stops running altogether when the wires separate. The insulation shrinks as the wire is pulled apart right at the ICM connector.
The two most forward wires on the ICM.

 

Is your accelerator pump squirting gas into your carb when you twist the throttle? Remove air cleaner look into carb, twist throttle, there S/B a stream of fuel shooting into carb. Clean that jet and problem S/B gone.

 

No offense but 8 year old thread…wanna bet its fixed….always check date of first post and last post to see if its still active….good luck