Bike acts as if it's running out of gas, but the tank is full.

[big bear craig]

This just started about two weeks ago.  The bike will be running fine and then all of a sudden it will start to loose power as if I need to switch to reserve, but of course the tank has plenty of fuel.  Also, to make matters worse if it runs too long when that condition hits, it will stop running and refuse to restart.  The bike has a pingel valve, and a Dan-Marc solenoid.  I have checked both of these for flow, checked all lines (except under the airbox) for cracks or leaks, but so far I have found nothing that should be keeping the carbs from getting fuel.  I also have opened the fuel cap while the bike is running, but that didn't make any difference.  The bike does have ignition,  the plugs are clean and almost new.  When it refuses to start, it will fire and run poorly if I engage the choke, but won't run long, and not without the choke. Where do I start to look or check?  The bike is a California bike, and has all the smog still attached.

[matt]

When mine did that it took a bit to figure out but what I found is fuel line got soft and would start to colapse causing not enough fuel.

[R J]

Ya had the gas tank off recently?

If so, your vacuum line has a kink in it.

[big bear craig]

Ya had the gas tank off recently?

If so, your vacuum line has a kink in it.

  Checked the vacuum line and no kinks that I can see, plus opening the gas cap doesn't seem to help.

[wild6]

Ya had the gas tank off recently?

If so, your vacuum line has a kink in it.

He means the vent line.

Edit: I see you understood that. 

Screen or filter clogged?

[Chrisj CMA]

This just started about two weeks ago.  The bike will be running fine and then all of a sudden it will start to loose power as if I need to switch to reserve, but of course the tank has plenty of fuel.  Also, to make matters worse if it runs too long when that condition hits, it will stop running and refuse to restart.  The bike has a pingel valve, and a Dan-Marc solenoid.  I have checked both of these for flow, checked all lines (except under the airbox) for cracks or leaks, but so far I have found nothing that should be keeping the carbs from getting fuel.  I also have opened the fuel cap while the bike is running, but that didn't make any difference.  The bike does have ignition,  the plugs are clean and almost new.  When it refuses to start, it will fire and run poorly if I engage the choke, but won't run long, and not without the choke. Where do I start to look or check?  The bike is a California bike, and has all the smog still attached.

Remove that Dan-Marc thing.........I believe several others have the same problem with it, it dont flow quite enough gas, and it doesnt prevent a hydrolock.  The only prevention is to shut the gas off and run the carbs out of fuel.  as long as there is gas in the lines and float bowls all the devises in the world in the "off" position cannot stop gravity

[salty1]

Remove that Dan-Marc thing.........I believe several others have the same problem with it, it dont flow quite enough gas, and it doesnt prevent a hydrolock.  The only prevention is to shut the gas off and run the carbs out of fuel.  as long as there is gas in the lines and float bowls all the devises in the world in the "off" position cannot stop gravity.

Boy, I sure want to hear from those who have had problems with their electronic shut-off valve! 

Big bear I would concur you have a fuel delivery problem. 

[designer]

Never had a problem with my Dan Marc.  But my quick disconnect caused me problems. Removed it and all is well.

[3W-lonerider]

been running an electric shutoff valve for over 6 years now..never had a fuel delivery problem..we run that same electric shutoff valve on gas diesel and L.P. gas on almost every peice of rental equipment our company has..only time iv'e ever had to replace one in the 13 years iv'e been there is the L.P. froze one up so bad it ruined it..you would'nt by any chance have that gas line running uphill at any point do you.

[sugerbear]

has it got a fuel filter? if so, dirty clogged too small?

[big bear craig]

Took the Dan-Marc off and even traded out the fuel rooster for another one I have, but that didn't help either.  This one has me stumped.

[wild6]

When you took out the fuel rooster, did you remove the white (light brown) plastic screen?

[Chrisj CMA]

A possibility.....if the vent line at the rear of the tank isint kinked I have heard on this board of people having the internal vent line clogged.  If you have the tank off try opening the cap and blowing compressed air up the vent and see if it flowes freely into the tank........(grasping at straws here)

[JC]

Had the quick disconnect, had fuel starvation issues when hot and/or early reserve problems. Lost the quick disconnect and so went the problem. Installed the Dan-Marc thing during my winter rebuild and now having a similar problem. The Dan-Marc comes off this weekend.   

[Patrick]

I agree that it certainly appears that you have a fuel delivery issue.. Have you tried opening the carburetor drains and looked at the fuel flow ?? From your posts it seems like you have a pinched/kinked or defective/soft/collapsing line..

[Chrisj CMA]

The other "sleeper" is unused vacuum nipple plugs that look good but are really severely cracked.  they can wreak havoc if not corrected

And Id also check the 18 screws that seal the 6 intake runners to the carburator connecting tubes

[big bear craig]

Ok I'm going to try the carb drains and check for fuel, I will also be checking the intake vacuum nipples, and all other suggestions posted.  I appreciate all the help.  Thanks.

[Tonysax]

Just a thought in a different direction. Does it have a stock ignition ? I had the same symptoms once. I had a Dynatek-3000 Ignition. The bike after a while would act the same way, it was loosing cylinders. I would shut it down and after 10 minutes it would be fine. It turned out the ignition module was overheating and not firing all the plugs. I put back in the stock ignition and it was fine. I replaced the Dyna with another Dyna and never had the trouble again, I keep the stock one in my bag.

[Fudd]

Never had a problem with my Dan Marc.  But my quick disconnect caused me problems. Removed it and all is well.

I've never had a problem with my Dan Marc/Pingle combo either.  It's had plenty of opportunities to starve climbing mountain passes pulling a trailer too.

[big bear craig]

Just a thought in a different direction. Does it have a stock ignition ? I had the same symptoms once. I had a Dynatek-3000 Ignition. The bike after a while would act the same way, it was loosing cylinders. I would shut it down and after 10 minutes it would be fine. It turned out the ignition module was overheating and not firing all the plugs. I put back in the stock ignition and it was fine. I replaced the Dyna with another Dyna and never had the trouble again, I keep the stock one in my bag.

It could be the ignition too.  I guess it's just going to be a process of elimination.

[Mr.BubblesVRCCDS0008]

If you have a spare key pop the fuel cap open and go for a ride if it runs ok  then your vent is most likely the problem. If you don't want to drive with the cap open take a straw and put under the cap and close it so the tank can vent thru the straw.

[big bear craig]

Tried riding with the fuel cap open, but no help.  I have checked all hoses, replaced anything that didn't look perfect including the intake caps.  I started it today and it ran fine in the garage, but when I rode  the bike I only got about a block away before it really started to run poorly.  I'm starting to think it may be in the ICM or something related.  Another area I'm going to check out is the battery.  I replaced the battery about three weeks ago.  She spins over fine so I doubt that's the problem, but I'm a believer in going back to the last thing that was done before the problem started.  Probably a long shot.

[CISE]

I was having similar (I think) issues a few weeks ago.

Would ride until about 2.5 gallons in the tank and it would act as if it ran out of gas. Top it off and it would run OK until the same fuel level.

I drained the tank and filled with fresh fuel. 6 tanks later no problem.

Try that perhaps.

[Mildew]

Mine used to do that until i made my petcock manual and closed off the vacuum line

[bscrive]

Tried riding with the fuel cap open, but no help.  I have checked all hoses, replaced anything that didn't look perfect including the intake caps.  I started it today and it ran fine in the garage, but when I rode  the bike I only got about a block away before it really started to run poorly.  I'm starting to think it may be in the ICM or something related.  Another area I'm going to check out is the battery.  I replaced the battery about three weeks ago.  She spins over fine so I doubt that's the problem, but I'm a believer in going back to the last thing that was done before the problem started.  Probably a long shot.

Sounds like you have a coil that is failing.  They will work ok when cold but when it heats up the coil either fails or works intermittently.