Carburetor or Ignition problems?

[rileyroo]

 I have a 99 standard with 48,000 on the clock. Its been desmogged a couple yrs back. Its never givin me any problems until now. When cruizing @65 and rolling on the throttle some it starts to act like its choking or running out of fuel. It will eventually die if I stay on the throttle, . I usually let off and rev several times and it somewhat comes out of it. I ran a couple of tanks with seafoam thru and still get this happening. I changed plugs but the old ones looked good. I thought it was just bad gas but thats not the case. It seems to happen more after warmed up and maintaining steady pace on the road. I commute to work (4 miles) and it never acts up then. Like to see what you guys think. I'm not sure if its an ignition problem or carb jet problem.  I did put a petcock kit on during the winter months but I didn't check the screen in the tank. Plan on checking that today. Any input is greatly appreciated.

Thanks
Sik Valk

[PatrickDoss]

If you've got a spare key, try opening the gas cap next time it does it while going down the road.  Could be the tank vent is clogged.

[Udo]

I would at first check (better change) all vacuum hoses, specially the one to the petcock, the gas hose, and the vent hose from the tank. Maybe, one or more is defective....

[Ricky-D]

Too many things to check before you start to modify.

Sounds like a tank vacuum problem.

Jets nor ignition will cause the problem you report.

Make sure the tank vent hose is free and open.

[rileyroo]

I pulled the tank and checked the vent line and did find some crud around the "T" fitting. Cleaned them and blew air thru hoses. I'll check the one's on the petcock. I feel better about Ricky-D saying it can't be jets or ignition.  I've done all the work on this bike up to this point but not sure about digging into those carbs. Thanks for the input guys. Hope this fixes it. This is a great resource.

Thanks,
Terry

[98valk]

check the vacuum diaphragm if u are using the stock petcock. It wears out. installing a snubber will prevent it from wearing out.

my post on the subject
http://www.valkyrieforum.com/bbs/index.php/topic,3408.0.html

[Patrick]

This sure sounds like a fuel delivery problem, as some of the others have stated.. Check the tank vent line, petcock[again], vacuum line.. Pinched vent lines are very common when the tank has recently been removed..

[woody]

You dont say where you come from, but there have been a couple of threads where similar problems have been experienced by people in countries other than USA.
If you are in Australia and some other countries, it may be the dreaded foam in the airbox problem.
The guvment greenies have made Honda put smaller jets in the carbs, to fix the resultant performance problems Honda put a sponge packer into the airbox to restrict the air and subsequently make the mixture more rich.
You will see either the remains of the sponge or some left over adhesive in the top of the intake by looking into the opening. If you see this there is only two fixes.
1) rejet the bike to the 1.0mm main jets that it was designed for.
2) Fit a new sponge restrictor. Its the full width of the airbox, sits on top of the fins and is the length of the airbox.
If you are from the USA, it could be clogged jets, bad fuel or the peticock valve.
I had great help from all those in this forum to find my problem. Without their help I would still be thinking of selling the baby.

[R J]

Mud dobbers like to crawl in that drain hose and plug em up at the 'T'.

Heard of a couple that this happened to.