Throttle problem in 85 Honda Shadow 500

[Wolfhound32]

Alright, this is my first post so bear with me !
I recently replaced the fueltank for my 1985 Honda Shadow 500 and bought a (clean) fueltank about 2-3 months ago.
Now recently I've noticed that on ocassion ( it doesn;'t do it all the time but once every so often, especially after I fuel up) I'm able to start the bike fine, drive about 2-3 blocks down the road without problems, and then all of a sudden my throttle will not let me accelerate any more; I loose all acceleration power ( and sometimes the bike will stall)

It'l do this for about 2 days or so off and on andthen it will drive fine again for a week or 2.

Now if my fuel line or filter was clogged I'd expect this problem more frequently, so that leaves me with WHAT THE HECK IS GOING ON ???

Any help will be appriciated.
By the way, i've drained my tank and the fuel is fine, there is no rust in the tank etc. etc.

Thanks for any help !

[Easy Rider]

Originally Posted by Wolfhound32

drive about 2-3 blocks down the road without problems, and then all of a sudden my throttle will not let me accelerate any more; I loose all acceleration power ( and sometimes the bike will stall)

Classic symptoms of a bad (plugged) gas tank vent. Since you have an '85, it is probably a "simple" in-the-cap vent. Do you still have the old tank? If it is the same kind, can you get the cap off of it?

If it is a different kind of tank, the cap may not be vented because it might be intended to vent some other way (vapor recovery system that you don't have). If that's the case, you may need to see a dealer for some advise.

In the mean time, don't fill the tank so full and when it happens, pull over and open the cap to relieve the vaccume in the tank. ***NOT*** recommended to ride with the cap open, however.

[Wolfhound32]

Thanks for the advise.
The new gas tank did have a "outlet" in the bottom of the tank which I thought couldn't possibly be the vent so I taped it up.
Maybe this is the vent however and I created my own problem.
I'll "untape" it and hope it'll do better.

thanks again though !