WOT feels like not getting any gas

[MANA1]

Hi, wondering if someone has had this problem.
Carbs synchronized but still idles rough. Took her out for a test run after I synched the carbs.
Cracked open the throttle and took off up to 6500 rpm then nothing. It felt like there was no gas getting to the engine, just flat. New fuel filter and carbs cleaned and diaphragms all good.
I did notice the fuel pump kicking on longer wnen I first start her up. Any ideas?

 

[06VMAXIMUS]

Sounds like your fuel pump is the problem. I believe there are 2 rubber valves inside the pump which can be repositioned or replaced. Do a search here and you should be able to find some good info on it. And welcome to the VMF!

 

[jfeagins]

Here's the complete "How To" thread on that subject:

http://www.vmaxforum.net/showthread.php?t=8775

 

[tugla]

does the pump keep clicking everytime you turn the key on? even after it just ran? as mentioned could be those grommets moved and its losing pressure/prime. is this a new symptom or the bike been always doing this?

 

[MANA1]

The fuel pump only kicks on during the first start but stays on for about 3 seconds. The problem only started a couple of days ago hence the carb sync. I also ordered some carb joint boots since mine are cracked, would a vacuum leak cause the rough idle and loss of power WOT?

 

[MtnMax/Magniac]

A vacuum leak will definitely cause problems at idle, WOT depends how big the leak is.

 

[MANA1]

Couldn't wait for my carb boots to come in so I used a can of plasti dip to coat the rubber boots. It took about 6 coats to fill in all the cracks. Put her back together and now I got all my WOT power back. Its nice to see the oil light flash on as I hit 9,000 rpm. Got a older vmax? Check those carb joint boots, i'm glad I did. Ps.. tried the WD-40 spray on the boots trick to see if my boots were the cause of my vacuum leak. It gave no indication
that the boots were leaking. Just FYI

 

[SpecOps13]

I replaced 2 boots on my 89 the other day. 2 looked like the PO had replaced them. Cleared up a lot of my still existing
on again, off again problems. I used a propane torch, Un-Lit, to find that the 2 were bad.... Still got a float, inlet needle or
something screwing up once in a while...