Fuel pump

[nortstudio]

In doing some research before trying to figure out my low throttle hesitation/stumble, I found mention of the fuel pump. When I first got the bike, the PO showed me how to turn on the run button and let the pump do it's thing, and then hit the starter button.

I realize that today, I want hearing that sound it makes. I waited about the time that the PO had, but couldn't hear well because of traffic, and forgot about it. I was more concerned with my main fuse blowing. Now that the fuse thing seems sorted, I need to see if this pump is odd.

Is there a special fuse for the pump, or is that same as the ignition?

Would the bike fire up and run if the fuel pump is not firing up correctly?

Thanks in advance.

[sweekster]

It's a self regulating pump. If theres enough fuel in the lines to create the needed pressure you won't hear it when you go to start it. It also, if my memory is correct, won't be running all the time-only when needed ( I could be wrong though). I haven't gone through all your threads but it sounds like this bike probably needs either the carbs cleaned and synced or just synced. I say that a lot but it can usually solve a good amount of issues like this.

[DonTZ125]

The TCI turns the pump relay on to prime the carbs for 4 seconds as part of the power up routine; once the engine starts turning over the pump relay is on until 4 sec after the engine stops. As Sweekster said, even though the relay is energised the pump itself decides if it actually needs to run or not based on back-pressure from the float valves (the fuel level rises, the floats close the needles, pressure builds inside the lines and the pump shuts off until the fuel level in the bowls drops again).

If you're concerned that the pump isn't co-operating, attach a small hose to one of the carbs' drain port, run it to a small bucket / cup, open the drain screw and allow the carb bowl to empty. NOW turn on the switch, and listen for the pump.

[nortstudio]

Thanks folks. All makes sense. I was just panicked because the main fuses were blowing. Afraid I might have fried something.

The carbs are coming off alright. If this bike is anything like my other, the slow jets are clogged. Curious to see what these things are like inside.

I'll just need to find the adapters for my sync tool. I currently only have the 5mm brass plugs. I guess I can just bench sync until I get them. I'm sure it will be better than the way it's running now.

Thanks.

Scott

[nortstudio]

Are there suggested carb kits that you all like? I know with the older Honda kits, they sometimes lack in the quality control area. I'm assuming that it's best to replace all o-rings and gaskets on a carb clean, so I will need to wait until I have the kits to dig in...

[sweekster]

Are there suggested carb kits that you all like? I know with the older Honda kits, they sometimes lack in the quality control area. I'm assuming that it's best to replace all o-rings and gaskets on a carb clean, so I will need to wait until I have the kits to dig in...

I prefer this one:

http://fzronline.com/wiki/doku.php?id=synch_tool

[nortstudio]

Sorry, I was talking about rebuild kits. I already have a 4 gauge Emgo sync tool that I will use. I was just wondering if there were preferred rebuild kits, or ones to stay away from (keystar etc)???

[sweekster]

http://www.ebay.com/itm/4-YAMAHA-89-99- ... 500wt_1156

That guy seems to come recommended around here

[nortstudio]

Thanks Duane. Love your signature. I promise, I'm trying to search every chance I get