Rowlingstone Introduction and gas gauge problem

Hi guys I am a new member now. I have always loved motorcycles even when I was 9 and got my first mini bike, thats when it started. Ive had many bikes since then and now I have a full dress Harley electraglide a Goldwing, a couple regular 150cc scooters and my newest bike a 2003 Honda Silver wing FSC 600. I love the ease of the step through bikes now that I am 65 so its a lot easier than my Electraglide to back out of the garage and get pointed in the right direction ha ha. They are all easy to drive but maneuvering them when they are turned off into different spots seem to be the hard part. Anyway the gas gauge was blinking on my new silverwing so I went to fill it up and it was already full. I figure the sending unit was not working good but ive never worked on the silverwings yet so if there is any good advice I would be thank full. Does the sending unit come separate than the whole fuel pump unit and its in the tank im sure so let me know,in the past I have cleaned up the electrical slider the float controls on other vehicles but I dont know about any of it yet. Is the tank a lot of work to get to ? can you pull the assembly out of the tank without removing the tank?  Of course I am waiting for the complete shop manual to arrive which I always get when I buy a new bike but its a week away still. So I know there is a lot of good info out there with all you guys so I look forward to talking to everyone,( once I figure out all the post it rules and how to's) thanks guys.   Randy

Hello Randy. Welcome to the forum.

It sounds as if you’ve got gunk & varnish on the sending unit coil/wiper. While the real fix is to remove the pump/sending unit (yes, they are one assembly), the more practical approach is to use Techron or Seafoam treatments to the fuel tank. Think one bottle of Techron over the next 3 tanks full for starters.

The tank drops out from the bottom which, unfortunately, necessitates removing everything forward of, and including, the seat. Meanwhile you could remove the seat undercover to expose the fuel pump/sending unit plug and check do a voltage check. The pump is 12 volts, the sending unit is 5 volts.

Please keep us posted. We all benefit from shared information.

Tim

Yes the fuel sensor is attached to the fuel pump unit in the tank. I have a brand new unit in mine and the gauge does not go below full until about 46 miles. Just let you know. Maybe I just over fill it?

One other thing: When you turn the ignition ON does the fuel gauge sweep to FULL and then drop to flashing? If it does then that it indicates that the Combination Meter display is good.

If it doesn’t then you should access that 4 pin terminal at the fuel pump and jumper the 5 volt (Sending Unit) connection to see whether that moves the fuel gauge. Be very cautious, the other connections on that 4 pin terminal are 12 volts. Applying 12 volts to the Sending Unit circuit will allow the magic smoke to appear at the Combination Meter and/or toast the Sending Unit


Edit: The wiring color codes for the Sending Unit are, Gr/Bl and G/Bl.

Until the manual arrives, try this;
https://manuals.wotmeworry.org.uk/Honda/Honda%202002-2013%20%20Silverwing%20600%20Service%20Manual.pdf

Welcome aboard this board Randy!

Welcome aboard Randy to the BEST SWing site on the net.

And like Tim said, try techron or seafoam first. It might just be gunky. I use seafoam especially when I put it away for the winter. I usually dump 1/2 can in the tank and fill it full. Then I take it for a few mile ride to make sure it's circulated nicely. Never had a problem with it. It wouldn't hurt to also do that for the first few tanks even/if the gas gauge starts to work properly. It will make sure all the gunk is gone.

I also use it in my snowblower and lawn mowers. I dump 1/2 can in my 5 gallon gas can and fill that up. Sometimes it takes 2-3 years to use it all but no problems there either.

Dale N. wrote:

... snipped ... I use Seafoam especially when I put it away for the winter. ... It will make sure all the gunk is gone. ...I also use it in my snowblower and lawn mowers.

^^^ This! ^^^ I use Seafoam in all of my engines including my truck's diesel engine. It is the best degunker/decarbonizer and fuel stabilizer I have found over the years. And it will not hurt your engine! Go to their website and check out their videos.

When you have the fuel pump assembly out you can clean the tank fairly easily. Reach in the hole, break cleaner and a rag gets the varnish out. I had to replace the whole fuel unit and wash the black tar out of the tank when I bought my SW that sat in a garage for 10 years.

No doubt about it, SeaFoam is the best there is! imo, Paul

Look inside tank with a good flashlight . Rust-gunk???
( Think one bottle of Techron over the next 3 tanks full for starters. Quote. ) 1 ounce per gallon of fuel.
Techron can remove junk on sending unit slider but not a overnight fix.

Mech 1 twa wrote:

Look inside tank with a good flashlight . Rust-gunk???
(  Think one bottle of Techron over the next 3 tanks full for starters. Quote. )   1 ounce per gallon of fuel.
Techron  can remove junk on sending unit slider but not a overnight fix.

Agree but one other thing makes it work more efficiently and that is run the tank level down to at least 1/8 of a tank before the next treatment, better wait until the reserve bars are flashing. Reading the bottle instructions you will see UP TO xxx gallons, adding the entire bottle won't hurt.

[quote="Cosmic_Jumper"]Hello Randy. Welcome to the forum.

It sounds as if you’ve got gunk & varnish on the sending unit coil/wiper. While the real fix is to remove the pump/sending unit (yes, they are one assembly), the more practical approach is to use Techron or Seafoam treatments to the fuel tank. Think one bottle of Techron over the next 3 tanks full for starters.

The tank drops out from the bottom which, unfortunately, necessitates removing everything forward of, and including, the seat. Meanwhile you could remove the seat undercover to expose the fuel pump/sending unit plug and check do a voltage check. The pump is 12 volts, the sending unit is 5 volts.

Please keep us posted. We all benefit from shared information.

Yes I will try the seafoam first, the gauge seems to work well it goes all the way up when turned on then down to 1 and blinks. I am not ready to tear it all down yet so I will just watch the miles for now and try the seafoam or techron first and see how it goes for awhile. Thanks for all the good tips !

Well the first thing I will try is using the techron or seafoam first as I am not ready to tear it all apart just yet, I will watch the mileage and run it down to almost empty a few times and add the additive and see what happens, Then if I have to I will buy the unit and install it. The gauge does go all the way up before it comes back down and then settles on 1 bar and blinks so im sure its the sending unit. I will try the techron first and see how it works over a few tanks of gas. Thanks for all the tips, lots of good info out there, thanks!