gas sending unit

I don't think you'll have to remove the tank. You'll definitely have to get the seat out of the way.

Here is a sending unit:
http://www.n3boatworks.com/catalog_product_detail.asp?cat=5045-91698&product=868468

N3BoatWorks offers a 10% discount to CorrectCraftFans.

Replaced mine a couple of weeks ago and was easy, no removal of the tank. Just have a small socket wrench to reach the back screw. Bought mine from nautique skins, fit like a glove, very close to original.

When the needle gets pegged to full when you take the positive cable (red) and make contact with the ground (black) while the ignition is at the on position, then you have a bad sender.

Good luck...

Sending unit, pink wire ( red ) to screw down post,comes from the gauge. Tank is grounded. with power on, at the gauge, should read full if pink wire is grounded directly to tank, not the post, indicating a bad sender, am I correct ?    

Correct, that is what I have been told.

Correction, reviewed my pic and yes it was a pink wire, not red. Sorry for the confusion.

Dellavalle wrote: Sending unit, pink wire ( red ) to screw down post,comes from the gauge. Tank is grounded. with power on, at the gauge, should read full if pink wire is grounded directly to tank, not the post, indicating a bad sender, am I correct ?

Dellavalle, please take a photo of how you are wiring it - not only will it help others understand you question but will also aid me as cant get mine working since removing the tank!!

gR@HaM wrote:    will also aid me as cant get mine working since removing the tank!!

Graham,
Is the tank grounded to the engine??

baitkiller wrote: 8122pbrainard wrote: gR@HaM wrote:    will also aid me as cant get mine working since removing the tank!! Graham, Is the tank grounded to the engine?? Pete, that is a different wire for a different reason. Dont confuse him.

Well, not exactly different. Temp senders and oil pressure senders work by being a variable resister to ground (the engine block).

Fuel senders also work by being variable resisters to ground, again the engine block. But, since the tank is not the engine block, it first needs to be grounded to the engine block. Well, if not the tank itself, then at least the outer ring part of the sender.

There does seem to be some confusion around grounding the tank for reasons of spark control while fueling, and grounding the tank (or sender ring/tab) for reasons of making the sender work.

That's why there is sometimes talk of being three wires back there. One is the sender wire. One is the ground that goes from tank to engine block and one is for the stern light ground.