fuel gauge acting up

my fuel gauge has been working perfectly until about 2 weeks ago. when i turn the key on the bike will show the correct amount of fuel on gauge but then it will drop to empty. some times it seems to work ok. does the sender hook up to anything or does it go straight to gauge. i also took off the kerker 4 in to one exhaust i like the sound of the kerker but the stock exhaust is so much better. it just makes the bike run better and it is quiet. i have a 1982 yamaha xj750 maxim. i also found that i have a small oil leak more a seep coming from the center of the head where the cam chain pocket is. i guess this winter i will pull the head and install a new gasket and rubber seal. is there any other things that should be done when head is off. thanks bruce

 

fuel guage unit in tank is a variable resistor as the float rises and falls the resistance changes to indicate full empty. its connector is under tank green I think with 2 wires. check that it is in and tight . your tank sender may be cruded up inside of tank that may be where your issue is wait till winter to fix that. go old school and flip cap look inside tank with pen light. use trip meter to tell how far you have gone till you hit reserve.

if you are replacing head gaskets inspect cam chain sprockets and chain guides consider replacing them at same time as head gasket. would be a good time to do valve seals.
depending how deep you want to go possibly consider a valve job, cylinder hone ring replacement this would all depend on compression and leak down test results oil burning.

 

I'd want to be damned sure that the leak isn't coming from the valve cover gasket before tearing into the head.

 

i took off the exhaust and i can see where the oil is seeping. i will clean it real good first. i am not going to take it apart any time soon. its a small leak. i have to break the carb rack apart first and change the the shaft seals the number 1 carb has to have the fuel screw out 5 turns before the color tune is correct . the carbs are spotless i am wondering which is better 2 number 11 orings or the seals from here chacol

 

IMO the correct seals are the better choice. The o-rings cost a lot less though.

 

I agree, o-rings will work for a few years then start leaking again. Better to put in the correct seals and not have to do it again. I have tried the o-ring route.. never again.

 

i am going to get the seals.i see chacal sells OEM or aftermarket the price difference is $20 are the oem worth the extra money$

 

Not that I've noticed, but Chacal is very honest about that sort of thing if you ask him. He will not sell anthing that isn't worth using, and won't upsell just to make a few more dollars.