depth finder help/ question about 1991 johnson 40 hp

[prosupermag]

I just recived a new to me depth finder it is a  lowrance LCX15MT that i am wanting to mount on my boat but untill i have learned to use the new one i want to leave the old one on the boat and that one is an older Eagle depthfinder  and my question is will the two interfere with each other if the transducers are close together on the back of the boat?  I also have a question about the GPS antena  i notice that on the bottom of antena there is an o-ring to seal it up but the rail of my boat is not wide enough to cover the whole bottom of the antena will this hurt the antena if it cant seel all the way  around the base or will it be ok?

I also have a question about my moter it is a 1991 johnson 40 hp  and when i had it out this weekend it would ocasionaly make a beeping noise out of the shifter/controle box does any one have any idea why this would be happening it has never done this before

thank you in advance for any help you can offer
Wade

[kenhuntin]

just for the sake of simplicity if they both work just use 1 sonar. lowrance is top shelf to eagle. the only effect to the antennae seal is a water intrusion into the boat. no worries about function unless you end up under water. A word of advice : do not ever get attached to a liquid crystal sonar. they are like buses and women a new one comes along every 15 minutes and renders the old ones obsolete

[The General]

In regards to the motor.  Do you premix the gas and oil or is it oil injected?  If oil injected the beep may be a warning the motor isn't getting enough oil.  Other then that I'm not sure. 

[prosupermag]

the moter is still oil injected and if that is the beep what do i have to do to get rid of the oil injection and go to pre mix on that moter 

and about useing only one depth finder i just want both of them on there for a few times on the water to make sure that my new used one is working  properly otherwise i will have nothing to compare it to