2003 T/S Top Gun starting issue
 

Hoping someone can help as I am out of ideas. Twin 575 SCI's just rebuilt at Innovation. Both motors run good with no issues. Problem is when starting. Start one and let idle. When go to start other, sometimes it will kill running motor. Does not matter which one I start first. Does not matter what the battery position is on. I am having a hard time isolating batteries to individual motor. Even when disconnect large ground from between motors, and have battery switch set on 1 for port and 2 for starboard, when go to start non running motor, I can see voltage drop on running motor???? Change batteries, same issue. Both alternators are putting out 14 vt. Checked all grounds. Both starters turn over quickly and each individual motor will start immediately. I am sure I am missing something. Ideas?

Thanks in advance.

Ed

Did this issue just start ? new boat to you ? sounds like voltage is being pulled from the ignition system on the running engine when trying to start the other one

I'd be on the phone with Innovation like this, :D

https://cimg8.ibsrv.net/gimg/www.off...82b1009b4f.jpg

Yes, this just started after I installed. This is not an Innovation issue. I pulled motors, they rebuilt and I installed. Started then. It has got to be something on install but I can't figure out. I have pulled and installed dozens of motors in Cig's so it has me baffled. Agree on voltage drop. Will keep trying to find.

Ed

Id check the voltage on both batteries at idle, meaning no load, where do you have the ground cable from the batteries rear stud on the bellhousing ?

I had a stud connection to bell housing not clean enough because engines were repainted after rebuild once. I had to sand around stud, apply dielectric grease and reassemble. I know it sounds simple, but many times it is.

Yes, on stud at bell housing. Innovation did just about powder coat everything. I will check. Thanks

Ed

Have you tried it with both batteries to #1 ???

On my AT, #1 on each switch is the primary battery for each engine. #2 on each switch is for the other engine's battery.
If I have one switch on #1 and the other on #2, they are both using the same battery.

Not sure how Cig wires their batteries and switches.

My Cig is also wired this way.

Interesting. This is my second year for this Gun. I always ran all switched on both and never had this issue until installed motors this spring. I will try both on 1 and see what happens

Thanks.

Ed

Wouldn't it be great if it was something that silly and simple

Did you find a solution here? Interested for my own education.

I am interested too as I am having an issue like this also.

I always ran my TG with both battery switches on 1. That isolates each battery to each engine. I would only switch to both to start when a battery was low from running the stereo for hours. I also had a ground between the two engines, but have seen others without. Good luck, electrical issues suck!

I went through a problem with having a battery go bad recently, at least it turned out to be a bad battery.

Try to start the port engine and all I get is a click (this is with each engine on it's own battery, as in both switches pointing to 1). I switch the port engine to battery 2 (which is the stbd battery - I double checked the wiring and this is correct). Still just a "click" of the starter solenoid. I start the stbd engine, which readily cranks over, and try again to start the port engine, still just a "click" or maybe a "stuttering click". I double checked all power and ground cables, all good. I am now convinced that the starter had suddenly gone bad. I just couldn't believe that was the suddenly the problem, so I swapped batteries and the problem swapped also, now the port would fire right up (Great, at least the starter isn't bad), but the stbd just clicked and it didn't matter what I did with the battery switches. I then came up with the idea to run a jumper cable from one engine to the other, as a ground to ground, and suddenly my problems were gone. Everything worked as it should. I still cannot believe that all of the battery grounds are not combined somewhere, but evidently they are not.

Long story short, I ran a ground cable from engine to engine and now my battery switches work as they should.

if you switch a battery selector to another engine or battery without having the blocks tied together you dont have a complete circuit, glad you got it fixed much easier than changing a starter

I used to run a negative cable between engines, with EFI it didn`t seem like a good idea so I disconnected it . (interference, backfeeding etc )
Haven`t noticed any ill affects

I can tell you I have a ground between motors. Still struggling with this as it is quirky. Been using boat every weekend and runs great. Just sometimes when one is running and trying to start other it will pull running motor down. Both motors are running on #1 selector switch. If I start both at same time, no issues and they will both immediately fire up. I will eventually figure it out :)

they only thing the perko switch does is switch +12 vdc from one terminal to another, so If you switch engine 1 to battery 2 where is the return, engine 1 has the negative of battery1, if the engines aren't tied together I dont see how it completes are circuit.

Negatives on all my batteries are connected together so it completes the circuit. My engines do not have separate ground cable connecting them.