Back in high school (1974) I bought a 1965 Mustang. I learned to maintain and upgrade it using Chilton's manuals, reading popular hot-rodding, and asking fellow enthusiasts. Are there publications, such as Chilton's, for Cigarettes and/or Mercury Marine? I'm servicing my 1989 Cafe Racer and am running into a lot of unfamiliar territory. For example, what is this terminal block that goes to both batteries and has two low-current wires attached to it?

I`m going to say there is nothing like a chiltons for Cigs.
We`re your Chiltons
I pretty sure that is your parallel switch to combine both batteries.
There should be a parallel switch on your dash. 12v control voltage pulls in coil relay and combines both batteries.

between the 2 start buttons....???

Looks like a typical solenoid used to control high AMP circuit. functions the same as starter solenoid. Could also call that a relay too. The light gauge wires control the coil. Just google "solenoid wiring diagram".

Dan's correct, its your battery parallel solenoid. Some models don't have the switch on the dash, on my Top Gun it automatically pulls the solenoid in when you hit the start button or hatch.

Try and reach CIG3, he has the Cigarette manuals by model in PDF.

Top Gun, Cafe, Bullet Owners Manuals

Thanks for the info. That answers two of my questions; the other being what is does the PAR START switch do.

I've pulled up the cafe's floor, the Surveyor alerted me to a squishy portion. He said repairing it is a weekend job. Now that I have it out, how do I fix it? Stepping on the starboard side aft portion (typical boarding location) causes a wheezing sound as air escapes through the screw holes.

--AND--

What fuel additive(s) are recommended for Cigarettes?

I always used my parallel switch when I started my Cafe motors. They just spun faster doing that.

I use high quality 93 octane fuel so never bothered with any snake oils. Sometimes I would use stabilizer over the winter and sometimes I didn't. Never noticed a shred of difference, but I never ran the boat hard either.

I have a ton of Cafe stuff electronically if you would like it. Could send to you tomorrow - manuals, working diagrams, etc...... PM me your email address if you'd like it.....

Is it bad practice to mount a Honda generator in the engine compartment, venting the exhaust out the engine hatch vents?

Are you serious Clark?

CO is heavier than air , my boat has drains from cuddy to bilge , those openings could potentially carry the CO into the cuddy. if you want to do this while sleeping you may wake up dead.
When my gas tanks leaked into the bilge while we were sleeping the cuddy filled with gas fumes it woke us up and I felt like I swallowed a gallon of gas.
CO is odorless , you won`t wake up.

It's been done, but I would never recommend it.
https://www.performanceboats.com/thr....148330/page-2