Beginning to think I have a FrankenRude. Had to order a replacement impeller that is made for '79 thru '88. Got that installed and mounted back. Now I'm curious as to what this thing is. It's mounted in the same area as the choke would be but no levers etc. just some tubes going to the carb setup. I've looked at diagrams on marineengine .com and cannot find anything like it. Thinking maybe a vacuum setup? the red lever turns forward for whatever reason.
Wondering if a PO changed the transom mount bracket that has the '78 tag on it.
That's a primer solenoid. When energized it uses fuel pressure to squirt fuel directly into either the carb throats or in many cases into the intake manifold, for quicker starts. Plus you don't have the restriction and cost of a choke mechanism sitting at the front of the carbs' throats.
The red lever is for manual operation of the primer. IIRC you'd turn the lever 90-degrees to manually open up the primer. Of course you'd have to shut it off after the engine starts, otherwise it'll continue to pump extra fuel into the engine.
That is the normal running position. You might want to consider an update to the top cover #437228. It comes with a better cover (a little thicker, they cracked easily & leak) & ethanol resistant gasket. There is also a maintenance valve #175158 that can be added. It is a schrader valve that you can put fogging oil in or engine tuner/power tune. Just a convenient way to add it to the engine without removing the cover. Just check for a fuel leak in this area when you pump up your primer bulb.
I can't believe you didn't know what that is. I have several of those spray hoses in my stock. I don't know if the hose assembly will fit all brands of fogging oil or just the OMC can and some random selection of others.
Regarding the update kit, there is no hurry to fix what isn't broken. But the cap & gasket do come as a kit.
Jim, it's the newest OMC I ever had
I'm so used to fixin' the classic 50s and 60s when I came across this '78 I was scratchin' my head but thanks to you guys now I know. The dumbest question is one you don't ask.