Just finished install on 525 SC. Timed it. 19degrees at idle and 35 degrees at 4500.

The motor has a hard time starting, backfiring, cranking forever, flooding. Took it to the lake yesterday for first run to try it out and as soon as I put the boat in gear it sputters and dies, even when trying to throttle up. Had to get towed in.

So far my plan is to get a vaccum gauge and play with the idler screws. Are there any other common things to adjust to help these carbs out?

What jets should they have ? I've read 98s?

​​​​​​Any info would be helpful since there isn't a ton online for 525scs. Thanks!

Why are you @ 19* base timing ?

That's what I read to set it at. What should it be?

Timing looks good, one degree more advanced than OE. I can't help with jets because mine had 850's on it. But jets do not play a role in starting, idling or throttle tip in. Not much to actually adjust, float levels while idling and idle mixture screws.
On a new install start with the basics, check plug wires, possibly a vacuum leak
Some more people smarter than me will chime in

What timing advance system does it use ? not really familiar with this engine, but most BBC are timed around 8* at idle

More base timing than advance timing that seems weird, but learn something every day.......have you double checked the firing order , wires in the correct place,

So a search under my name and 525SC's, about 93 million years ago , when the dinosaurs roamed, I had redone a pair of these carbs and we had a good thread over this and the ignition timing.

When I had my 288 Sunny I put a 525SC in it. The previous owner fouled plugs left and right and it would not idle. I sent it to Dean Nickerson and he made his changes, reinstalled it, set the float levels and never touched it again. Never fouled plugs, started easily cold and warm and idled well.

Thanks! Do you happen to know what plugs it takes? I'm already on route to the parts store with my cap and rotor