Side draft carbs

"I have a couple of 178 fireba

"I have a couple of 178 fireballs in my 62 Trojan one of these engines always runs "fat" or "rich" smokes, plugs are black but mostly dry.
Now all of a sudden this engine starts and runs "very smooth" Almost NO smoke at all, but at a high idle I let the engine run for 20 minutes. NO SMOKE! I cant believe it! But after i rev it a bit the idle settles back down and the engine is smoking again, regardless of RPM i have smoke.
I removed the choke plates long ago trying to figure this one out, Any Ideas?"

What is the timing doing. Soun

What is the timing doing. Sounds like it might be advanced initialy.

"Gerald!
Make sure the carbs

"Gerald!
Make sure the carbs are level if you have the 3 piece intake manifold loosen the clamps on the rubber donuts and push the front carb down toward the valley cover. and then retighten the clamps. What happens is when ever someone is climbing around on the eng they might have stepped on the top of the carbs and push the rear carb downward. that will throw off everything, these carb's are pretty sensitive to being level. I used to have the same problem with the 188 in my Lyman. What size is your Trojan 28-30 footer? Also you might want to check your exhaust hose. It might be collasping. When I first got my Lyman and put it in the water, every time I would fire up the eng. I would get black soot out of the exhaust. I had rubber exhaust tubes from the eng to the transom. and they layed in the bilge.I pulled one of the hoses off the eng and they were all sooted up on the inside and the inner lining was collasped. I ran the rest of the year that way and in the winter I replaced the exhaust with solid 3" type L copper pipe and fabricated elbows from factory 45's and silver soldered all the fittings and put in 2 expansion joints on each side. The boat ran better and no soot, and smoke. You may have the same problem also.
I hope this might be some help.
Fred Durbin"