Suzuki Df6 issues

Just picked up a 2007 Suzuki DF6 for a kicker. She'd been lying around for a couple of years and the fuel in the internal tank had sludged up. I removed the tank and cleaned it, along with all the hoses and filter. I'm running some seafoam through her to clean things up internally and fogged the inlets too. She idles forever. She runs at high revs no problem. But doesn't want to respond very quickly. If I twist the grip too suddenly she dies. I have to ease her up to the higher revs. I don't have a manual but I think the ignition timing on this is fixed, so what else? Any known issues? I've heard of Suzuki exhaust ports choking up. Maybe something like that?

...one more weird thing. There's plenty of apparently clean oil in the sump. Glass is full and dipstick reads half-way. Absolutely nothing comes out when I remove the sump plug though...