2 questions

1. Depends on the time of year and what kind of blades you're running on your harnesses. colorado blades will run better at lower speeds and I tend to run a little slower early in the spring (1.5-1.8 mph - gps) as the year progresses, the water temps rise and fish become more active, I troll between 1.8 to 2.5. willow blades run most effectively starting at 1.8 mph I found.

2. It depends, but I found that overall, the dipsys outproduce...some days though, for whatever resaon, the riggers will match if not outproduce the dipsy although being rare.

Tip: If running your riggers and you mark fish with nothing happening, try popping a rigger rod and letting the lure flutter up....you will find this often triggers following fish to strike. The last time I was out, I ended up doing this every 15 mins. or so and caught a walleye almost every time.

3. My guess would me crawlers trailing a watermelon harness
seriously: My guess would be emerald shiners (I think I know where you might be going with this)

4. Start trolling the N 8 to 10 line straight out of Conneaut harbor....if you can't catch 'em, take up golf

Hope this helps.

what shutupnfish said has been about the key this whole summer... wait for a response from kingnuke if he sees this

1. A good trolling speed for worm harnesses?

2. Dipsey or downriggers?

The reason I ask is today is the first time I have ever trolled for Walleyes. After fighting the downriggers (first time user) I got them to work some what. Seem to be a lot of screwing around as compared to the Dipsey I tried. Of course, no fish but a great learning experience.

Ok, a third question. What is the main food source for Erie Walleye?
 
#1- Harness speed is dependent on blade type, willows will spin as low as 1.5 but there design is made to allowed to be spun at higher rates of Speed as Paul said. I prefer 2.0 minimum with willows up to 3.0 depending on H2O temperature. Colorados will spin at 0.5 mph great for early season or cold water apps, althought it has surprised me how many guys have been fishing them this summer in the 1.5-2.0 range and having success, big colorados that is.
 
#2 Dipseys will shine especially on flat calm bright sunny days as Eyes are boat shy and when there isn't that eye chop it seems they are skittish of the boat even in deep H2O. But as we saw this past Friday on calm days the weighted Cranks off the boards blew away the dipseys and produced bigger fish. Riggers are good in certain situations but not a necessity for eye fishing on Erie.
 
#3 Main food source is dependent on time of year and where(depth of H20) the eyes are. Right now the deep water eyes are gorging on smelt, and getting there fill of Emeralds as well, they do eat perch and we have found white perch in them as well. In shallow we found a ton of Gobies in the eyes bellies especially early in the year. We also found some of the precious steelhead smolts  in bellies this spring.
 
 
Best thing I can tell you to increase your success is get out on a boat with someone who knows the lake and learn from them. Fish on a few boats, everyone does things differently and there are many ways to put "These Dumb Fish" in the boat  .

Thanks too all. I am going to get back on the water this weekend and try again. Sooner or later I will figure this out just like I did with the bass.