All Activity

Hi everyone, Just wanted to introduce myself. My name is Wes, and I actually found this site ironically searching for a Cannon Digit-Troll IV downrigger / replacement parts. I am actually in Northern California, and I'm passionate about using downriggers for controlled depth fishing particularly for landlocked Sockeye Salmon (aka Kokanee) and just Salmon in general. Hoping to learn more from the members here on styles of fishing and approaches to apply back here in CA.

Well , you never opened it up and wonder why you're only getting 12 mph ? Seriously ? You could be right below the speed where the boat gets up on a plane and all you're doing is pushing water . Your tach , should be 1 - 200 RPMs ( with your normal load and gas level ) under the Mfg rated ones , which is usually marked on the valve cover , if you're propped correctly. No , pulling the prop is not going to allow you to count gear teeth. You have to pull the outdrive , mark both the drive shaft and prop shaft , spin the drive shaft 365 and note how many times the prop shaft turns with one turn of the drive shaft . Doesn't have to be precise , but should give you a ballpark figure of the gear ratio. Report back after you take it out , run it at WOT and trim the outdrive up to just below where it starts to cavitate . You'll feel or hear the RPMs going up at that point . Going to need the RPM numbers from that test ride . Yes ,3900 - 4300 rpms is the rating , 4100 + would be the sweet spot , below 3900 means you are lugging the engine , working it to death . Generally they try to have you running a 17 -19 pitch prop , so the drives are all geared for that .

I haven't put it over 3200 rpms. Was told not to run it over that but then I looked in the original owners manual and believe it says 3900- 4300 I believe. I'll measure the prop when I get home. Going to go out later and see how it operates at the higher rpms. I can't remember if the original outdrive had cavitation fins or not. The new outdrive has holes drilled for them. I can take the outdrive off and spin the prop or pop the top off and count teeth. I'm going by the sticker on the outside and specs based on mercruiser chart

What size is the new prop vs the old one ? How many RPMs are you getting at WOT ? Are you 100% sure the outdrives are the same ratio ? As in you've spun the prop / prop drive shaft and counted the rotations to at least get a idea that they are the same ratio ?