420 DA Thread

Remind me tomorrow. I changed mine on the 420. The new one is a 6 blade model that is more efficient and quiet.

Jaybeaux
 
I have the same thruster on my 2005. I did the repair myself. Very easy. The two phillips heads in your picture are going thru the zincs, they are round. I have the pictures from 2016 when I was doing this repair. The pictures have model number etc if you like I can fwd pics to an email. For some reason I can not find the replacement part number for you. I think I used Florida Bow Thrusters. They were a great company to deal with.
 
I think I figured how to load photo


You can see the zincs in pic & the pin ( mine got bent) will come new with the blades
 

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@ASH and @Jaybeaux - thank you both so much for the information. I will preorder the zinc and blade and have this done during my next haulout! (I wonder if my diver can do it?)
 
Just to let you know my experience with this....my zinc had never been changed before and as such I could not turn the allen screws because they were seized. It required penetrating oil which I let sit for 48 hours before I could finally get them to turn (blindly) using a vice grip.
 
How many gallons of antifreeze do you guys run through each of your QSC500’s when winterizing them?
 
If my memory is correct it was about 6 gallons, but that was after I vacuumed out the strainer and filled with antifreeze first. That probably brought it closer to 7 gallons. Probably could have done less but it was worth the little extra knowing it was all the way through.
 
How many gallons of antifreeze do you guys run through each of your QSC500’s when winterizing them?
I just did this yesterday. My first time and went through 10 gallons after vacuuming out the strainer. Are you sure that was overkill but I wanted to be sure...
 
Thanks guy's. I did 6-gallons last year without vacuuming the strainer with no issues, But the slip the boat is in this year is so filled with leaves, I couldn't tell if see if the antifreeze made it out the exhaust ports.

Also, I use -100 antifreeze.... is that over kill? What product temp do you guys use for the engines?
 
Thanks guy's. I did 6-gallons last year without vacuuming the strainer with no issues, But the slip the boat is in this year is so filled with leaves, I couldn't tell if see if the antifreeze made it out the exhaust ports.

Also, I use -100 antifreeze.... is that over kill? What product temp do you guys use for the engines?
I used -60
 
Hi folks, has anyone ever tried running their 420 DA on one engine?
I had a problem with the starter on the port engine, thought I would have a go at getting it back to the marina from where I was moored… set off at crawling speed and after going round and round the mooring gave up, tied up.. and got a cab back instead.
I must have been funny to watch.. laughing just thinking about it.
Anyway.. is it at all possible, maybe at speed it may kinda go straight with the rudders on full lock?
 
It is possible. If I remember correctly, it takes about 30 Degrees of rudder to straighten out. There is one thing that I'm sure that other people will chime in on......if you are going on one engine for any substantial amount of time, I think that you are supposed to lash the shaft of the non-running engine. Otherwise, the prop "free wheels", and for a reason that I can't remember this is not good. Maybe because there is no cooling water to the transmission cooler? Someone will supply the answer.

Jaybeaux
 
Jay is correct, you don’t want the shaft on the engine that’s not running to spin because water is not running through the dripless shaft seal to cool it off and you’ll burn it up.
 
I had to run back 5 hrs on 1 motor a few years ago. Thank god for the autopilot. I would not want to hand steer in that scenario. My crossover cooled the shaft but never thought about the trans oil cooler. No issues with transmission fortunately.
 
Hi folks, has anyone ever tried running their 420 DA on one engine?
I had a problem with the starter on the port engine, thought I would have a go at getting it back to the marina from where I was moored… set off at crawling speed and after going round and round the mooring gave up, tied up.. and got a cab back instead.
I must have been funny to watch.. laughing just thinking about it.
Anyway.. is it at all possible, maybe at speed it may kinda go straight with the rudders on full lock?
I’m kind surprised that it wouldn’t track straight for you, we run on one shaft routinely when entering or leaving marinas and when caught up in slow traffic. It’s the only way I can get her under about 6 miles per hour without bumping in and out of gear. I have both motors to start but I’ve done it without one engine to start out. Full rudder for the first 25’ or so until i can get a little water going past the rudders, then 25 or 30 degrees works fine. Give it a try next time out. Practice makes perfect.
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Thanks for the responses.. yes an older 420 DA.
Yup as slow speed it just turns, and turns more than the rudders can counteract. Both engines are out right now, the boatyard mechanic and I are rebuilding them right now, the blocks have just returned from the engineering shop with liners in them. Should be up and running again within 3 weeks. Looking forward to having x2 new engines!
 

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