MHZ Alligator 1250mm 49" twin outboard build

[RandyatBBY]

Looks like to me the boat is too far out of the water. Raise the motors till it settles.

[RaceMechaniX]

Have you tired any 3 blade props? An outboard guru was telling me the smoothest running happens with 3 blade props over 2 blades.

[Rich]

Looks like to me the boat is too far out of the water. Raise the motors till it settles.

Randy, if I go higher the props wont be in the water. I do agree that it was acting like I needed to raise them up. We will see what the new mount does.

Have you tired any 3 blade props? An outboard guru was telling me the smoothest running happens with 3 blade props over 2 blades.

No I have not tried 3 blades, what is the reason for them being better on an outboard? Any insight to this?

[Rich]

Well I tried the new mounts and it rocked pretty bad. These mounts were .5 inch down and about .375 back. I'm going to lift the motors from there and see where it stops rocking. On the other hand the boat planed out almost immediately and ran about 5 mph faster then before. Not to bad, the nose cone of the lower is below the hull so bringing it up .25 inch should put it just about the hull, we will see. I might try 50 and 52 mm props just to see if it helps with this configuration.

[Rich]

Well, I know its been a while since I posted this thread but I ended up finding you guys were right. The lipos needed to be way far forward to stop the "rocking" I was seeing. That being said I ended up making my own lowers in the hopes to run 12s reliably in an outboard here is a video on 6s:

https://www.youtube.com/watch?v=vPIUhatybe4

This is one of the first test. I ran the boat twice back to back at about 8 min per. I drained the oil (75W-140) I had in it and port side had water in it. I still need to figure that out. Let me know what you think. I did run these on 12s the time before this with a breather tube but all of the oil came out. Ill try to find the leak and fix that then try 12s without a breather tube.

[Rich]

Question for you guys. I was running the boat today and it ran perfectly. I am running 2 4092 700kv on 6s per side with x457 counter rotating (out) props. I want to see if I can gain more speed with the same 6s setup. I am currently getting 33-35 mph and would like to hit 45. I am thinking I should start with a larger prop but I can't seem to find any that are counter rotating besides the x465 (which I have on hand). I am not sure if the 4092s can handle that big of prop. I checked the temps on the motors today and they only hit 93F after a 8 min run pretty much full throttle the entire time. What do you guys think I can do to gain more speed with this setup?

[Bande1]

That's a super low RPM...stock zenoah type rpm. Consider 8s IMO...or even 10s. Under load you're probably turning 15-17k rpm. Go up in voltage, lower prop diameter, and raise pitch. I run 850kv on 12s on my 42" cat with 43mm props. It does very well like that.

This will open up way more props for you. I would use the prop calculator to find a prop for 8s or 10s that will achieve somewhere in the 50-55mph range. That's just me.

[Rich]

I was thinking about going to 8s. Since I'm using a gear drive I dont want to go past that. In short 8s might be all i need to do. Now i just have to find some 8s batteries.

[Bande1]

I was thinking about going to 8s. Since I'm using a gear drive I dont want to go past that. In short 8s might be all i need to do. Now i just have to find some 8s batteries.

I run these. priced pretty good. I pull 165A on them.

https://www.amazon.com/Socokin-Batte...zcF9hdGY&psc=1

[Rich]

I'm thinking 8s1p. It will be less weight and less wire. Thanks for the info though

[Bande1]

I cut my batt wires to 1" and add 8mm bullets. Then series connect with 1" of 10awg wire as a jumper. Keeps everything short and sweet. Just throwing it out there as a possibility.

[Rich]

That is an idea which I could always do. I do like the idea of having less weight though hmm... I think I'll balance and sharpen the x465s and do a test run and check motor temps. If that doesn't give better results then I'll save up for some 8s lipos

[Peter A]

Way back Tyler suggested 3 blade props. You also said there were a lack of L&R props. Have you bothered to check out what OSE and RC Boat Bitz stock? They both have two and three blade props in 50mm + sizes in both L&R.

[Rich]

Way back Tyler suggested 3 blade props. You also said there were a lack of L&R props. Have you bothered to check out what OSE and RC Boat Bitz stock? They both have two and three blade props in 50mm + sizes in both L&R.

Peter, I did not look at the RC Boat Bitz website because I didn't know it existed until now... What I meant was a lack of L&R props that were either bigger than the x457 that I am using or the same size just a different pitch. That being said will I gain speed going from the same size and pitch 2 blade to the same size and pitch 3 blade?

[srislash]

Peter, I did not look at the RC Boat Bitz website because I didn't know it existed until now... What I meant was a lack of L&R props that were either bigger than the x457 that I am using or the same size just a different pitch. That being said will I gain speed going from the same size and pitch 2 blade to the same size and pitch 3 blade?

not really. A little stronger out of corners but burn 1/3 more power is my experience. I may have a set of Old School Prop Shop props that I had Chris do up for me. I’ll look for them in the morning.

Shawn