G'day Guys,

Last week I bolted one of these legs ( http://www.offshoreelectrics.com/pro...prod=OSE-80980 ) to one of my F1 hornets.
My leg is a bit different from the one pictured on the OSE website. ( Different motor mount and an extra brass fitting.)

After some mucking about setting up an acceptable pushrod setup (600 heli ball joints/pushrods and some modified nylon control horns) I dropped her in the dam last night.
Power was great, motor stayed cool and battery/esc temperature was ok. Things were going great for a few minutes, and then I lost drive when the flex snapped.
I launched my inflatable and recovered the Hornet to find that the propshaft was seized solid. ( I'd lubed the flex before putting the boat in the water.)

I needed vise grips to liberate the prop shaft frop the screw in bush at the end of the leg. This bush isn't brass, and appeared to be "welded" to the steel propshaft. ( I've attached a pic, the bush looks like copper.)
With the inspection plate removed there appears to be a 'total loss' lubricant reservoir above the flex shaft, fed at the top with a barbed brass fitting and draining at the bottom with a small opening presumably to lubricate the prop shaft bush.

I've deburred/polished the inside of the prop shaft bush with some abrasive paste and my spare prop/flex shaft shows no sign of any binding.
I'm about to reassemble the leg to try things out again and was wondering if anyone else had played with these legs and had any issues.

I'm going to try some synthetic engine oil in the reservoir, is this the right method of attack? I've got a fair idea about things that fly ( helis, sailplanes, airplanes and multi rotors ) but I'm a newbie when it comes to boats so any advice is welcome.

I know a couple other people on here have bought them, but I haven't seen anyone else post about failures. Generally you want thick grease for boats, oil just washes away too quickly.

i am curious how many cells you are running through this... i am using a 3 cell setup, and the motor info on offshoreelectrics specifically states 2 or 3 cell only.

this is a video of my MRP running on 3 cells, running around 30mph, which is perfectly fine for this particular hull.

white tunnel ose (1 min 58 sec)

the video is the third or fourth run for that hull, i have a second hull, with an identical setup for motor, battery and esc, and it has been run twice, with zero issues like you describe. I have checked them once for grease, and found no need to regrease. once I have run them for a season, i will know more about their "needs", but i have not seen any abnormal wear anywhere in the drive train.

i am running a larger grimracer prop than stock.

if you are trying to get the most speed possible from this little unit, you might be trying to get too much out of it.

I'm sure you've seen this thread, but the original thread where all my tuning and testing was described is here:
http://www.rcgroups.com/forums/showthread.php?t=1702142

G'day guys,

Thanks for the replies.
I'm running on 3S and the unit is well lubricated.

I won't use oil in the reservoir again, as it does just drain away too quickly.

I hit a submerged rock not long before the initial seizure , so now I'm thinking I may have deformed the housing/bush by a few thou', which would be just enough to make it grab when it warmed up. ( It was a pretty big hit.) It started to get tight when I ran it yesterday with the polished bush and new shaft, I left everything to cool down, and it freed up. ( Not that anything was really hot.)

I'm going to try honing the bush before my next test.

Stretch1

Good info to know! I am planning on clamping one of these on the back of my outboard utility...
http://www.rcgroups.com/forums/showthread.php?t=1591892

the hobbyking hornet is also considerably larger and heavier than my MRP tunnel hulls, it weighs almost twice as much, and is 7" longer. you might be better off going with one of the larger "500" size outboards like the proboat motor available on offshoreelectrics.com http://www.offshoreelectrics.com/pro...rod=dh-PRB4020 I know it is considerably more expensive (twice the price if you include the cost of the actual motor), but it would be able to handle considerably more abuse than the little one.

I don't think the Hornet is that much bigger.... it's 29.5" with the motor.