Hi Mate, Thanks, that’s a first, Outboard Wizard 👍 sounds like a better name than Aussie Boat Guy 😂 I like it. Really appreciate your support champion. Ps: your videos are amazing and what you do is inspiring. Everyone should check out DK the welder on RU-vid he’s awesome 👏 cheers 🍻 Aussie Boat Guy 😎
OMG!!! You are a true professional! I really love this stuff. I had a couple of out boards with nose cone, low pick up and hydraulic lift but nothing as beautiful hand made like this. I am stunned about your skills. Please keep up the good work. You know, people love to watch this technical/mechanical awesomeness for hours :)
Wow, thanks, that’s one of the nicest comments I’ve received and I really appreciate it. I have so much fun tinkering with that kind of stuff. All the best and cheers 🍻 Aussie Boat Guy 😎
very nice work. I especially liked your improvised home made counterbore tool for the drain plug, i'd have horribly over-engineered something like that and wound up spending a week on just the tool.
You're the man! Thanks for sharing this idea, with bobs nose cone kits going up in price, seems worth it to me to make a case like this being im an aluminium fabricator myself, and all the spare junk i have laying around lol. Going to be giving it a go with the old mercury tower of power 150.
Nice looking chopper you've got on there too. In America the SSM cases for little Mercs are very hard or expensive to find. This isn't a bad option considering buying one costs a couple grand.
Hi Mate, Thanks for your comments 👌 Yeah, those little SSM cases are awesome, love the little 15hp omc race lower unit too. Not sure mine would keep up, maybe 🤷♂️ would be good to make one for a 15hp and see the results. Cheers 🍻 Aussie Boat Guy 😎
Hi Mate, Yeah, I’m really happy with it 👌 I still need to find some time to do more testing, I’m hoping for more speed of course 😂 cheers 🍻 Aussie Boat Guy 😎
You could fill that drain plug hole with a weak polyester filling combined with micro spheres which makes the expoxy weak enough to sand smooth and then dig it out when you want to later remove the drain plug for an oil change.
Hi Champion, Thanks for your comments 👌 I had a lot of fun modifying that lower unit, I still want to spend more time on setup to squeeze more speed of course 😂 cheers 🍻 Aussie Boat Guy 😎
Love this job- so nicely done. I have tried to work out how the water gets to the pump from the front of the nose cone in the factory low water pick-up racing gear cases from mercury and can't see how they do it? With the after-market kits, like the bob's etc, they have an external hose running back from the nose cone but that's obviously not there on the factory ones. Can you explain? And what's the disadvantage, ie why aren't there more factory versions available?
Hi Mate, Yeah, the factory low pickup lower units just have different water tube setups inside the lower unit. They often have a vertical water shaft in front of the drive shaft instead of behind. The reason we don’t see more low water pickups from the factories is because they are not needed for the majority of boaters and a standard lower unit without the cone performs exactly the same when low in the water as a nose cone case. the standard case also doesn’t have the pointy cone poking out the front which is better for the standard boater too. Probably cheaper too without the low pickups. In saying all that, a lot of manufacturers are adding extra water pickups at the front of the lower unit bullet which I am loving. Cheers 🍻 Aussie Boat Guy 😎
Thanks@@25hpboatracerman , How do they get the front vertical water shafts in the lower units to mate up with the back shafts in the mid section? Are there channels wrapping around the drive shaft to get back there? And do you thing the noise from the high exhaust outlet is compatible with pleasant boating?
Hi Steve 👋 Cheers 🍻 Me too 😁, wish I had more time 😂 to get the 30d stuff organized. By the way, you are a big part mate of why I’m so into this stuff, cheers for all the help through the years. All the best mate Glenno
With the oil drain screw being recessed so far will that not create more drag through mini vortices forming than if the screw was flush with the external casing. I would experiment with another washer under it to bring it out a mm and solve your intrusion problem too.
Hi Mate, thanks for your comments and very well picked up 👌 I know it looks recessed in the video but it is actually nearly flush. I have seen that the omc race lower units that are a split case have a fair few recessed bolts in the lower unit that don’t seem to affect the performance. I do know that a protruding bolt or screw head does affect the performance for sure. if I was to bring my fill screw out a mm it would be slightly proud. When I was testing in the video I was using an old washer gasket and the new one is slightly thicker. thanks champ cheers 🍻 Aussie Boat Guy 😎
Hi Mate, thanks so much for your encouragement, it was a fun project and works really well. The guys who race boats in Borneo do it like that. cheers 🍻 Aussie Boat Guy 😎
You could just crush a copper tube and run it low, or built a channel into the skeg. Lot of work fora a 5hp mate but years ago we had a 5 hp race I used an old mercury 5hp green top 4 cylinder with a brass race prop . Got 2nd place as I was a kid and light , it kind of bogged for a couple seconds in the beginning of the race for I would have been 1st place 😂
Hi mate, Yep lots of work for a little motor but it’s a hobby, I find it so much fun to squeeze these little motors. didn’t know that Mercury made a 4 cylinder 5hp? I know they made a 4 cylinder that was a 25hp when they where white. sounds like you had fun 🤩 cheers 🍻 Aussie Boat Guy 😎
Hi Mate, You can just add the low pickups like in the video and assemble the lower unit as usual. Obviously if you modify the whole motor (porting, high comp head, big carb) it will perform even better. You can check out the other mods I did to that motor on the channel if you’d interested. Cheers 🍻 Aussie Boat Guy 😎
Hello. I am curious, can you tell me what, in your estimation, are some of the advantages and other considerations of doing this compared to just using a separate water intake pickup (hull mounted) and from there a flexible hose to a drilled hole in the gearcase where it can enter? Great video, thanks!
Hi mate, Well, for starters it is heaps more work 😂 than an intake on the hull and a tube. Advantages are it looks really cool 😁 also it is self contained so don’t need to add pickups on hull etc and can be swapped to other hulls without any need to drill more pickup holes in other transoms. Also if the water feed line from the hull to the leg splits or falls off the motor cooks. I have done gear-cases both ways and both work well to run the motor high. I am also happy either way. cheers 🍻 Aussie Boat Guy 😎
Most two-stroke exhausts are turned to produce power at certain revs, usually at the top end. How will the modified exhaust change the back pressure and thus high-end performance? Cheers
Hi mate, you are correct 👌 I have already made a custom exhaust tuner in the leg and actually wanted the outlet to be bigger for more flow at high rpm. it’s working a treat, just got back from more testing just now 😁 cheers 🍻 Aussie Boat Guy 😎
@25hpboatracerman The constraints to design an internal outboard exhaust system are not easy. That cone shaped expansion chamber on two-stroke race bike exhausts is designed to produce a shock wave to force back the intake fuel air mixture from existing the exhaust port. This is what makes two-strokes peaky with such a tight power-band. I knew a guy who powered a gyrocopter with an Evinrude outboard power head. He was a smart guy but could never get the engine to run right. The timing of the back pressure is critical to revs. This consists of getting the exhausted pipe length and expansion chamber cone angle and length as accurate as possible to the millimetre. Thanks for the chat. Cheers
Hi Champion. yep, you are spot on mate. Not easy in the trunk of an outboard to get the exhaust correct. But in saying that, you are talking about tuned pipes which outboards don’t go to that level of tuning unless in some outboard racing classes where they run external pipes. I have done a few test days now with the outboard and I’m very happy with the power (way more than stock) as I have modified the whole powerhead. I did put up a video on the mods a few vids back. Proper tuned pipes - like those on a two stroke dirt bike would definitely increase an outboards power with the returning sound waves forcing pressure back into the chambers but no room internally in the leg unfortunately. These motors will run (with more power than factory) even with a trumpet exhaust straight off the exhaust ports. Cheers 🍻 Aussie Boat Guy 😎
@@25hpboatracermanon the topic of tuned pipes I’d had experience fitting an expansion chamber to one racing motor, a 3.5 cc thunder tiger nitro outboard for an rc tunnel lol, but in all seriousness I’d say getting the total benefit from adding chambers would need ports to suit! Id think because these are ported for torque and quite low rpm’s! Id say the overlap and timing may not be well suited to pulse scavenging as well as a higher rpm port set? Id never measured port timing on outboards but it’d be interesting to mess with! Especially with a loose boat and big cleaver prop! The combined exhaust for multiple cylinders usually isn’t very effective compared with individual chambers or at these revs trumpets, the expansion chambers would have to be huge at 7k rpm but probably roughly half that size for 14k rpm
I’ve heard that some outboards are not self priming. That being said, I’m curious how does the impeller pick up the water if the water level is way before it. Does the impeller create an air vacuum?
Hi Mate, Very good question and I was worried about the same thing as I was making that lower unit. Knowing the racers in Borneo run their lower units like that I was happy it was proven to work. From my tests the rubber impeller does create a vacuum which is enough to draw the initial water up, once it’s full of water no probs. As you can see in the end of the video, it does draw water very easily when started which I was pleased. all the best, cheers 🍻 Aussie Boat Guy 😎
Hi mate, I always run the stock spark plugs or if I’m doing performance stuff sometimes the same plug without the resistor. Unfortunately I have not used Perma Gap plugs so don’t really have much input for you. cheers 🍻 Aussie Boat Guy 😎
Hi Mate, Normally just on the right side as that side is being pulled to the right by the propeller so more water pressure on that side. cheers 🍻 Aussie Boat Guy 😎
Hi mate, Unfortunately not worth it for the extra 1.8hp to buy and put on all the 9.8hp gear. you would need to replace the carburetor, the head. the cam on the stator and the stator stop. Even after changing out those parts I find it hard to notice a big difference between the 8hp and 9.8hp. cheers 🍻 Aussie Boat Guy 😎
