zmk1962

Well done Antony ! ... upsized as you went .... Cheers Zoran

Thanks Donna ... wasn't a hard decision to make they are entertaining ! .... and as a bonus it helps to keep the VicePresident of HR, Home Affairs and Finances happy with the boat 🤓 Cheers Z

Couldn't agree more KC ! ... thanks. Thanks Dieter ! ... Look forward to our next fishraider sesh guys when the warmer currents arrive ... hopefully with a bit more scale to show for the effort. Cheers Zoran

Idle at 1100 out of gear is definitely too high... on some other outboards you would not be allowed to shift into gear... 660-800 is where I have seen idle normally which ties into your takeoff in gear RPM. Sounds like your timing settings are off. There are settings that advance spark etc once you start to take off. Has any work been done on timing or on the timing flywheel recently? Cheers Zoran

Thanks Sam ... can't complain for sure. .... and I had 2 good eyes to see the action to boot. Cheers Zoran

.... and sips like a teetotaler .... Hahaha yes who would have thought such a thing existed ! Speaking from experience? Cheers Z

Hey Raiders, With the offshore action being reported as slow, and the water temp still being reported around the 17C mark, last Sunday I took the opportunity to take the family whale watching. So while we had no fishing gear on board, It was a good opportunity to test the 150HP 4st pushing the Haines 635L with 5 onboard. So net, we covered 136km on the water - launching at Ermington Warf for a scenic harbour run, and then chased whales up to Pittwater and back. I forgot to switch navionics off at the ramp, so it recorded the 15km drive home and shows 151km total track. The motor now has some 38hrs on the clock and has loosened up. Picking up holeshot and top end as expected. Offshore cruising was in the 25-60km/h range. As many of you know, whale watching should be renamed whale chasing - 30sec uptime and 5min down time - pop up anywhere ! So the day was spent cruising, idling, accelerating to the next spot. Overall consumption was 96.7L for 136km on the water : avg 1.4km/L or 0.71 L/km. So still no negatives to report - and still blown away by the 150HP beast pushing the 6.35m Haines. For those interested there's a short video below ... ignore my family's antics please ... Whales are just majestic creatures and seeing whales in their environment always brings out the adrenaline - so expect lots of ooohs aaahhhs and squeals of delight from the crew .... ! (suggest you watch in HD setting on youtube) Cheers Zoran PS - have to get a better camera set up ... gopro hero 5 is not cutting it anymore (1st world problem) !

Carbie or EFI model ? Cheers Zoran

Great stuff @DerekD ... paying it forward is an awesome endeavor. Enjoy your new skills @FishyMcFishFace and thanks for sharing. cheers Zoran

Lots of FG boats are on skids... and many folks are changing from rollers to skids 'coz of the lower maintenance. Just focus on correct support for now... and then on ease of riding on /off trailer. Cheers Zoran

By doing something like I have you are not changing the balance of the trailer ... the wheels can stay exactly where they are. You are just adding support to the transom. The boat is already balanced where it is, its just using the hull to carry the load, rather than the trailer. Cheers Zoran

In my experience that is too much overhang. The transom is carrying all your motor dead weight. Ideally you want a roller or some other trailer support just under the transom or as close to it as possible. The way yours is set up, the weight is carried by a section of the hull. If there is a stringer at that point, then all may be good. If not, then it's essentially the ally or fibreglass skin that is carrying that weight. It will flex and eventually fail (crack). I have a very similar boat with pod / trailer set up. This is how far my trailer extends... but note the rollers that are pretty much under the transom providing support. Cheers Zoran

@Fab1 has an unpainted ally boat that looks shiny new in every photo he has put up ... maybe he can pitch in or you can PM him. Cheers Zoran PS - if you search the forums there are other entries discussing this ...

Great report and top effort. You’ve really got into the swing of this sport - congrats! I can see you offering guided tours of your spots in the near future! 👍💪 Cheers Zoran

I had a few minutes after lunch so located it for you... download the PDF from this link: http://www.hedges-uk.com/boat/Merc/outboards/2-stroke/2-stroke/70-75-80-90-100-115/70-75-80-90-100-115.pdf Cheers Zoran

@Blade can you get your hands on a service manual for your motor? Ignition wiring diagram would be most helpful. if you can’t find a manual- suggest you google search an online spare parts store for your motor. The US ones often have exploded views and diagrams to help you choose correct part. But you can use the diagram to help you locate / identify the ignition circuit. cheers Zoran

It can be used but depends on how often you plan to service your reel. Organic oils will cake up exposed to salt. You will get more longevity out of using products like inox or silicon based oil lubricants. cheers Zoran

Well you need to achieve planing speed as efficiently as possible. Determining prop size has 2 book ends: a) can your motor generate the torque from idle to spin the prop dimension fitted (diameter x pitch) to get you planing ASAP (holeshot) b) can your motor generate the torque with the prop dimension fitted (diameter x pitch) to get to WOT (max speed) The torque (twisting force) produced by a motor across the RPM range is typically a bell curve that peaks around 4000rpm. Typical motor idles at around 700rpm and has a WOT 6000rpm. At what speed does your hull plane - you can ask Parker?? For optimum performance you need to match a prop pitch that gets you to that hull planing speed at around 2500-3500rpm. ... which on a 2:1 leg, means prop is spinning 1250-1750 rpm. So what pitch prop will give you the speed you need at that rpm (15p, 16p, 17p etc) If you have a really heavy hull, with a bow shape designed to generate lift (not slice through water), then you may need to drip in pitch to generate more thrust in the early 2500-3500rpm range. The motor may not have enough torque to spin a bigger diameter/higher pitch prop with that weight early on. Etc etc The next band is Cruise (hold torque) 3500-5000rpm. Final band is WOT 6000rpm ... max speed... motor needs to be able to spin that prop with your hull weight and hit 6000rpm. If it can do that then its not working "hard" ... its working within its design. As @wrxhoon1said earlier on, selecting the optimum prop is trial an error. Make sure you negotiate in the price the ability to trial several props. The dealer will have a lot of data as well and will probably recommend a "safe" pitch. You have trialed the boat with a Mirage 14 x 15p so have some additional insight to start from. My prop is an Enertia 14.5 x 17p... so bigger diameter and more pitch, thinner blades (less drag). Cheers Zoran

RMS has the following to say -- each person is rated at 90kg which includes personal gear. So if you need clarification best advice is to go back to the dealer/manufacturer and get it in writing if the payload includes the motor etc.. As skipper, RMS will hold you responsible to reduce the load if you are going into open waters... as skipper you are responsible to judge the sea conditions of the day. https://www.rms.nsw.gov.au/documents/maritime/licence/boating-handbook.pdf page 33. Cheers Zoran

The Merc price seems high ... I have always found my dealer to be very competitive. SMS or PM me if you want the details. Cheers Zoran

I've tried to answer that before. @wrxhoon1 tried to explain as well. How do you want to measure "less hard" ? Fewer engine RPM to deliver the boat same speed? Is that less hard? Fewer moving parts for that given speed? Is that less hard? Lower fuel consumption for a given speed? Is that less hard? Cheers Zoran

That has been my criteria and also my experience repowering my boat. I moved from a V6 2.5L 200HP 2stroke (so more power per RPM than a 4stroke), and the bigger displacement 4cyl 4st has identical holeshot, better midrange holding power and almost identical speed performance in midrange... ...from 55km/h above the V6 had the lead and the V4 maxes at 73km/h where as the V6 took me closer to 90km/h. @Cladone, from what you have described, your boat is heavier than mine. I run a typical fishing trip with 2-3 onboard and 2.1T... if we are just boating, like this past weekend I may have 5 aboard (but the fishing gear does not come along) so I am still around the 2.1T mark. We cruised 136km ermington to pittwater and return, chewed 96.7L of fuel, with speeds up to 67km/h. I'm running a 17p prop. As I understand it, your hull is 400kg heavier, so with your typical load you will be over 2T and may go to 2.5T. If you prop down to a 15p, then you'll be revving 12% more to keep the same speeds and roughly using 12% more fuel,... or running at lower RPM/speed to keep the same fuel consumption... IF you can keep the boat on the plane at those speeds. Because you are looking to cater for that 2.5T load ... and it sounds like you want the hull to perform then as well - it may be best you focus on the 175hp and above. Cheers Zoran

2.5:1 means 2.5 engine RPM to 1 prop RPM. This is a 6cyl so 467cc per cyl, for each engine RPM 3cyls fire-spark (or as @wrxhoon1 says have to be fed) ... so 2.5 X 3 = 7.5 x 467cc = 3.5L of fuel/air volumetric consumption per prop RPM. You will get the torque but you will be feeding the fuel. The Merc V6 175hp 3.4L from memory has 1.8:1 ratio ... so less then 2 engine RPM to one prop RPM. The Merc V4 150 has a 2:1 ratio ... etc. It's the prop diameter, RPM and pitch that give you the thrust. The motor has to have the torque to spin that prop across the rev range. Prop pitch determines speed. Have a play with this calculator and plug in different engine RPM, gear ratios and prop pitch (initially just assume slip is 0 or 10% and keep it constant for all cases). http://www.csgnetwork.com/marinepropcalc.html This will help you get a feel for what the motor needs to do (RPM), with different lower leg gear ratios to keep the boat speed the same. Or if you keep motor RPM constant, what different low leg ratios will give you in terms of speed using the same prop pitch. Cheers Zoran

Actually I was referring to the Merc 3L 4cyl and Merc 3.4L 6cyl... I didn't have the specs on the Honda. What I noted was: 4cyl 3.0L capacity = 750cc per cyl. 6cyl 3.4L capacity = 567cc per cyl Four-stroke & 4 cylinders engine => 0.5 * 4 = 2 sparks per revolution Four-stroke & 6 cylinders engine => 0.5 * 6 = 3 sparks per revolution. So per RPM, this is the volumetric capacity injected into the cyls: 4cyl 2 x 750cc = 1500cc 6cly 3 x 567cc = 1701cc So yeah... per RPM the 6cyl uses more. Cheers Zoran

Sorry .. Maria called pen's down for dinner ... so to finish the thought process above ... I'd want to see a commitment that the v6 Merc can spin an 18p prop and deliver the above performance before I'd concede equivalence on fuel consumption and hard work... (that should equate to about 10% drop in engine RPM for same boat speeds. Thats just my view... other more engine knowledgable folks can chime in with their experience. Cheers Zoran