Wow feral, 10% worse is very strange, especially considering the generation(s) gap in the donks! What cat and how much heavier are the XB’s? Props definitely sound wrong, maybe motor height too maybe - as that’s a very unexpected performance penalty.
Yeah, stoked with mine. Time will tell I guess, the real figures will be revealed when I can get her ‘fishing ready’ and do a big loaded trip etc.
cheers
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660 noosacat, simular size and weight of the 2300 series that flex has.Originally Posted by gofishin
I have added about another 100kg on the bum with the xb's. Fuel econemy was worse from the get go with spinning A few different props.
Built bigger pods to suit and still no difference to econemy. I took the 14 1/4x17 four blades for a run it feels weird as buggery. Huge arse lift (which is there claim to fame) and felt like i had run out of trim to lift the bow. Hit 40knts at 6000rpm
Ill keep them for a loaded trip and see how they go on eceonemy. The 3 blades would drag its fat arse in swell and burn excess fuel. In calm conditions i would get good eco but unfortunately off fraser island its rarely flat. Lol
What about motor height feral? Two different brands can both be the the nominal ‘XL’ etc, but can regularly require different bolt hole mounting due to differences in actual motor dimensions and number of mounting holes etc.
Have you tried raising the donks? With plates parallel to the hull plank, how much higher are the plates? And how long are the pods?
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Sorry flex, i dont mean to hijack your thread.
Gofishin i have had them up as high as they can go with cav plate 95mm above bottom of hull. Old pods were 400 mm long and we have taken them to 600 long and another 170mm wider. So engines are 200mm further back. Funnily enough fuel economy hasn't changed but i'm not sure i'm sold on the looks as i'm most likely going to pull back off and chop 90mm off the length but that's another story.lol
I have tryed 3 blades 18's on 2 different holes and the 17's on 2 to different holes and now the 4 blades on 1 hole down from the top (cav plate 75mm above hull). Just waiting on reasonable weather and time off to take her on a loaded trip but the 4 blades feel weird. Next step is back to 3 blades with a set of perms.
All good feral, hijack awayI honestly think the design of the 150 yam isn’t for economy. Compared to the suzuki,Honda’s etc they don’t seem to have the tech for economy. Very basic engine , super reliable but low tech.
The 200 yam gets slightly better economy than the 150 due to VVT.
Those suzuki figures posted are excellent figures. I’d be stoked over those.
Also feral the distances you do offshore accentuate any economy issues.
A lot of blokes only do short trips so the economy can seem better than what it is.
I was going to test my 20p’s this weekend but cyclone is ruining my holiday!
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Yeah sorry flex, but I guess it is still on topic [emoji16].
Feral you have certainly tried a lot of height options, but that’s good, only way to tweak the best out of her! If you weren’t suffering any ventilation or performance issues I personally would keep them high, especially if you are adding permatrims.
As for the bigger & longer pods improving economy - I would expect only possibly if they were full hull extensions. 600mm setback is indeed a long way back, so 75+ above the plank doesn’t sound too high.
Re weird performance you mentioned up high, you could also try swapping the g/boxes over so rotation is arse-about. NC are installing like this standard now as it improves the performance They experimented with the selective rotation Zukes and found it was better, so I believe they are doing this across the board/all motors (per Wayne’s comment to me early in the year). Some yank cat manufacturers have been doing the same for a while I believe too.
Cheers
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F150s have a following here on the Sunny Coast over the Suzukis. One mackerel pro I know changed from Zuke to Yam and has never looked back. They love the CCs being a 2.6 litre motor. I also remember Skipalong from here also thinking of going Zuke to Yam on his PPP for load carrying due to the gear box ratio of the Zuke. He was crabbing with it and a mackerel pro here had the same setup as him but with a Yammie and was doing way better figures. I know the guy I bought my Stabicraft off of had another one or two built after it and as he went though Leisure Marine when they were still around he had Hondas on the last few. I usually run into him at the boat show every year and some years he has them on display. I noticed he ran Permatrims on the ones with the 135 Hondas but he didn't need anything on my 140 Johnuki. The 135 Honda is the same CCs and weight as the 150 Honda isn't it. Not many Hondas here on the north coast. Few F150s on a couple of NC2700s here too, one spanner crabber and one deep drop fisherman.
Hey Feral,
I'm going thru exactly the same as you but on the NC3100 with twin 250 yammis.
I made up pod adaptor plates and bolted them under the pods to bring them back to where they were originally after being raised and found that the boat was very stable but fuel economy went south.
Obviously because I then created more drag under the boat.
I have now removed them plus the spray deflectors and the perma trims, tried 15", 17" & 18" props, raised the motors one hole, put the spray deflectors and perma trims back on.
The boat walks a bit but I actually prefer it that way. It seems to ride much better
I have now managed to get it back to something a bit more manageable but like yourself I'm also after range fully loaded and need the boat to do 30knots as that's the best performance ride for the boat.
I have data for 10 different set ups now and want to do a trial with a set of 19's but they might bog the boat down in heavy seas and be much worse economy.
It's hard to compare the data tho, as it's done on different days in different conditions.
Just need to do more trips to see what works best.
Perseverance will get us there
The torque curve on the 4.2 litre Yammies is weird. The shark net contractor here repowered original F250s for new 4.2 litre ones and had to dick around with props heaps even though it was same horsepower for same horsepower and they took a lot of getting used to. 10-15% better economy on that and a spanner crabber here who did the same on a Kevlacat, just they did totally different things at different revs with different speeds they were happy etc.
Smithy, do you know what props they ended up using?
I've tried 15-3/4" 15T, 15-1/2 17T, 15-1/4 18T & a set of 17" Lexor Plus.
My aim is to get 30 to 31knots @ 4200 to 4300 rpm.
This will give me the best fuel economy, distance travelled & optimum ride for the boat.
Currently got it running at 28 - 29knots, which is why I want to give the 19'" a run.
The motors are still in run in stage and I'm told they will get about 2 - 3 % better as they are programmed to run a little richer for the first 100hrs.
Cheers Rob
I would have talked to Keith about it a few years ago. Next time I talk to the NC3100 guys I'll ask for you.
That is Keith's old boat, he's now moved on to a 41 footer and he has been involved in the trials.
Cheers Smithy
Yeah mate the extra 200mm setback was a bit of a stuff up but im running with it for now. 2300's are 510mm long and for cosmetic reasons ill pull pods off and chop them again. Another issue i have is excessive spray going on the engines now at around 12 to 15 knts. We made the pods without the spray plate left on the bottom overhanging 100mm.
The economy is no better or worse now comparing to old pods, the extra 100kg on the arse must be enough to tip it over the edge in swell to get such bad economy. In swell it feels boggy and i can see the ltr/hr go through the roof. Thats why i think perms or 4 blades should help maintain lift at 25knts in swell and give better range. Funnily enough though with the 4 blades on the other day just mucking around in the wide bay bar i was smashing along at 30knts in slop for the softest ride I've ever felt in it. Felt like i needed a tad more bow up attitude but just couldnt quite get it there but i could plane at really slow speeds. Thats why im keen to do a loaded trip and see what the eco is like and ride etc before i put perms on and back to 3 blades for a trial. Ah flippen boats doing my head in. 😂
Yeah mate its frustrating to say the least, I bought these engines because I wanted more grunt than the 115's but I also didn't want a beefed up 115 into a 140. I thought these would be better on fuel than my 02 mods as I want to start doing a few trips to the swains from 1770, hence higher cruise speed when I can and the f150's do it easy being a bigger cube engine. To bolt these up and have worse eco is disappointing. I'm going to gut the front of my boat as well next trip and lay anchors etc at the back with these 4 blades. I'm running powertech props and have been swapping them out since may this yr. Just recently they handed me about 5k worth of gear and sent me off to test. Can't complain about there service.Hey Feral,
I'm going thru exactly the same as you but on the NC3100 with twin 250 yammis.
I made up pod adaptor plates and bolted them under the pods to bring them back to where they were originally after being raised and found that the boat was very stable but fuel economy went south.
Obviously because I then created more drag under the boat.
I have now removed them plus the spray deflectors and the perma trims, tried 15", 17" & 18" props, raised the motors one hole, put the spray deflectors and perma trims back on.
The boat walks a bit but I actually prefer it that way. It seems to ride much better
I have now managed to get it back to something a bit more manageable but like yourself I'm also after range fully loaded and need the boat to do 30knots as that's the best performance ride for the boat.
I have data for 10 different set ups now and want to do a trial with a set of 19's but they might bog the boat down in heavy seas and be much worse economy.
It's hard to compare the data tho, as it's done on different days in different conditions.
Just need to do more trips to see what works best.
Perseverance will get us there
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