rozza_b Posted September 13, 2016 Share Posted September 13, 2016 Hi guys, So im after a bit of advice on prop selection for my boat, i have a 4.88m centre console Quintrex with a BFP60 honda on it, currently i seem to be getting a lot of prop slip while trying to take off, as in the engine revs up but just doesn't seem to be able to push me along, eventually it will get going and pushes me along fine but if im in a bit of slop it sometimes struggles to hold the speed im at. So i have done some research on the honda site but due to my engine being a powerthrust model it doesnt offer me any advice on what prop i should fit. I did go back and check the non power thrust model and it provides some options but im wondering if they would actually be suitable and if not would best be suited to my boat. The current prop fitted is a 3 prong M 13-1/4 x 7, any advice on what my options are would be greatly appreciated, im mainly after something just for general fishing use, thanks in advance Rozza Link to comment Share on other sites More sharing options...
squidboy Posted September 13, 2016 Share Posted September 13, 2016 Prop size seems ok, maybe drop the motor on hole spot. You should get better holeshot but a lower top speed by about a knot or two. Link to comment Share on other sites More sharing options...
The Incredible Hull Posted September 13, 2016 Share Posted September 13, 2016 When you're at WOT (max speed), what are the revs like? Is it over reving or under? Link to comment Share on other sites More sharing options...
rozza_b Posted September 13, 2016 Author Share Posted September 13, 2016 Dropping the motor shouldnt be needed as its a long leg motor so its down pretty low in the water currently, maybe that is having some effect on it ? I have been advised to get it raised up a few inches and intending on doing so once i can actually get it done. As for the revs flat out it is only doing around 4k, which is under revving i believe, i think i need to adjust the throttle cable though as i removed the engine cover last week and found that when the throttle lever is pushed all the way forward their is still movement available on the throttle arm on the engine. Even then though when i take off in the boat at full throttle is goes to somewhere around 3k but doesnt really accelerate quickly, just revs and slowly pics up speed. Link to comment Share on other sites More sharing options...
Ric001 Posted September 13, 2016 Share Posted September 13, 2016 Before adjusting the throttle review whether it is correct. The bfp motors were designed for heavier loads such as house boats and pontoons not high revving for runabouts. I have a bf60 that revs out to 6 under load and can pull 3 adults on a tube. It may be the wrong engine for you boat. Sent from my iPhone using Tapatalk Link to comment Share on other sites More sharing options...
Ric001 Posted September 13, 2016 Share Posted September 13, 2016 The gearing in the leg may also be different. Sent from my iPhone using Tapatalk Link to comment Share on other sites More sharing options...
Foghorn Posted September 13, 2016 Share Posted September 13, 2016 I was not happy with my boat and contacted solas they recommended a new stainless prop but well worth it, higher speed less revs less fuel. Hope this helps. Link to comment Share on other sites More sharing options...
rozza_b Posted September 13, 2016 Author Share Posted September 13, 2016 Yep am aware that this motor is designed for this, but the throttle not reving the whole way is the same no matter what motor it is, it will still rev its entire range but as you have said the gearing may be different. The problem isnt so much the reving its is the fact that it revs but doesn't accelerate the boat, if the water is nice and flat it gets going ok, but once you had a bit of chop or a bit of extra weight, it revs but doesnt accelerate very well. Thanks foghorn i might give them a ring and see what they have to say. Link to comment Share on other sites More sharing options...
JonD Posted September 13, 2016 Share Posted September 13, 2016 Not trying to knock anyone's advice but if you give Solas props a call with all the info on max rpm and the current prop etc they will normally put you smack onto the right prop you need without all the guess work. They have helped me squeeze the best performance out of every boat I've owned over the last 15 years. Jon Link to comment Share on other sites More sharing options...
Croydon Posted September 13, 2016 Share Posted September 13, 2016 (edited) Plus one for solas, been using them for years. Great service and advice every time. Worth a call. Should be seeing 5000 - 6000rpm at wot when propped right. Good luck with it. Cheers........ Dave Edited September 13, 2016 by Croydon Link to comment Share on other sites More sharing options...
The Incredible Hull Posted September 13, 2016 Share Posted September 13, 2016 Dropping the motor shouldnt be needed as its a long leg motor so its down pretty low in the water currently, maybe that is having some effect on it ? I have been advised to get it raised up a few inches and intending on doing so once i can actually get it done. As for the revs flat out it is only doing around 4k, which is under revving i believe, i think i need to adjust the throttle cable though as i removed the engine cover last week and found that when the throttle lever is pushed all the way forward their is still movement available on the throttle arm on the engine. Even then though when i take off in the boat at full throttle is goes to somewhere around 3k but doesnt really accelerate quickly, just revs and slowly pics up speed. If its under reving then you'll need a bigger prop with bigger pitch. Obviously you'll only know this at max speed. Keep in mind, if you get a prop that gives you 5500-6000 at max speed, you'll get good speed at top end and poor take off. Any lower than obviously you'll get better take off but over reving at top end. I take it you want something right in the middle. Also you'll want a stainless prop as they don't warp. As suggested above, contact a professional for advice on what prop size you'll need. Give them your current prop specs with revs at WOT. Link to comment Share on other sites More sharing options...
rozza_b Posted September 13, 2016 Author Share Posted September 13, 2016 Thanks for all the replies peeps will definitely be getting in contact with a professional and see what they have to say. Cheers Link to comment Share on other sites More sharing options...
rickmarlin62 Posted September 13, 2016 Share Posted September 13, 2016 you list prop as 13 1/4x7 but im unsure bout this as I have 60hp yammie with 13 1/4 x 17 pitch u may need to look at the pitch Link to comment Share on other sites More sharing options...
hookmeup Posted September 13, 2016 Share Posted September 13, 2016 I agree pitch of 7 inches is not correct, however I have noticed with tilt/ trim if it's not correct prop cavitates until you get up to speed & On the plane & then you get max speed, or when wot trim is up but down low speed you do get cavitation, so you have to constantly change your trim ( does all that make sense ) Link to comment Share on other sites More sharing options...
JonD Posted September 13, 2016 Share Posted September 13, 2016 I figured the 7 inch pitch must of been a typo and he meant 17, if so with those rpm readings he would be needing to drop down to at least a 13 pitch. On my yam f70 I get the same rpm from an alloy 15 as I do with a Solas stainless 13 pitch, the Solas gives much better all round performance though. I'm also wondering if maybe the prop is slipping on the internal bushing, if so Solas can also repair most bushing. Jon Link to comment Share on other sites More sharing options...
spanish Posted September 17, 2016 Share Posted September 17, 2016 I would ensure your outboard is mounted at the correct height before wasting time and money on fitting different props. Link to comment Share on other sites More sharing options...
JonD Posted September 17, 2016 Share Posted September 17, 2016 Engine height can vary depending on the users need, take a look here to get an idea http://www.boats.com/how-to/the-outboard-expert-boost-speed-with-outboard-engine-height-adjustments/ Most manufacturers tend to fit engines a little lower than needed which helps with inexperienced new boat owners in regards to cavationtion and trim. You can normally raise an outboard 1 or 2 holes but will need to work the trim control more. The antiventalation plate sits very high out of the water on race boats causing less drag and higher performance etc. I've moved every outboard up on every boat I've owned. Jon Link to comment Share on other sites More sharing options...
BWV Posted September 20, 2016 Share Posted September 20, 2016 Your under reving, if your rev range is 5000/5500-6000rpm you want it reving at 5800rpm under normal load at full power, at 5800rpm you'll have the best balance between engine load, speed and efficiency. You should always aim for 200rpm less than the stated maximum figure that under normal load so when light you won't exceed the maximum revs for your engine. On the flip side overloading your engine, as in not be able to achieve the given rev range will do just as much damage to the engine. For engine height, you want you antiventilation plate getting splashed by the spay not dragging though the water, every boat I have ever seen that is new has the engine mounted far too low. Link to comment Share on other sites More sharing options...
dunc333 Posted September 20, 2016 Share Posted September 20, 2016 i would first check for prop slipping to.some props have a rubber bush that slips when you hit a log or debris.easy to replace .once the rubber hub is coprimised it needs to be replaced .and they usually slip when hp to the prop is needed like you are describing.+1 for solas as well if you arnt happy with prop sent they will let you send it back and try another .cheers hope this helps regards dunc333 Link to comment Share on other sites More sharing options...
tackleberry Posted September 20, 2016 Share Posted September 20, 2016 if he's only getting 4000rpm he hasn't got prop slip on the bush Link to comment Share on other sites More sharing options...
rozza_b Posted September 21, 2016 Author Share Posted September 21, 2016 Thanks for the info all, definitely have a few things i need to look at now and will get into them over the coming weeks, will let everyone know how i go once I've gone through everything. Link to comment Share on other sites More sharing options...
dunc333 Posted September 23, 2016 Share Posted September 23, 2016 (edited) maybe tackleberry .boat rule 101 dont buy a new part till you have examined the old part (eg prop) and found why its failing if hub good go to new prop. to me the prop size is close to boat description cheers dunc333....my money is on the hub !!!!!!!!!!!!!!!!!!!! Edited September 23, 2016 by dunc333 Link to comment Share on other sites More sharing options...
dunc333 Posted September 23, 2016 Share Posted September 23, 2016 tackleberry moneys on the hub rule 101 dont buy a new boat part till you have checked out the problem cheers dunc333 Link to comment Share on other sites More sharing options...
Twinfisher 4.9 Posted September 27, 2016 Share Posted September 27, 2016 I agree with JohD, Solas are great and am sure they will help you out. Steve Link to comment Share on other sites More sharing options...
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