can't get on plane
atlast
Member Posts: 10 ✭
I have a 2005 fv320 with twin 5.0 and bravo 3. RPM's will go past 40 out of the hole but still wont go on plane. I have the bottom cleaned every two weeks and that doesnt help. Ive tried right after the cleaning with no luck .any suggestions
Comments
Gotta be props... Have access to a prop shop with the demo props? Merc sent out blue props to.shops for demo purposes some time back... Those shops are supposed to allow potential customers to test run them... As expensive as biii props are, I'd search a shop out that has them... They gotta be merc prop dealers...
But.. It's gotta be your props if you're hitting 4krpm on a clean bottom and can't get on plane, even with that heavy boat and weakish engines, you ought to get on plane...
Are your tabs functional?
yes they are . what would make the props go bad ?
Damage, pretty much.. you'd be able to see it.. I swapped a turbo precision prop last weekend which was perfect, 14.25x22p for the guys beat up 14.25x21p mirage +$75... He was astounded at the 'smoothness' of the turbo over the mirage... I told him to stay out of the oyster beds and it would remain that way...
Just a lil bit of blade damage can really reduce efficiency and put a kibosh on performance..
Too much pitch or too little can do it too.
PC BYC, Holland, MI
atlast - Something seems off here. How long have you had this boat? Did you just change the pitch of your props and if so, why? Did this performance loss just happen? If you bought it new didn't you take it for a test cruise? What led to this? need that info to help. MT
ive had the boat for four years and never had a problem till 4 weeks ago and cant figure it out..
Are the props cleans too? Not just the bottom.
PC BYC, Holland, MI
atlast - based on your info, I respectfully suggest it is not incorrectly propped or you would have noticed long ago. Do BOTH engines 'sound" like they are revving high, yet you still aren't getting on plane? What MPH are you showing at 4000RPM?You said your boat bottom was just cleaned. Did you see it before it went into the weater? Do you have a bottom coat on your hull? I assume there has been no hull damage or improper storage to deform the boat's bottom. Are BOTH tachometers reading approximately 4000 EACH? I ask because if one engine was off that could stall you out. Your drives are both trimmed in? Your drive trim works? I can't imagine both sets of props failing or both engine couplers failing - at the same time - so I'm guessing that one engine, one drive, one set of props one ignition, fuel or sensor set that is at fault. Sooo we need to know if both engines are behaving the same. I do not think it would take too much to prevent planing as two 302 cubic inch "small" blocks have to work hard to plane a 320. What RPM are did your tachs used to indicate when you did get comfortably on plane: 3400? 3600? You didn't get bad gas by any chance - even though your engines are efi/mfi they might not be able to compensate for a load of real crappy gas? What temperature are your engoines showing? I'm trying to think of everything. Was there any maintenence performed on the engines, drives, props just before this occured? Don't lose heart there are a lot of real smart men on this forum - we'll get at this. BTW obvious question - neither you or anyone else driving your boat hit anything? MT
lots qof good stuff to check, Im going to change out the fuel filters first . In the past 3400-3600 would easily put her on plane. tachs are close in rpms . If im lucky the speedometer gets to 15 maybe 20 mph. one thing i do need to check is the trim. The only maint. in the last 4 weeks has been bottom cleaning. the bottom irs painted. thanks for all the good suggestions ill keep you updated on any progress
The fuel filters could need replacing but IF your engines are turning 4000 RPM then, according to your past performance stats, your boat should BE on plane at 3400 to 3600 - so at 4000 you should be well on plane. IF the bottom is fine then I'm thinking it's something in between the props to the engine couplers. IF the trim sender wiring for your engines had shorted and they couldn't be fully lowered (tucked-in) that could prevent plane, (I say engines as if only one trim sender was out it could effect getting on plane but you'd notice as the boat would be on an angle). Again, to me , the key in troubleshooting here is that the engines are turning 4000rpm, so the boat SHOULD be on plane according to your past performance stats. IF your tachometers are working and you should also "hear" your engines turning 4000 RPM, then your boat SHOULD be on plane. To me that leaves a hull bottom ptoblem, trim/drive problem, coupler(s) problem (but you should HEAR coupler(s) spinning and maybe even smell them) or a damaged props(s) problem. Pls keep us posted. I'm really intrigued now! Good Luck! MT.....atlast: there are several similar posts on another thread about paint residue in the cool fuel modules you may wanty to read. I don't think this applies to your problem as you are turning 4000rpm and SHOULD be on plane. The other guys are jammed at 2600 +/- rpm. Obviously you are not showing any codes/alarms, but have you considered having a code reader attached to your system? MT
check your trim... I doubt you could rev 4000 rpm without jumping on plane with B3 drives unless the drives are untrimmed....or poorly trimmed...
please check the position of the drives and check the trim indicators...they may not be accurate...making you crazy....
AtLast, also bring the port engine to full throttle and notice speed, and then bring on the power to starboard to full throttle. Feel the pull. Now, stop, and reverse the action. Notice if one engine is pushing the boat harder than the other. If you have one engine that has a fuel issue, tune up issue (distributor/wires/plugs), or outdrive issuse, you will be able to at least tell which engine to look at....hopefully.