Slow getting on plane

onislandtime

Problem just started. 342 twin 350's, full throttle only gets to 3200rpms and takes double to triple the time to get on plane as before. Once on plane, rpms slowly come up. It's not the load on board. Once on plane I trim as always and its seems the bow is just a tad higher as before. Boat runs the same speed as before set at cruise.

aero3113

Are your trim tabs working correctly?

zaverin1

Bottom dirty

zaverin1

Drive trim set properly? Gages work 

onislandtime

I checked the drives and they are going down. Didn't check trim tabs but I know they work cause I used port side to level boat. Bottom can't be that bad yet I hope, but I'm getting the speed I should at a certain setting of rpms at cruise and fuel burn is the same.

Michael T

What position are your trim ram shims in. The position of these can make quite a difference getting onto plane. As @zaverin1 suggests - check bottom. Also have you changed the interior weight in any way? Are you using your trim tabs to assist?

onislandtime

Everything was okay this year until this weekend. The boat performed as expected. Using trim tabs to assist getting out of the hole in my opinion would be a bandaid to a problem. If anyone with a 342 with 350's could give me their rpm reading when starting off.  

Liberty44140

I have the same boat and engine drive package. Props are 3 blade, 22P. To get on plane I have drives down and I use no tabs, they stay up. I take throttles from 1000 rpm to about 3/4 throttle over the course of 5 seconds...after maybe 10 seconds total she plannes out nicely to just over 4000 rpm, maybe 4200, and I then settle her in at under 4000 to go 28ish mph. 

aero3113

Fuel filters?

Liberty44140

aero3113 said:

Fuel filters?

I was wondering about cap and rotor? I pro actively did mine this year and the old were pretty bad 

onislandtime

@Liberty44140 changed cap and rotors a month ago. Those are the same numbers I get. @aero3113 I was thinking that possibly.  

Dream_Inn

I was thinking fuel as well.  Do you have same fuel from over winter?  or have fueled recently?  (should I fuel somewhere else? )

onislandtime

lol no one else is having fuel problem. They turn fuel over quick. 

reneechris14

I'm the same as you 342 350mag stock 22 props. I go from 6 to 20 in 5 seconds. Settle in at 3800ish and 27mph. I always use the taps they do help.

reneechris14

this was Sunday and the boat was loaded with stuff. 

Wildboating

@reneechris14
Care sharing info on your bike mount for the front?

aero3113

Wildboating said:

@reneechris14
Care sharing info on your bike mount for the front?

Looks like a cut pool noodle and rope!

reneechris14

Yup ripped up noodles and some rope. Came down though the windshield right to the dinghy then to shore. Been riding around this island for 3 days now I'm to old for this
Lol

Wildboating

Well, I hadn’t considered that.  Seems easy enough. 

Liberty44140

reneechris14 said:

this was Sunday and the boat was loaded with stuff. 

My raymarine C70 and my iPad are both mounted in the same spots!

Dirtythirty

I had a similar problem last year. My engines would level off at 2700 rpms and my boat wouldn't plane.  After doing some looking around, It all boiled down to this....
My o-rings had deteriorated on my fuel filler caps, allowing rain water into my tanks.  When I began to plane, the water, which was now under the fuel in the tanks, was getting ingested into the fuel lines as the angle of the boat increased with speed. the engines began to sputter with water injection, and wouldnt push through the 2700 rpm barrier. 
Check for water in your fuel....if you have separators ...clean them out...replace your filler cap o-rings.
Just an idea, as I encountered a similar issue.  

onislandtime

I suspect the culprit is water. No sputter yet. If you look at my earlier post I had a water problem in the starboard engine from winter storage. Changed water separators and problem solved. I think I still have some water left. Only second time I have put gas in. The symptoms are less then before. I did replace the O ring to the port gas cap last year. Should have just replaced both lol.