motor won't plane out with a load

[LMBarnett]

I have an 04 2-stroke Tohatsu (Nissan) motor. I noticed a problem at the beginiing of duck season. When I am in the boat by myself it seems a little sluggish on take off, and gets more sluggish the more weight that is in the boat, up to the point where it won't plane out with 3 guys (with waders shotguns, and decoys) in the boat. It ran fine with 4 guys last year. I have changed gas (with new seafoam), and changed the plugs, and it still happens.

Any suggestions would be helpfull.

Matt

[olesilverside]

You either have a power pack problem, or is your engine reving up on take offs, if it is you are starting to spin out hub on propeller..... Or worse you have ring or piston problem, mine unfortuntaley was rings.......

[Barnacle Bill]

You could be dropping a cylinder or have a fuel blockage. Check for a strong spark on all cylinders. When is the last time you changed your fuel filter?

[Iamfishing]

Same thing happened to me a couple years back. Boat left the dock and ran great out to eight miles. Fished all day at idle and on trolling motor. Headed back in and wouldn't plane out. Finally got back to the dock. As my buddy got the truck and trailer, I shifted the motor out of gear and reved the motor up to 3500/4000 rpms couple of times. Then headed out and wop the engine. It sputtered a couple times then caught and ran great. Trash in the carbs.

[Windjinx]

I recently had a similar issue. I have an 2004 Nissan 4-stroke. Motor seemed to run as if being choked with to much fuel. Did not want to idle very well. Some times it may even surge a little. Took it to the local Nissan repair shop. He told me that these motors have extremely small jets that get blocked easily. However, I am extremely regimented about using new fuel and not keeping old fuel. These motors are shipped with a resister plug in them when they are new. He replaced it with a non resister type. Well he cleaned the jets, adjusted the valves and carburetor. If you have not had the valves adjusted you should he explained that these motors should have them done after about the first 25 hours of use. Anyway he told me when I got it back it would run better than it did when it was brand new. Well when I received it back it was true to his word. It definitely did.

[quad700]

Make sure its circulating water and not getting hot.

[osagemo]

I had some issues with my Yamaha jet a few months ago. They cleaned them and put a new fuel pump on which solved the problem, although it was $360. I think he's a pretty good mechanic and he told me that he had never seen so many carb problem before..

[Scrapper]

all the above posts are right...could be any of those things...first off, just like was already asked. Is it reving when you are trying to get on plane?? If an outboard doesn't reach 3500 rpm on take off it will have a hard time planing out. If it is reving and still not getting up...look at prop...ie...spun hub...check this by taking a marker or something you can see...and make a mark across the hub onto the prop itself...make a few runs...on and off the throttle. Stop and check your mark...if your mark is still straight you are good...if its off..you are probably spinning a hub. Do this a few times just to make sure.

If thats not it...do a spark test..go to parts house and get a cheap spark tester...put it on and look for a spark...should be bright and blue..not yellow or orange...nice and blueish white like lightning...should be able to jump 3/8" gap.

If that checks out, make sure you are getting fuel...not breaking into the carbs yet...but checking lines...the bulb...a bulb that will not hold prime can do this...people will throw all kinds of money at it....and replace the bulb and fixes it...it has to be able to hold a prime.

If it still does it...have a compression check...

I'm doing this by cheapest and easiest first....

If that checks out...then have carbs rebuilt...or you do it yourself.

Has to be one of three things....air/fuel/spark.

I would check out the lower unit too...make sure when in netral it sounds okay...make sure when you put it in gear and you grab the prop and try to turn it, it doesn't slip...may slip one way...but not the other.

Be sure you haven't hit something with the prop...if you have that could be culprit. Just some thoughts to check out first.

Let us know how its going

[tritonman]

Just got my boat back from the shop doing the same thing however it is a 225 Evinrude. After trying all the above, by accident we saw a leak around a bolt at one of the injectors. The bolt had broke and was allowing air in, fixed bolt, running like scalded dog again.

[Scrapper]

triton...DANG! been there done that!! You do everything you can think of and spend money...then you finally find whats wrong and its something silly and cheap! Although it does make you feel good to find it and fix it...and then knowing it wasn't somthing that could've been way worse.