Motor Help!!??

[justfishin]

I've been having this problem with my motor for quite some time now.
I'll start it and let it warm up while sitting in the boat slip, some times it starts easy, sometimes a pain in the rear!

Can sit there with it in N, rev it up and it runs fine, back out,head past no wake area and throttle down and it just bogs down, no power, no RPM's. Can immediately put it in N and revs right back up, put in gear bogs right back down!@#$%

Can go along with it boging and it will start to sputter and come to life, most of the time, or it just dies and its a pain to get going again.

I have changed the plugs, its getting good fire to all 6, rebuilt the carbs, new coils, drained and cleaned entire fuel system,no air leaks, last week had a buddy in the back squeezing primer bulb to make sure it was getting fuel with no effect, finally cleared up and ran like a bat???

Had a guy today say it may be reeds, but he was no boat mechanic. Getting ready to shoot a hole in it and sink it, want to fish not work on boat!

It's a 1990, 150 HP Evenrude 6 cyl

Thanks for any help at all , Jim

[dipsydiver]

Have you checked the fuel pump?

[Shellback]

Ignition timing can have that effect on a motor. I think at least some outboards have linkage that changes the timing with the advance of the throttle.

[justfishin]

Have you checked the fuel pump?

I'm suspicious of the fuel pump.

[Scrapper]

typically, if you pump the bulb and it doesn't help its not the fuel pump. I would check and make sure the timing is advancing as it should. Have someone work the throttle with the engine not running and watch the linkages...there will be one linkage that goes to something under the flywheel...that is where the stator and timer base are...the timer base should move as you increase throttle...there are rollers and linkages that should be free moving under there...make sure its all moving. If you do this to no avail...and you have a nice BLUE spark...that needs to be able to jump about a 3/8" gap (tester)...and you are getting fuel...I think its time for a compression and leakdown test. A low compression engine will do what you are describing...probably what your friend was thinking when he said reeds...but you'll normally get a back fire or such when reeds aren't sealing. Just some stuff to check. Let us know how it goes.

[justfishin]

The confusing part is that it will clear up and run like new! Last weekend I ran as much fuel out of it as I could, wife and I rode around in big cicles for 2 hours without as much as a miss ????

[Scrapper]

Did it just start this?? You may have an air leak somewhere...when you finally get warm it seals off. Maybe an intake leak or something. These are the things that will drive a guy crazy trying to track down. Even a linkage can freeze up until everything gets warm under the cowling. Try to move everthing under there...make sure its all free.

Did it just start this?? If its just getting on plane that is the problem....lugging and bogging down...have you hit something with the prop?? If its always done this I would look at vent holes or a lower pitch prop. Just trying to get it all out there.

What about the lower unit?? Oil look good?? A seizing lower unit can run good when warmed up but bind when cold...for a time until it goes out.

Go have your electronics ALL tested. Less than a 100 bucks at most places. If you have a timing base or stator going bad things like this can happen. If you do not advance timing she will not want to go with much resistance on her. Have them check the powerpacks, stator, timing base, coils, rectifier...all that stuff.

You are getting fuel or it wouldn't run out like you are saying.

[The Marine Doctor]

My 2 cents... power pack is not working properly.

You have the optical eye ignition system on there and I have seen the power pack do some flaky stuff.

I bet if you check the spark when its hard starting...there is none.

Take and tap the pack while the engine is running and see if you get a response or change in the way the engine is running.

TMD

[Scrapper]

Marine Doc...when did they change to the optical?? I thought a 90 model was probably still a GT or standard engine?? I know the early 90's fast strike and intruders were HOT!! LOL When did they put the optical ignition in?? Thanks.

[hudnut]

I had the same problem on my 125hp. It turned out to be a timing issue. Have someone pull the flywheel and check the timing.