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Help! Low power under load?

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94MercMariner200

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I have 94 mercury mariner 200. I've cleaned out the carbs made sure there's spark(2 new celinoids) and took compression test. Between 110 n 120 psi on all 6. Fresh gas from spare tank running to it. When I put it in the water and give it full throttle it only gives me about 3500 rpms and won't plane out. I don't know what else to do???? Please if anyone's got any suggestions I'd really appreciate it. Thank you-TJ
ps there is a slight knock in it but with good comp I think it's just normal 2 stroke noise... But I could be wrong.
 
Sorry meant coils not solenoids. The motor has ran on the boat well and planed out fine. The plugs all look good and I tested the spark the old fashioned way by letting them rest on something metal n all six sparked fine. It's a 21 foot mako and the same motor for as long as I've had it. The boat sat for 6 years with a run every couple months and it was used once in that time period but only for a couple hrs. My biggest prob is not getting full rpms at wot. It's a slight knock doesn't sound like a rod but if I remember correctly the motor was always a little noisy with the cover off. I was reading about the fuel primer valve have you ever heard of those going out on a mariner ? And would that be causing this issue?
 
So you are just trying to bring it "back to life" after about a 6 year lay up (as described above)?

If I have that right your carbs are probably in need of a rebuild, not simply a cleaning. Gaskets could have rotted, cracked - ditto the fuel pump, impeller (and other waterpump gaskets/seals).

You cold have main seal issues on the crank.

OR did I get you wrong there? It sat "at some point" for 6 years but has been running fine the last season or two????
 
If the fuel primer was stuck open then it would fed too much fuel into the motor.-------Look at it closely and see how it is hooked up.----Then pinch the discharge hose and see what happens while the motor is running.
 
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It ran in my yard for the last year or so fine. Haven't taken it out in over 3 yrs. the carbs looked good inside gaskets did too. Boat ran great six years ago. But yea I'm trying to bring her back to life. Just can't figure out why it's gettin fuel spark n good compression but low power under load.
 
Be sure to check inside the intake runners for any kind of blockage. I just rebuilt my carbs because I couldn't get the engine to run high rpm's,and when I was ready to re-install them, I noticed something down in the intake runner. turns out, some sound deadening foam had fallen off the engine cover and got sucked into the intake. plugged up one whole side of the top carb intake. Of course, this was discovered after I ran a compression test, checked all electrical, replaced the plugs, wires and of course rebuilt the carbs, and pulled most of my hair out and said a few choice words about that boats mother.:D
 
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