1988 sea ray 100 hp bogging on take off

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Bubbat450

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Aug 8, 2011
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Hello I have an 88 sea ray 100 hp bogging on take off, I bought it from a friend that barely used it.
i took It out a couple of weeks ago for the first time and it ran great. It hadn't been ran in a while. I
took it out last Saturday and it Boggs really bad till it plains out and it take twice as long to plain out
then when it was running good.

I've read about the 2+2 motors and was wondering how to tell the difference.
No mods have been done to it
It idles at 2000 rpm if the tach is right

Help!!!!
 
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Bubbat450

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Re: 1988 sea ray 100 hp bogging on take off

Update:
Put new plugs in and it ran great for about an hour or so.. After running wide open for about 15 min I came to a stop then i took off again and one was fouled again.
 
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CharlieB

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5,617
Re: 1988 sea ray 100 hp bogging on take off

Trim the motor level, remove the airbox cover. Pump the primer bulb while looking down the carb throats, any fuel ? It's flooding that cyl. Oder carb kits and do ALL carbs.

Check to see which cyl the fuel pump vacuum hose is, if that is the cyl with the fouled plug disconnect that vacuum hose and see if it is wet inside from a pin-holled diaphragm flooding only that cyl. If so, order a fuel pump rebuild kit.
 
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dlplost

Petty Officer 2nd Class
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Jun 6, 2008
Messages
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Re: 1988 sea ray 100 hp bogging on take off

Yer Tach is wrong, Idling at 2,000 rpm would destroy the lower unit when you shift into gear.
The "2+2" drops 2 cylinders below about 1800 rpm and just runs on the other 2.
It will not tolerate the cheap Wallyworld...etc injection oil, it will foul the 2 that aren't running.
Next time you pull a fouled plug, look for tiny black flakes on it, thats ash from the oil.
It needs the expensive Quicksilver, or Johnson/Evenrude oil.
I allways thought if it meets the spec it's the same oil, not true. I wasted an entire summer dealing with this issue back in 1988 with a brand new 16' Searay.
 
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Bubbat450

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Re: 1988 sea ray 100 hp bogging on take off

Thanks so much for the help.
I'll check the primer bulb. I can do that with the motor off right?

It had quick silver premium in it and I put the quick silver premium plus in it. I just drained it out and going to get the premium (red lable).

Last night it was idling at 800 rpm when the plugs where new, a little higher after foul an
defiantly Rougher but not 2000 rpm
 
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Bubbat450

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Re: 1988 sea ray 100 hp bogging on take off

Another note:
Fouling doesn't look that bad to me, it's the flat plug style.. It's turning the white insulator
part black.

I race off road motorcycles and have alot of time on two stroke but this is new to me!
 
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Bubbat450

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Re: 1988 sea ray 100 hp bogging on take off

Update:
I took off air box cover, looked down each carb and didn't see any fuel coming out as I
pumped the primer bulb. when I took off the cover there was a lot of oil on the cover and bottom carb.

Took off the vacuum hose, it's oily but no gas.

I'll get some new plugs and take it out, I'll replace each plug till I find which cylinder it is.
 
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Bubbat450

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Re: 1988 sea ray 100 hp bogging on take off

I may have found something, if the motor is tilted up for a few days gas is getting into the air box and evaporating and leaving oil there. When I lower it and start the motor all that oil runs into the carb! But when I pump the primer no gas comes out of the carbs!
 
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CharlieB

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Re: 1988 sea ray 100 hp bogging on take off

The 4 cyl in-line 2 + 2 system does not have adjustable idle mixture screws on the bottom two carbs, instead, they have an accelerator pump, the plunger is cam operated bby the throttle arm.

The injector pump feeds two injectors, one each for the lower two cyls and are located under the ignition/electric plate on the port side. A failing accel pump and/or dirty injectors will cause poor acceleration, yet once up to speed the motor will top out fine.

ALL carbs leak fuel at full tilt on the trailer. The airbox has a recirc hose on the bottom that feeds back into the recirc system to use the oil, eventually.

Recirc hoses age, crack, suck air into the motor, the fittings can clog, a syringe of alcohol is a handy way of clearing/cleaning hoses and fittings. One fitting on each hose has a one-way check valve, and may need to be removed for cleaning.

Carb float height should be checked and adjusted is necessary, too high a fuel level in a carb will cause an overly rich mixture and lead to shortened spark plug life.

Idle mixture on the carbs with adjustable idle mixture screws should be set while running IN Forward gear and IN the water. Set to best idle speed PLUS almost an eigth turn out (CCW) to provide the additional fuel for crisp acceleration. Test holeshot, even the slightest hesitation, add idle fuel just a scooosh and retest. Repeat to perfection. Additional load, full coolers, a skier, etc., may require slightly more idle mixture.

NOTE: Accel pump and injectors MUST BE PERFECT to bring in the lower cyls for acceleration.

The 2 + 2 system works so well, once dialed in, many owners don't even notice the difference.
 
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Bubbat450

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Re: 1988 sea ray 100 hp bogging on take off

That is great info! Thank you so much. I took it out last weekend and it was bogging, so I
Changed the spark plugs one at a time while I tested it. I thought I would find the bad
cylinder but it just got a little better as I replaced them.. It work great till I let it idle while
coming up to the dock and trailer. I will try the stuff you said.. Thanks
 
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