won't go over 3200 RPM

T

ted seres

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Joined
Aug 6, 2007
Messages
3
I have a 1995 OMC 5.8. On my last trip the engine would not go over 3200 RPM> Checked for weeds then started the engine again and it worked fine... for a few days then the same thing happened and continued. Changed the plugs and feul filter. Engine starts and runs great at low RPM but won't go over 3200 RPM. Is it electrical or a fuel problem?
 
wire2

wire2

Lieutenant Commander
Joined
Jun 25, 2007
Messages
1,584
Re: won't go over 3200 RPM

A bit more info is needed.

Does it accelerate from 0 normal, or slower? Any difference moving the throttle from half to full? Will it go over 3200 in neutral? Any odd sounds or smell? Smoke? Engine misfiring?
 
Don S

Don S

Honorary Moderator Emeritus
Joined
Aug 31, 2004
Messages
62,321
Re: won't go over 3200 RPM

Here is a list of possible causes of low WOT (Wide Open Throttle) rpm.

Engine Won't Reach Operating RPM. Check

  • Fuel condition. Type and Octane possibly old fuel
  • Propeller pitch or diameter, damaged blades
  • Restricted fuel pickup tube or anti siphon valve Fuel System Test
  • Crankcase oil volume, high oil level can cause aerated oil and lifter collapse
  • Marine growth on hull and outdrive
  • Wrong gear ratio in outdrive
  • Restricted carburetor air intake (clogged flame arrestor)
  • Restricted exhaust system (broken exhaust shutters/flappers) in engine transom shield or drive
  • Poor cylinder compression Compression Test
  • Carburetor defective, or wrong type.
  • Fuel pump pressure and vacuum
  • Boat overloaded, improperly loaded, or improperly trimmed.
  • Engine Overheating
  • Engine timing and ignition system operation (Full tuneup done recently)
  • Remote control cables and linkage for proper travel to open throttle plates fully.
 
J

jfl1959

Cadet
Joined
Jul 14, 2007
Messages
20
Re: won't go over 3200 RPM

I know it may be a pain in the butt, still you should check Dons list.

When the boat wont get up to the right WOT it could be so many things. I know from experience. I got up to dirty flame arrestor on mine when I had that problem. I never in a million years would have got around to it. But sure enough after cleaning my flame arrestor in carb cleaner the carb got the air it needed and problem solved!

Really, go down the list and you will locate your problem.

Jim

By the way start with the easy checks first (like dirty flame arrestor, duh)

Good luck
 
T

ted seres

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Joined
Aug 6, 2007
Messages
3
Re: won't go over 3200 RPM

It seems to accellerate normal. I've checked the throttle cable and it seems OK. I'm wondering about the feul pump.
 
T

ted seres

Recruit
Joined
Aug 6, 2007
Messages
3
Re: won't go over 3200 RPM

It will go over 3200 RPM in neutral. Everything seems normal until after 3200. Then it just doesn't go any faster.
 
180shabah

180shabah

Rear Admiral
Joined
Mar 26, 2005
Messages
4,995
Re: won't go over 3200 RPM

ted seres said:
It will go over 3200 RPM in neutral.
Click to expand...

That doesn't mean anything, and is not good for your engine.

You need to start eliminating items from DonS's list, which comes straight from the Merc manual.
 
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