Evinrude O/B starts bumping over 2 RPM's

ssmith1954

Recruit
Joined
May 19, 2003
Messages
3
I have a 1996 50 HP OB on a Lowe Pontoon boat. Just put back in water after winter. Changed plugs, nothing else. Took out first time. Crusing on low speed, runs like a top. Try to go a little faster 3 or 4 RPM (my speedometer cable is broken), the engine starts bumping up and down like it is going to fall off and RPM's drop. Cut it off. Restart. Race motor, proceed. You don't get very far before it does it again. Fires right up with new plugs and runs great at 2 RPM. Mechanic could not find anything wrong and it only did it once with him. I took it out yesterday, and it happened about every 3 minutes. Help.... Thanks
 

P.V.

Chief Petty Officer
Joined
Mar 14, 2002
Messages
452
Re: Evinrude O/B starts bumping over 2 RPM's

Motor is latching into "SLOW". Your "mechanic" doesn't know his OMC product, does he????? Either the engine is over-heating or the oil injection is not pumping oil. You should invest in a factory service manual, so should your "mechanic"!!!
 

ssmith1954

Recruit
Joined
May 19, 2003
Messages
3
Re: Evinrude O/B starts bumping over 2 RPM's

Thanks for your reply. I am a female person so the manual would not help me. However, I did ask the question about the oil not going to the engine. In the past when you fired it up, you got the 4th of July smoke. I get nothing. But since I am a female, of course I was immediately told I was wrong. Since the boat sat up from Sept. till now, how can I fix it if it is the oil problem.
 

JB

Honorary Moderator Emeritus
Joined
Mar 25, 2001
Messages
45,907
Re: Evinrude O/B starts bumping over 2 RPM's

Hello, SSmith.<br /><br />Why would a manual not help a female person? :confused: <br /><br />OMC's Service Manuals are written in plain English, not in some code known only to males.<br /><br />If you have no wrenching experience I can appreciate your apprehension, but being female has nothing to do with it. Useful learning is there for you if you never have or never will handle a tool. You will be able to effectively communicate with those who do work on it.<br /><br />You might be surprised at improvements you will get in service when you can discuss it with knowledge.<br /><br />You can get a lot of understanding by going to www.outboardrepairs.com and reading some of the entries on intermittent power loss.<br /><br />Good luck, and let us know how things turn out. :)
 

ssmith1954

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Joined
May 19, 2003
Messages
3
Re: Evinrude O/B starts bumping over 2 RPM's

Hi JB:<br />I have already ordered the manual. I definitely want to read up on the product, but I just meant I could not fix it personally. But then on the other hand, I have replaced the commode ballcocks in my bathrooms and an electrical light switch. My electrician/plumber thinks I am trying to take his job away from him. I am not afraid to give it a try because I cannot stand for something to be broken. And you are right, it is always good to know the correct terms to use when talking to someone. That way if you at least sound like you know what you're talking about, you stand a lesser chance of getting ripped off. It is frustrating to shell out all that money on a service call only to get no results. Thanks for the encouragement!
 

93bronco

Ensign
Joined
Nov 11, 2001
Messages
962
Re: Evinrude O/B starts bumping over 2 RPM's

well i commend you for taking on this problem. but dont feel alone just because you are a woman.<br />i shelled out 3bills to fix the problem you described. but turned out to be a combination of things that i feel "A GOOD MECH' would have noticed and told me that it needed to be fixed also, instead of telling me it was ok to run.<br />go to the search and type in "slow" or something similar and you will find some good info. good luck
 
D

DJ

Guest
Re: Evinrude O/B starts bumping over 2 RPM's

smith,<br /><br />If you can fix the toilet, you can do what I'm going to suggest.<br /><br />Take a look at the oil tank. <br /><br />1. Is there any oil in it?<br /><br />2. There is a primer bulb on top or near it. Give it a squeeze. Is it firm?<br /><br />3. If # 1 & 2 are OK, try this. Get a turkey baster you don't mind throwing away. Open the fill cap of the oil tank. Stick the baster in and draw some fluid from the bottom of the tank. Put it in a jar and have a look at it. Does it look clear or milky? If so, you likely have water in your oil tank.<br /><br />If that's the case, let us know-we'll walk you through cleaning it out and repriming the system.
 

Stassson

Seaman Apprentice
Joined
May 18, 2003
Messages
36
Re: Evinrude O/B starts bumping over 2 RPM's

I might me way off track here but I have a 175 Ev.. that did almost the same thing I dont know if the new ones have it or not But my problem was the VRO pump that pumps the oil into the gas and mixes it before the carbs. gets it. You can do most anything with the manual. I rebuilt all three of my carbs after the boat guy said he didnt think I could do it I did it and svaed big bucks and alot of time good luck
 

ob

Admiral
Joined
Aug 16, 2002
Messages
6,992
Re: Evinrude O/B starts bumping over 2 RPM's

If your engine is going in to the S.L.O.W mode the continuous alarm tone should sound.Your engine will only go into S.L.O.W if the temp sensor detects an overheat.The other continuous alarm is the "fuel flow restriction"alarm from VRO.It does not by design limit the rpms of the engine.I don't think you mentioned any alarm sounding ,which leads me down the path of a carburetion or an intermittent ignition problem.Was this engine propped to be capable of turning 5500 rpm on the pontoon before this problem arose?<br />Bare in mind that restricted or gummy fouled carbs is probably the most common problem associated with performance issues.Usually due to extended down time when not in use and not properly prepared for storage or started occasionally.I suggest having a trained mechanic perform a compression test on engine and give you the results.Good luck.
 
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