1998 evinrude 70 hp rpm limited

Thomas272

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Does anyone know if a evinrude 70hp is equipped with a rev limiting device built into the ignition system? I have one that with not rev over approx. 2500 rpm. I cuts in and out at exactly the same rpm. Not fuel. It acts exactly like a rpm limiter. Runs fine otherwise.
 

Thomas272

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Found that overheat switch is bad causing ignition system to limit rpm at 2500 instead of 6700. Unplugged temp. Switch to confirm. All is good when unplugged. Now I need to locate a new one. No luck so far.
 
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the easy way to tell if you have an RPM limiting pack is by looking at the #'s on the pack itself. CD means no limit, and CD2 means it's limited and usually tells you on the pack what it's limited to, but only for the rectangular older ones I believe.
 

flyingscott

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the easy way to tell if you have an RPM limiting pack is by looking at the #'s on the pack itself. CD means no limit, and CD2 means it's limited and usually tells you on the pack what it's limited to, but only for the rectangular older ones I believe.
CD2 means 2 cylinder, CD3 means 3 cylinder. If the pack has S.L.O.W it will say CD3SL on it. Most packs for 3 cylinder looper are rev limited to 6200 rpm.
 
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You are correct. I screwed that up. should've said cd2, then L in there, and usually a # for RPM. Ie. CD2/62L... 2 cylinder with 6200 limit.
 

Thomas272

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I can get the engine to act up in the driveway with muffs on the engine. Right from a cold start, rpm is limited to 2500 rpm.
So overheating not likely, good water flow out from all passages. Unplug the temp. sensor and issue goes away. I'm looking to purchase a new one Evinrude cataloged part # 0585023 picture attached. so far no luck finding one.
 

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flyingscott

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Is this all on muffs? There is a test for that switch. Do you have a manual?
 

Thomas272

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So purchased a new OE temp sensor and installed it. The rev limiting (2500 rpm) problem went for constant to intermittent.
This is making me a little nuts. I'm a 30 automotive master technician skilled in electrical/ computer diagnostics. That said this is a simple normally open temp. sensor that should ground (the tan wire) if an overheat is detected. Sensor unplugged the engine will rev. to over 6000. Sensor plugged in (2500 rpm sometimes, sometimes 6k+). Ohm out the sensor to ground its open. I also have a buzzer in the shift handle and a temp. light on the dash, neither come on when the engine is acting up. I do not have a repair manual or a good wiring diagram for this engine. There is also a white wire on this sensor but do not have a good description of operation for this sensor/cdi box. This problem occurs right from a cold start, engine cold or a any point throughout using the boat. Overheating is not a possibility. This happens in the driveway on the muffs or in the water under load. Your expert advice is appreciated.
 
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