RPM problem with Evenrude 15hp 4-stroke.

[Threadfin]

bought a new Evenrude 15hp 4-stroke in 1999. Since then I've had a number of problems, including a new ignition module, at considerable cost. On my first trip after replacing the module, I could only get maximum rpm's when the engine was cold. After trolling for one or two hrs, I noticed that when I gave it full throttle I only would get about half the rpm's. This only happened when wide open. Trolling speed is fine.Has anyone had a similar problem with this motor?

 

[OBJ]

Re: RPM problem with Evenrude 15hp 4-stroke.

Hi Threadfin welcome to iboats forums....found yer post way down the page and sounds like ya' may need some help.<br /><br />What the problem sounds like is that your SLOW system is engaging to keep the engine from running at high rpm. The SLOW system kicks in if the temp of the engine goes high or for some reason the oil pressure drops. Since you have recently replaced the ignition module and this problem cropped up, it may be that the module is at fault or by coincedence either the temp sender or the oil press sender has gone bad. Both senders will have a tan wire coming from them to the engine harness. Disconnect one or the other and try the engine to see if you get WOT. Test both senders. <br /><br />If you get WOT after disconnecting the a sender, ground the lead that goes to the harness and see if the engine rpm drops. If it does, the sender is at fault.<br /><br />An OEM service manual would help you troubleshoot the problem.<br /><br />Keep us posted....Good Luck.

 

[Threadfin]

Re: RPM problem with Evenrude 15hp 4-stroke.

Thanks for your help, OBJ, Do you know where I can find the manual you suggested.<br /><br />Thanks,<br />Threadfin

 

[DHPMARINE]

Re: RPM problem with Evenrude 15hp 4-stroke.

Threadfin,Try to get the Evinrude manual from the dealer you bought the motor from.Aftermarket manuals are fair,but generally....too general.<br />DHP