200 hp. Lack of power after warm up

[Yank]

I have a 1986 200 XP Evinrude that has 50 hrs. on it sense it has been rebuilt.It ran good for the first 35 hrs.This is what it is doing,when you first start it up at the lake and take off it runs great. I can run it as long as I want and it won't miss a lick. After I stop, for at least 10 min.The engine will start but when I give it the trottle it dies out. If I rev the motor up for 5-10 seconds and jamb it into gear as the r.p.m.,s go down it will go.I was told that Evinrude had some design problems with this engine.There were several things that the factory came out with to correct this problem, I have been told that all of those things were done to my engine except for one. My engine has large port carbs on it,I'm currently having the carbs change out to small port. I have already replaced both power packs,all the thermostats, fuel pump,complete tune up, I have checked the timing and advance while the boat was being operated.The oil pump has been removed and I mix all of gas.I put O.M.C. 2+4 additive during storage.I'm running out of solutions and money,HELP!

 

[Kenny Bush]

Re: 200 hp. Lack of power after warm up

Yank, you may want to check the Reeds for wear(or slightly open condition). Sounds like the motor is not aspirating correctly. If the reeds are wore out or slightly open, the motor loses it's continual fuel flow. The atmospheric condition in the motor cannot be maintained. Once motor starts revving up, the fuel flow is going, but once you stop or slow to an idle it dies. I have found that if you move the throttle very slowly up and down through the RPM range, it will run better. If you move the throttle up and down quickly through the RPM's, you will find it does not run (aspirate or breathe) properly. Good luck........ BushCat

 

[Yank]

Re: 200 hp. Lack of power after warm up

Bush Cat, The motor will not trottle up even if I ease into it. It doesn't matter how slow I try to start out. I have a 24 pitch 3 bladed Raker prop that has some minor damage, that might affect the cup of the prop. I was wondering if that,and the fact that the motor has some wear on it, would be putting to much drag on the motor. The motor will operate fine out of the water in a test tank. You can put in gear and stomp it and it never misses a lick.I was thinking that a smaller prop might help also,21 pitch?

 

[Kenny Bush]

Re: 200 hp. Lack of power after warm up

Yank, I don't think that prop is the culprit.........Even with a whole blade missing, it will rev up....You must have a bass boat with a Raker 24. If this is the case, I think pitch is ok...If your boat is a heavier runabout, a 21 or 19 pitch prop would be the usual. Did you have the compression checked? I would think that was the 1st thing to check. Let us know the compression so that we can know the motor OK..After that , I move to the timing, especially the maximum spark advance. Let us know......... And also, Motors always run better out of the water........Best to test on the water or in a test Tank.....Good Luck.....BushCat