question about breaking in power head

[fishingdave]

I just finished doing a full rebuilt to my 1989 90hp crossflow, compression 135- 140, engine starts right up and runs smooth. I have a couple of questions<br /> <br />first what is the the proper way to break in a new power head with wiseco pistons?<br />second i was told to set the advance timing to 24 and not 28 when the motor is finally broken in, is this a good thing? and why?<br /><br />Third once i shut off my outboard, 15 min later, some brown-green ooozz come out of where the prop is, ( it looks like gas,oil mix) is this normal? I am runing a new vro pump and mixed the gas 100:1.<br /><br />all the help would be greatly apreciated.<br /><br />thanks<br />dave

 

[Mark42]

Re: question about breaking in power head

I think the basic break in proceedure is to run double oil, that is run 25:1 instead of 50:1. So if you have a VRO, it is putting in oil at 50:1, you need to add oil to the gas at 50:1 for a total mix of 25:1.<br /><br />From my 93 owners manual: <br /><br />First 10 minutes - operate at fast idle only. Check water pump indicator.<br />Next 50 minutes - operate engine at 1/2 throttle, no more than 3500 rpm. Change engine speed at least every 15 minutes, DO NOT HOLD CONSTANT THROTTLE SETTING. <br />Second Hour - Use full throttle to plane boat only, then back off to 3/4 throttle. At intervals apply full throttle for up to two minutes, returning to 3/4 throttle for cooling period.<br />Next Eight Hours - Avoid continous full throttle operation for extended periods. Change engine speed every 15 minutes.<br /><br />Be sure to check that the oil level in the VRO tank is dropping indicating that it is using oil. Maintain a total mix of 25:1 for the first full 10 hours of operation.<br /><br />I think this is pretty much their advice on all break-in's.

 

[red boat]

Re: question about breaking in power head

fishingdave, I rebuilt my 1990 Evinrude xp-200 and was told by Wiseco to idle the engine for 2- yes 2 hours before applying any throttle. I thought it was a really weird breakin experience. They told me letting it idle for 2 hours would allow the pistons amd the cylinders to "form" to each other, then follow Mark 42's advice and you should be ok. Good luck

 

[Mark42]

Re: question about breaking in power head

Is there something special about Wiseco pistons? I as because I know the pistons used in my motor's rebuild were forged, not cast like (I believe) the factory pistons are and written breakin proceedure from rebuilder was exactly the same as what Evinrude says in the owners manual.

 

[R.Johnson]

Re: question about breaking in power head

Wiseco advises that you replace the thermostats, or verify that they are working at idle. The engine should be somewhere between 140 - 160 degrees at idle. Otherwise break it in as Mark42 says'. The reason for the correct idle temp. is to prevent a cold sieze.

 

[fishingdave]

Re: question about breaking in power head

thanks i will do that, also what about backing off the timing to 24 is that a good thing to do?

 

[R.Johnson]

Re: question about breaking in power head

With out looking at the manual, I don't know what the correct timing is for your engine. For your engine , it will not hurt for the break-in. If you want your engine to be a true 90 HP, put it back where it belong's. Also get the RPM's up where they belong with the correct prop. That should be about 6000. If you don't, you will be taking it apart again.

 

[angus63]

Re: question about breaking in power head

Not a bad idea to retorque the heads after 10 hrs either.<br />good luck