Conflicted break-in procedure?

[sutor623]

Hey fellas,

Just was wondering your opinion on engine break-in procedures. I had OBR rebuild my powerhead and was very pleased with their work, overall. I was reading over their break-in procedure and it varies greatly from the factory manual. Posted below is OBR's and Evinrude's break in procedure. OBR is saying this for ALL of their rebuilds, so I feel like it is generic, and VERY conservative. Just seems like they are protecing their own A#%!!





I ended up running thorugh 3-4 heat/cool cycles on the muffs (maybe 1 hour total run time) because I was working out some fine tuning and issues with quickstart before I brought her all the way to the lake. The good thing was that I could re-tighten down the powerhead mounting bolts after the heat/cool cycles.

After that, I pretty much stuck to the Evinrude guidelines. Except for the fact that they say for the first hour to hit the throttle and get the boat to plane, and just back down to minimum planing speed, staying under 3500 RPMs. (That was a contraindicitive statement for me, because minimum plane speed on my boat is 14MPH at 32-3500rpms.)

But Evinrude says to hit full throttle in as little as it's second hour of running, and OBR says to stay below 3000 rpm's for 6 hours!!! How could you do that and still vary the throttle position every few minutes?? You couldn't because you would keep hopping off plane.

Anyways, just wondering if you guys agree with me on just sticking with E-rude on this one? Thanks!

 

[jbcurt00]

I'd follow OBRs recommendation, esp if they warrant their work.

Now that OBR has rebuilt it, its an OBR engine not an Evinrude...

 

[Frank Acampora]

You know: There are so many different opinions on break-in. On one hand we can cite dragster engines which are run full throttle after a rebuild--but their service life is 5 seconds or a total of about 1000 revolutions and are rebuilt after each run. Racing outboards are probably not broken-in and I suspect their service life is a couple of races.

On the other hand, you want your engine to run reliably for many hours. I do agree with JBCurt: It is now an OBR outboard engine block so stay with their recommendation. Just remember that varying from the procedure by a little will not mean the engine will blow up on you. There is some leeway but racing it or high horsepower settings right after a rebuild will exceed this leeway.

Personally, I think the most important aspect of the break-in is the double oil for some period of time in order to get residual TWC-3 into the engine

 

[sutor623]

Yea, but the odd thing is that OBR recommends this procedure whether it is a 25hp single carb Mercury, or a 300HP Evinrude 8 cylinder. Just seems crazy to suggest the same break-in procedure for all motors............

I appreciate the feedback. Hopefully I don't run into any issues anytime soon. I don't think I will, but I went with E-rude's recommendations on this one............ Just threw me off that the procedure was so different for these two companies. And plus, like I said, my boat wont even stay planed at 3000 RPMs, so how could I possibly break a motor in if I can't stay on plane?

 

[jimmbo]

They just don't want you to run it at one speed all the time, or too fast too soon. The bursts of full throttle are to actually load the rings(making them scrape the cylinder walls) and then when returned to lower rpm, the rings sort of polish any freshly scraped spots, that where the extra oil comes into play. OBRs guidelines mentioned advanced spark and lean carbs/fuel injection at part throttle. The doubling of the oil makes sure there is adequate oil under this condition. Of course the extra oil in itself does lean the air-fuel mix too. Some people, easy to spot because they still walk with knuckles dragging believe that running an engine at WOT from the get go means the engine will become a high revving and high power machine. They seem to be always having their HiPower HiRevvers rebuilt.

 

[sutor623]

Haha still dragging their knuckles..... There are plenty of those out there!!

Thanks for the feedback, I love
Hearing everyone's views on this subject, keep em comin!!!