Rebuilt engine break in

[Josher]

Hi, I'm looking for some advice on the proper break in procedure for my 2004 75 merc 2stroke I just had rebuilt.

From what I know, I'm supposed to run 50:1 oil/gas mixture for the first two tanks. The engine is oil injected. Then I'm supposed to:
- idle for 10 mins,
- then vary throttle not going over 3500 for 20 mins
- then run at various rpm's again for the next 30 mins with short bursts of WOT
- then 10 hours of normal operation with no WOT and vary engine speeds.

Am I on point? Anything else I should know?

Also, may be a dumb questions but am I supposed to do this consecutively and go for A 10 hour boat ride? Or can I do it periodically while I fish for the next few days...

Thanks

 

[carholme]

Re: Rebuilt engine break in

I can send you the owners manual if you send me a PM with your email address. Do you have the Mercury service manual. I can send that as well.

From the owners manual:

MODELS WITH OIL INJECTION
Engine Break-in Fuel Mixture - Use a 50:1 (2%) gasoline/oil mixture
in the first tank of fuel. Use of this fuel mixture combined with oil from
the oil injection system will supply adequate lubrication during engine
break‑in.
Engine Break-in Procedure - Vary the throttle setting during the first
hour of operation. During the first hour of operation, avoid remaining at
constant speed for more than two minutes and avoid sustained wide
open throttle.
MODELS WITHOUT OIL INJECTION
Engine Break-in Fuel Mixture - Use a 25:1 (4%) gasoline/oil mixture
in the first tank of fuel. After the break‑in fuel mixture is used up, use a
50:1 (2%) gasoline/oil mixture.

Engine Break-in Procedure - Vary the throttle setting during the first
hour of operation. During the first hour of operation, avoid remaining at
constant speed for more than two minutes and avoid sustained wide
open throttle.

Gerry

 

[Josher]

Re: Rebuilt engine break in

Thanks. I have the manual and thought there was more to it than that. I broke it in this weekend using the method I described.. hopefully it's all good!