mercury 250 four stroke break in wot question

[fishyfeet]

manual says keep under 4500 rpm first two hrs but every 10 minutes wot so does that mean motor trimmed down with jackplate down get to 4500rpms for one minute or trim some and try to get to 6000 rpm

[Pulsare2020]

manual says keep under 4500 rpm first two hrs but every 10 minutes wot so does that mean motor trimmed down with jackplate down get to 4500rpms for one minute or trim some and try to get to 6000 rpm

I believe Don had a post on 4 stroke break-in, in the frequently asked questions on the 4 stroke forum. I think the manual meant to run it at 6000 rpm for no longer than 1 minute, every 10 minutes or so. I don't think it matters much on what combination of throttle and trim you need to hit at least 6000 rpm, the rpm is more important than the trim or throttle setting to seat the rings.

[mactlman]

per don:
For the First Two Hours of Operation: Start the engine and allow it to reach operating temperature. Get the boat on plane, and operate the engine at up to 4500 RPM's (Important: Vary engine RPM's every 2-5 minutes). Run the engine to FULL THROTTLE for 60 seconds once every 10 minutes (approximately).

Additional Recommendation: Though not listed in Owner's Manuals, it is an excellent idea to have the engine make at least two (2) complete HEAT CYCLES during the first 2 hours of operation. A heat cycle consists of: Ambient temp, start engine, come to operating temp, run engine for at least 5 minutes on plane, return to idle, stabilize engine temp, shutdown engine and allow to cool to ambient temp. Note: Heat cycles CAN be done on different days.

[fishyfeet]

thanks wording i guess in manual wording should read only time over 4500 rpms is doing the one minute wot every ten minutes

[EuropeanAM]

per don:
For the First Two Hours of Operation: Start the engine and allow it to reach operating temperature. Get the boat on plane, and operate the engine at up to 4500 RPM's (Important: Vary engine RPM's every 2-5 minutes). Run the engine to FULL THROTTLE for 60 seconds once every 10 minutes (approximately).

Additional Recommendation: Though not listed in Owner's Manuals, it is an excellent idea to have the engine make at least two (2) complete HEAT CYCLES during the first 2 hours of operation. A heat cycle consists of: Ambient temp, start engine, come to operating temp, run engine for at least 5 minutes on plane, return to idle, stabilize engine temp, shutdown engine and allow to cool to ambient temp. Note: Heat cycles CAN be done on different days.

^^^ Right there

There is absolutely nothing in the Break-In instructions for your 4-stroke that indicates anything about tucking in, etc.

[jrh_67]

This was confusing for me also when breaking in my motor. Dealer said to run it wide open as in beyond 4500 rpm as stated here for a about a minute every ten minutes. He did tell me to tuck it in though when running 4500rpm and under and vary speed.

Personally I would listen to what Don said and treat it as gospel...