Running in a new motor

[Stigomery]

Hi,

I'm keen to understand the mechanics of running in a new motor. I understand from Honda that the first 15 minutes should be idle, then 45 minutes no more than 2-3k rpm, then 60 minutes no more than 4-5k rpm, then 8 hours of no more than 5 minutes constant at full whack...

So my question is this, I'm guessing those first 2 hours are crucial and therefore do they need to be done as one outing, i.e. is it best to run the engine continuously for those first 2 hours or is it acceptable to potter somewhere at idle/low revs, stop, then restart and do the next 30 minutes elsewhere. Then do the next hour another time... etc.?

Thanks,

Stig

[jeffstevens763@g]

Originally Posted by Stigomery

Hi,

I'm keen to understand the mechanics of running in a new motor. I understand from Honda that the first 15 minutes should be idle, then 45 minutes no more than 2-3k rpm, then 60 minutes no more than 4-5k rpm, then 8 hours of no more than 5 minutes constant at full whack...

So my question is this, I'm guessing those first 2 hours are crucial and therefore do they need to be done as one outing, i.e. is it best to run the engine continuously for those first 2 hours or is it acceptable to potter somewhere at idle/low revs, stop, then restart and do the next 30 minutes elsewhere. Then do the next hour another time... etc.?

Thanks,

Stig

when you get your new engine its fully explained in the manual i am running in at the moment with my Suzuki do it to the book as they can tell what its been running at with a PC hooked to it if you have any warranty issues. running at lower RPM is OK, the run in period is while the engine beds in ie; piston rings with the cylinders etc too much heat can be generated if at full whack causing the engine to seize during this time. variation in RPM is needed that's why it goes up in RPM mine finishes at 10 hours i am on 4 hours now and with my set up 1/4 throttle is plenty.

[Fenlander]

You are right Stig, that first two hours is far better done in one if nothing else to know that more restricted running is compleed in favourable circumstances. With 20hp on a SIB the final 8hrs will be easy as it will push you along nicely without huge effort on the part of the motor.

As Jeff says varying revs is the key.

[uncle al]

If you are running it in any container, you must keep the water cold.If the water starts to get warm shut the OBM down .

[jeffstevens763@g]

my engine is Suzuki 25
break in time 10 hrs
tick over 5 mins from cold always.
run in gear at tick over 15 mins
next 1 hr 45 mins less than 1/2 throttle.
next 1 hr at 3/4 throttle
next 7 hrs at desired speed but not at full throttle for more than 5 mins at any time

[paintman]

Discussed at some length here: http://www.rib.net/forum/f36/running...ard-69301.html

[Pikey Dave]

Originally Posted by Stigomery

Hi,

I'm keen to understand the mechanics of running in a new motor. I understand from Honda that the first 15 minutes should be idle, then 45 minutes no more than 2-3k rpm, then 60 minutes no more than 4-5k rpm, then 8 hours of no more than 5 minutes constant at full whack...

So my question is this, I'm guessing those first 2 hours are crucial and therefore do they need to be done as one outing, i.e. is it best to run the engine continuously for those first 2 hours or is it acceptable to potter somewhere at idle/low revs, stop, then restart and do the next 30 minutes elsewhere. Then do the next hour another time... etc.?

Thanks,

Stig

Most engine wear occurs at starting & warm up. If you repeatedly start the engine & allow it to cool you won't do it any good, especially at break in. Even a run in engine should be allowed to warm up before giving it "the beans"