Break in - how much is really necessary ?

[Nomountainshere]

Hi there
Bought a new two stroke Tohatsu 50 - manual says 10 hours break in period. That sounds like a drag - 10 hours where I need to be calm and enjoy prolonged periods (15 mins at a time) of puttering along followed by a few mins of full-blast? - Hmmm - honestly not something I'm looking forward to.

10 hours seem like a looooooong time. I am aware that the manufacturer wants to cover all bases and avoid costly claims - however, what could be a reasonable period?

I do understand the need for warming up, letting things settle in - but 10 hours ? -well, you get the picture.

Any experience ?

[Poly]

It might well be fine, but how would you feel if it went bang at 8hrs and you hadn't followed the process or if at 30 hrs a warranty claim was rejected because the ECU data didn't have enough low revs time in it... (i'm not sure if your ECU actually has that, or how else they might show it was abused).

However FWIW I didn't find the break in period too hard. Some short periods of high revs get you on the plane and then you can back off and keep it up there (not working the engine hard).

[Xk59D]

The outboard maker will know far more than anyone on a forum, break in period is there for good reason.

[jambo]

Yep do as it says as it pays in the long term. I know your frustration having bought a new Merc 150 two years ago and having to do the ten hours seems long but my advice is the get it over with as quickly as possible.

[breezeblock]

if it was me I would probably crack on and not bother about breaking in at work nothing ever gets broken in and the stuff does 20-30000 hrs before needing rebuilt same with 2 strokes like chainsaws they never get broken in I think its a load of bollox if the engineering is that marginal that you've got to piss about for 10hrs its a poor show from any manufacturer
anyway cue the backlash who's first to want me hung for this

[Xk59D]

I'll go first then! It is far from bollocks, the rings need to seat in with heat cycles and the reason for the varied throttle is to do exactly that.

Chainsaws or the like are very different animals as they rev much higher with more oil so the ring seating is much quicker. Although the quality of Chinese built engine rings is sometimes questionable anyway but one for another time.

With my 2 strokes in my planes (50cc up to 200cc) I normally set the ring gaps myself as it makes a massive difference to the compression.

[Bigtalljv]

Isn’t it usually an hour or two of puttering then several hours of not running around at full speed? I’ve broken in two engines and it was no big thing. Also fortunate we have some good big lakes around.

Kind of a big investment to do your own thing but your call.

[breezeblock]

Originally Posted by Xk59D

I'll go first then! It is far from bollocks, the rings need to seat in with heat cycles and the reason for the varied throttle is to do exactly that.

Chainsaws or the like are very different animals as they rev much higher with more oil so the ring seating is much quicker. Although the quality of Chinese built engine rings is sometimes questionable anyway but one for another time.

With my 2 strokes in my planes (50cc up to 200cc) I normally set the ring gaps myself as it makes a massive difference to the compression.

thats a different thing altogether we are talking about mass produced stuff with preset tolerances replicated in thousands not hand built where the tolerances will be tighter because your trying to eek the last little bit of compression out of it was the correct running in done on your Suzuki?

[Pikey Dave]

A good day out in some sheltered water, big flask, warm clothing & plenty of sandwiches will get you 10 hours. I ran in my DF140 in a day.

[steco1958]

I suggest the OP does exactly as he wants, now that he has the information of what could happen if there was a claim later down the road.
Personally, I would go out early one day, full tank fuel, and potter around then do a few cycles as per the instruction book, and make sure I hit more than the 10 hours.
But it's your call !

[rubberfish]

Originally Posted by breezeblock

if it was me I would probably crack on and not bother about breaking in at work nothing ever gets broken in and the stuff does 20-30000 hrs before needing rebuilt same with 2 strokes like chainsaws they never get broken in I think its a load of bollox if the engineering is that marginal that you've got to piss about for 10hrs its a poor show from any manufacturer
anyway cue the backlash who's first to want me hung for this

I'm with you on this.
Company trucks and rental equipment are proof.
No one goes out there and pisses around in these items for 10 hours.

[Last Tango]

Manufacturers love to find reasons for not honouring warranty claims and you're kind of handing it to them on a plate.

.......my starter motor won't work....it's because you didn't run the engine in properly.....the keys stuck in the ignition barrel......it's because you didn't run the engine in properly...

And this cynicism about Chinese products. Sure we're buying a Nuclear power Station from them
On the positive side I live about 500mls from Hinckley

[Xk59D]

Originally Posted by breezeblock

thats a different thing altogether we are talking about mass produced stuff with preset tolerances replicated in thousands not hand built where the tolerances will be tighter because your trying to eek the last little bit of compression out of it was the correct running in done on your Suzuki?

Not different at all, the rings need to seat in every engine.

I don't know if my zuke was ran in correctly, it was 70 hours when I got it.

[eze]

Have a read of this,

Break In Secrets--How To Break In New Motorcycle and Car Engines For More Power


I have always run my bikes in hard & fast & never had a problem. iirc, two stroke kart engines are run in with 15 minute session.


Whatever you do, MAKE SURE YOU LOAD UP & UNLOAD THE ENGINE, if you do not put load on the engine then the bore will glaze thus leading to lower hp & more oil consumption (in a 4s)

[breezeblock]

Originally Posted by Xk59D

Not different at all, the rings need to seat in every engine.

I don't know if my zuke was ran in correctly, it was 70 hours when I got it.

for a ring to seat it needs good pressure to push it up against the bore which is generated by load

[eze]

Originally Posted by Xk59D

I'll go first then! It is far from bollocks, the rings need to seat in with heat cycles and the reason for the varied throttle is to do exactly that.

Chainsaws or the like are very different animals as they rev much higher with more oil so the ring seating is much quicker. Although the quality of Chinese built engine rings is sometimes questionable anyway but one for another time.

With my 2 strokes in my planes (50cc up to 200cc) I normally set the ring gaps myself as it makes a massive difference to the compression.

Hi there Dubris,

pistons rings do not need heat cycles (this has already been done to give the rings their specific characteristics)
Always, we need to let the engine obtain operating temperature to ensure optimal clearances though.
After that then throttle up & throttle down, all we are doing here is bedding in the piston rings by knocking off the 'high spots' asap.

I have used this recipe with all my bike engines and not had a problem. Many years ago performance bike mag compared 2 new 4s engines and the one run in hard & fast showed more rwhp on the dyno.

Having said that, Due to modern ecu's holding information then I would not want to be responsible for any problems.

If in doubt...follow the breaking in guidelines.

[eze]

Originally Posted by breezeblock

for a ring to seat it needs good pressure to push it up against the bore which is generated by load

I agree, simple as that

I will venture a little further here by suggesting that the engine does need to be unloaded to wash away there fine metal particles that accumulate under load.


http://www.mullenixracingengines.com...in-your-engine

[Xk59D]

Originally Posted by eze

Hi there Dubris,

pistons rings do not need heat cycles (this has already been done to give the rings their specific characteristics)
Always, we need to let the engine obtain operating temperature to ensure optimal clearances though.
After that then throttle up & throttle down, all we are doing here is bedding in the piston rings by knocking off the 'high spots' asap.

I have used this recipe with all my bike engines and not had a problem. Many years ago performance bike mag compared 2 new 4s engines and the one run in hard & fast showed more rwhp on the dyno.

Having said that, Due to modern ecu's holding information then I would not want to be responsible for any problems.

If in doubt...follow the breaking in guidelines.

Rings do need to seat in. No if ands or buts to that, that is done with heat cycles which equates to different loads. I.e the gap closes the hotter it gets which is why you do all compression and leak down tests on warm engines.

Anyone who thinks they do not need to run engines in that is up to them but if they didn't need run in makers wouldn't tell you to do It!

[chipko]

Originally Posted by Xk59D

The outboard maker will know far more than anyone on a forum, break in period is there for good reason.

Obviously up to the OP but for me not worth the potential risk/hassle.
Hardly a massive chore keeping under 1/2 throttle for first couple of hours then 3/4 with short bursts full for remaining eight hours. All done in a couple of outings and with 50hp on a small boat then up on the plane from outset.
More of a bummer is the £200+ first service generally required at 20 hours.

[jeffstevens763@g]

Manufactures spend colossall amounts of money and time to develop engines what do they know, your money your engine do what you want then if it lets you down only you to blame.