# new tohatsu 20hp break in ?



## 96kdx200 (Apr 3, 2015)

first 4 stroke and first new motor does it really need a ten hour break in and is trolling for long periods ok during break in :?:


----------



## Johnny (Apr 4, 2015)

nah - these companies spend millions of dollars in research and development
of their products and often give free advice in the initial use of their products to ensure
you have a very fulfilled boating experience for a long time.
The advice is just a guideline. Use your own judgement and motor along accordingly.




sarcasm ? possibly
Truth in the manufacturers suggestions ? probably
What is the worst that can happen if you go WOT in the first 30 minutes ??
ohhhhhh metal chips in the gear case oil would be bad.
piston rod through the crank case - not so good either.
Your motor - you decide
But honestly, long trolling would be the break in


and :WELCOME: to Tin Boats !!
Stay awake, take notes, pay attention and you will do well.


----------



## nowgrn4 (Apr 4, 2015)

I've heard clowns say Run it like you stole it for break in. They are usually shade tree hackers. You know the type, Manufacturer calls for 50:1 oil but they know better and run more. Manufacturer calls for 50Ft/lbs Head torque. More is better right? They will torque to 60ft/lbs. Manufacturer calls for 19 degrees BTDC timing spec, silly fools 21 degrees is more better. 

Unlike clowns on the web manufactures spend millions on R&D and they don't want their product to blow up and damage their reputation. Especially under warranty.
Again, follow the manufactures recommendations.


----------



## DrNip (Apr 4, 2015)

I ran mine as close as I could to the ten hour recommendation. Let me tell you it was rough. That 10 hours felt like forever! I've heard people say you don't have to but it was my $4300 spent and I didn't want to take a chance on word from some joe blow who didn't spend the money.


----------



## TNtroller (Apr 4, 2015)

The main objective of the break in period is to run the motor at varying rpm speeds, and not stay at one rpm level for extended periods such as trolling. Follow the manual, just don't take any rods with you, do you remember seeing some spots you wanted to check out sometime. Engine break in period is a great time to do that, all day to do it and no where to go.


----------



## 96kdx200 (Apr 4, 2015)

guess ill wait for a calm day launch out of newburgh and head to Kingston on the Hudson round trip should be close 1/2 to 3/4 throttle thanx


----------



## nowgrn4 (Apr 5, 2015)

The manufacture dictates oil changes after the first 20 and again at 100 hours. I would do another change at 60 hours just to be safe. It's only a quart. Cheap insurance.


----------



## lovedr79 (Apr 5, 2015)

I ran my merc 20 which is the same as tohatsu but more expensive. I ran mine for an hour below half throttle. Then ran it 3/4 a couple minutes. Shut iit down fished until it was cold. Then did that a three times to heat cycle it like we di with dirtbike motors. Then game on. No problems


----------



## 96kdx200 (Apr 5, 2015)

ya looked at mercs but couldn't pay the extra $400 for a sticker


----------



## lovedr79 (Apr 7, 2015)

when ordering parts for mine i ordered the tohatsu parts. LOL! cost about half of merc parts


----------



## turbotodd (Apr 7, 2015)

was explained to my by a factory rep that the break-in period has a lot to do with rings and cylinders. Specifically "seating" the rings to the cylinder. Not for ring seal, however. The wear face of the piston rings are kind of rounded when they're new. The cylinder is obviously "flat", in other words it's not tapered or anything when new. Because the rings are barrel-faced, there is not a lot of contact between the ring face and the cylinder. The piston dissipates combustion heat from the crown of the piston into the rings and from the rings into the cylinder wall, which is cooled by water on the outside. If for some reason the rings aren't seated very well to the cylinder, possibly due to manufacturing tolerances or whatever, the pistons can't dissipate the heat of combustion fast enough to cool the piston tops, which can cause them to run hot. It's more pronounced with 2 stroke engines that have a power stroke every revolution, therefore it's much more important to break them in as the manufacturer specifies (read: ETEC). Lean run, combined with 2 stroke, could be disaster if all doesn't go quite right. 4 stroke isn't such a big deal because at TDC at the end of the exhaust stroke the cylinder is just starting to intake a cool air/fuel mixture which helps cool the piston. 

That's how it was explained to me, the easiest way I know to explain it here. HOPEFULLY nobody's confused. Break it in properly. I'm one of those goons who breaks the race car engines in the right way. Fire it up, check for leaks, heat cycle it to 200-220 degrees, shut 'er down and go to the races. From then on, the break in period is wide open full load. Never leaked down more than 5%, never broken or burnt anything up but these are 100% different than outboards. Outboards run at full load, full RPM continually. Cars (well mine) runs full load for 5 seconds and then it's idling. Round trackers run full load for a little while and are on and off the throttle a lot. All 3 totally different from each other and require different types of break in.


----------

