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Replacing powerhead on 90LTR 2 stroke Yamaha

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Dave1775

New member
Any advice from the boards about how to start my new power head off right? I've read double oil for a while, but looking for anything that will help me start off right.

Thank you
 
Year and exact model # ?----So you bought a rebuilt powerhead and put all your old stuff on it ?---Tell the whole story here.
 
2008 90TLR sorry mixed up the model in my post. I sprung for a new power head not rebuilt.

Just looking for advice on hours 1 to whenever... things I can do to make sure I treat it right from the start.
 
Well not specific to outboards, but I know with other 2 cycle engines it is common for people to add a little extra oil for the first few hours. Not double it though...you want (need) some friction for the rings to seat properly.

A 90TLR should be oil injected so you can add a litte extra to the fuel if you feel the need to. Also, be sure to run the motor on 50:1 pre-mix at first. It takes a few minutes for it to prime the oil pump and get oil flowing to the carbs.

Some people will say to idle it for a while at first, and some will say just use it as you normally would....

personally, I like to go a little easier on it at first but definitely don't baby it. I will idle it for a little bit to get it up to temp then start lightly applying a load to it. then bringing it back to idle for a second. I like to vary the RPM for a bit and do not let it stay at a constant RPM for too long. After idling it around for a bit I would get it up on plane shortly then set it back down. do this several times. this will really help to generate heat and load and will help the rings seat.
eventually, get it up cruising 35-45,00 range then throttle it down till the boat starts to sit down, then bring it right back up to cruising speed again..

Personally I like to do several heat cycles through a new motor. (start-run-turn off-cool down-repeat).. so I might do this 2-3 times before really taking her wide open for an extended period.


Like I said, this is not specific to outbaords but rather other 2-stroke engines, But I have done this kinda routine with many of them without issues.
 
The first 10 hours keep the RPMs under 2500 w/occasional increases as stated above. Then just drive it normally but not wide-open throttle a lot for the next 10 hrs. Then just use it as you would. I would also idle it for 5-10 minutes after a long run before turning it off.
 
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