Proper break in on my 73 135hp.

[rodknee1231]

Replaced a piston and rod bearing but that's it. I've ran it on muffs a few times probably a total of 30 min on 32:1 and pitted around on the water once for maybe 20 only about 2 gallons put through so far. I'm using quicksilver sythetic for my pre mix. Factory service manual says to use 50:1 for break in but I'm being safe. Also says for fist 20 min do a fast idle. Then next hour no more than half throttle then the second hour plane out at 3/4 with fill throttle heat cycles. My question is do you guys think I'm ok to hammer down here n there at 50:1 ? I know alot has changed about break in procedures since this manual was released long before I was born haha

 

[rodknee1231]

Also can someone tell me why my timing light won't work on this motor as well as my inline spark tester the power pack is new motors run fine plugs have a bright spark. The light is an older Sun gun light and the inline tester is just some cheap AutoZone thing. Just wondering if anyone has seen this happen

 

[boobie]

Try the timing lite on another motor. May have a burned out bulb.

 

[rodknee1231]

Bulb looks good. Ill put it on my jeep and see what it does. What about the inline spark light ? What do you make of that ?

 

[jimmbo]

The procedures in the 1973 manual regarding break-in still apply. First 10 hours at 24:1

 

[rodknee1231]

The procedures in the 1973 manual regarding break-in still apply. First 10 hours at 24:1

It definitely does not say 24:1 thats too much oil. It says break in at 50:1 in the manual

 

[jimmbo]

If your owners manual says to use 50:1 during the break-in then use 50:1. Every motor I ever broke-in from 1965 thru 1984, the owners manuals said 24:1 for the first 10 hours. Maybe OMC of Canada had different manuals

 

[rodknee1231]

Yea I tried 24 and it was too much . ran alot better on 32

 

[emdsapmgr]

You are right on with the factory manual at 50:1 mix ratio. I tend to double oil, myself for the first tankful, before I go back to 50:1. But that's just me. It makes a little more smoke, but certainly won't hurt the engine. Keep in mind this engine one of their highest compression engines of the day, certainly higher than later crossflows. If your timing is set to the factory max timing spec, I'd be running 89 or 91 octane fuel only to insure maximum durability under your ownership. Taking into account the lousy fuel of today.

 

[rodknee1231]

Well do you think after 2 gallons I'm ready to go to 50:1 or should I fill my big tank with 32:1 there's no gas stations on the waters around here and I certainly don't wanna do like 5 gallons and then only be out out for a hour or 2 then have to leave again because I ran out of gas