breakin procedure for a rebuild

[plumbjobber]

I earlier posted about buying a rebuilt Johnson motor and trading in my old rude, I took the advice offered and traded my old rude for this 1990 rebuilt johnson. On the way home put some new gas in the tank,added oil at 50-1, and then added a little more as advised by wrench whom I purchased motor from. I stopped at landing on way hoem and dropped her in, ran great, with my brother in law and myself in boat planed right out and ran like a top. I varied engine rpm's as instructed.and ran up and down the river for approxiamately 30 minutes. My question is this how long is the break-in period for a rebuild of this nature? This is a 1990 60 hp Johnson bored .30 over, new pistons rings etc. How long before I can run WOT and hold her there?

 

[Solittle]

Re: breakin procedure for a rebuild

You are looking at 10 hours total. The first 30 minutes or so should be at no wake speed. The next 30 should be to bring it up on a plane & throttle it back & forth keeping the rpms on the low side. For the next 9 hours it is running at various rpms for short periods of time. I would not hit WOT until at least 5 hours. The next five is more of the same with longer periods at WOT. All this at 25:1 fuel oil mix. After 10 hours drop back to 50:1 and let her rip as long as you want.

 

[plumbjobber]

Re: breakin procedure for a rebuild

the wrench I bought her from, put her on another boat and ran her in the weekend before she was put on my boat, he said it was ok to go wot for a short period, that he had ran her in for 5 or 6 hours or so. He said I should run a little extra oil for the first tank, but did not mention going to 25:1, maybe i need to add a little more oil to this tank before i put her in tomorrow. Thanks for the input. Also what rpm's should i be running at wot? I am waiting for a tach harness i had to order and will not run her wot for any length of time till i get the tach hooked up, but would be nice to know what wot rpm;s should be.

 

[Solittle]

Re: breakin procedure for a rebuild

Don't know your motor but most Johnnys have a WOT at 5500 rpm.

 

[WillyBWright]

Re: breakin procedure for a rebuild

with the 50:1 premix in the tank and the VRO adding oil at around 50:1, that's your 25:1.