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Awesome, sounds like your cam is broken in just fine. If you haven't changed the oil yet after cam break in then do that before taking it out on the water. Your break in oil and filter are full of metal from the cam and lifters wearing together along with assembly lube and any other junk you don't want in the oil. You want clean fresh oil for actually running it under load.
Rings can take a little while to seat. Two schools of thought on this. One is take it easy and vary RPM so they gently wear in to the bores. The other is run it hard, several hard pulls working up to WOT and back off letting engine braking keep revs up a bit while slowing down (that bit not as practical in a boat, but some props do have a lot of bite), at first stopping at lower RPM then working up to higher RPM. The theory is more aggressive acceleration and deceleration yields higher cylinder pressures which helps the rings wear together to the bores more quickly.
I used to be of the former crowd, generally going pretty easy but varying RPM and load as much as possible. Now I'm slightly more favoring the latter method as I believe it seats the rings more quickly. I've driven engines both ways during the break in period but don't think it makes a big difference. Parts wear together fairly quickly either way and I've never had a problem with ring seal using either method. Pick your poison, I won't advise you one way or the other aside from avoid extended idling for the first 20 hours or so. Idling, particularly before the rings are fully worn in and seated, can build up carbon and blow by between the rings and lands. Change the oil immediately after cam break in and again after 20-25 hours. After that go to your normal oil change interval.
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That makes a lot of sense. Thanks for that explanation. I've heard of both schools of thought as well, and that's why it was confusing me. I'm going to continue reading on both methods, but just for argument sake, let's say I go with the hard pulls. How long does this need to go on? 10 pulls? 5 hours? I totally get the "don't let it idle" thing and will be avoiding that regardless of the method.
Awesome advice. This thread should be stickied just for that one post.
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^ +1.
I have a question about the no idling. I have to do the 20 hour break in on my new motor (cam was done by marina). When I plop my boat in the harbour we have to go through a no wake zone (idle) to get to the lake, it's about a 2 minute stretch. Will that be an issue?
Sorry Titan, not trying to hi jack.
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No worries with a short no wake zone like that. When I say extended idling I mean more like 15+ minutes at a time. So long as the cam is already broken in you're fine. Letting it idle for a few minutes at the dock or through a no wake after dropping it in is good to get some temperature in the block and oil before putting a load on it when getting on plane. The first 20 hours or so on an engine are not nearly as critical as the first 20 minutes of cam break in.
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Onto other projects. I replaced the steering cable and helm this past weekend. The most aggravating part was fit the bezel under the steering wheel. I had to make several fabrications to make it all work. But I think the end result looks great and it seems to function real well.
Just a couple more weekends and I'll be doing the engine break-in on the lake.
http://unumemarketing.com/boat/steering_wheel.jpg
http://unumemarketing.com/boat/helm.jpg
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Break in went well. Everything worked great and all gauges are spot on. The only issue was the engine had a hard time turning over when starting when warm. At first I thought the battery wasn't charged or I had some wiring issue. But after checking everything out I determined that the timing was off. It was retarded by a degree or two. I had set the timing by feel initially because I didn't have a timing light and because I didn't want it to sit at idle too long until it was broke in. The timing is now set at 9 degrees BTDC and the engine turns over as it should.
Once we get some rain free weekends it'll be more lake tests to make sure everything is as it should be. And oh yeah, the steering was like butta.
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Awesome. Glad to see you got it all in and running in time. I will probably do a refresh on my engine next winter when I pull it out.
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False alarm. It's not doing right. Went for another lake test today and was stuck on the lake for about an hour. It starts and runs well from the beginning. After 10 minutes of running and I shut it off and it started again easily. I ran for another 15 minutes and shut it off again. Suddenly the problem of not being able to get the engine to turn over was back. It turns the engine over for half a revolution or so and then stops. Putting both batteries to it doesn't make a difference. The starter seems very hot to the touch. I got going again by pouring cold lake water over the starter housing and cooling it down. But once it was running again it was hard to keep idling. I made it back to the dock fine (anything above 1,200 rpms runs great). But idling around the dock was very difficult and it kept cutting out. It would turn over fine and restart. Huh?
Thoughts? And for the record, the starter is 10 months old - a marine starter from DB Electrical.
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So many things...
Vapor lock? Check your timing.
Firing order? Check your distributor and plug wires.
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Is it the big old plunger style or the newer mini high torque starter? I have had bad luck with the old starters. I ditched them in 3 boats and have the mini high torques, never had a problem since. They draw less amps than the old ones and turn the motors over faster... Make sure you use a conducting paste such as never sieve against the face of the starter and the the bell housing and use never seize on the boats, this really helps move the electrons :P