Question re break in.

[eliminatedsprinter]

My boat just got a new (rebuilt) powerhead and it's just out of it's 10 hr builder required break in period. I have 2 12 gallon tanks and each still had about 3 gallons of premix in it, that I had to run it on during the break in period, in addition to the oil injection.
My question is: I seem to have lost about 800 rpm and 10 mph from what I could do with my old powerhead. Is that normal for this stage of the game or do I have another problem?

[HavasuDreamin']

Are you running the same prop? All other conditions the same (ie: amount of people in the boat, gas, etc.)? Are you able to open it all the way up and hold it there for a little bit? Is the motor built to the same specs as before........compression, etc.?
One thing you may want to look at is your throttle linkage. Pull the cowl and see if your butterflys open all the way up when you push the throttle all the way down. Sometimes it is the little stuff that gets messed up.
If none of that is the answer, then your powerhead may be the problem, but I would have expected them to dyno the motor. After 10 hours, you should't be down on power.

[eliminatedsprinter]

Thanks.
Yes it is the same prop. The powerhead builders wouldn't warrenty it if he didn't re jet the carbs to run a bit richer and there is still a little extra oil in my fuel otherwise everything should be the same.

[HavasuDreamin']

Well then.........jets and extra oil could be the culprit. Jets for sure.
Does it run well........start and idle well, run top end well? If so, I would leave it alone until it is well broken in and all the premix oil is long gone. After 3-5 hours of running with no pre mix, I would pull a spark plug after a top end run, and check it out. If it is real dark, you could probably gain some of that RPM back by going down one size on the jets.
To be honest though, as long as you are getting 55-60 mph out of your set up, running a little rich won't hurt a thing. :)

[eliminatedsprinter]

It does start and idle ok. However, it dosen't even get 55-60. The water was pretty sloppy so, I wasn't able to really run it out and play with my trim much etc. But it basically felt like it did with my old crappy aluminum prop and it seemed to be running out of legs around 51-52 mph by gps and a full 8-900 rpm less than before on my tach.
I called my mechanic and he said pretty much what you just did. He said he also had to set the timing back a bit as well, for me to keep my warrenty. He was concerned by how much speed it lost. He says he is going to call the co that made it and see if there are any other changes from the stock powerhead.
P.S. The fuel consumption was way up as well (from the bigger jets no doubt). Now my 2 12 gallon tanks seem downright dinky.

[HavasuDreamin']

Larger jet, and decreased timing are definately affecting your RPM's without a doubt. My question to your engine builder would be ........why can't you put it back to bone stock and warranty it? Why does it have to be rich on the jets, and retarded on the timing to get a warranty?
Good Luck.........I think you are on the right track.

[eliminatedsprinter]

Originally posted by HavasuDreamin'
Larger jet, and decreased timing are definately affecting your RPM's without a doubt. My question to your engine builder would be ........why can't you put it back to bone stock and warranty it? Why does it have to be rich on the jets, and retarded on the timing to get a warranty?
Good Luck.........I think you are on the right track.
Thanks.
Those were my first questions too.:cool: They said it was because todays gas isn't as good as it was when my motor was first made in 1985...:rolleyes:

[You Te]

Sprinter,
I'm sorry but those rebuild guy's sound like circus monkeys.
No timing and lot's of oil will let the motor live. but you won't be happy with the performance.
Ask the guy's to put it to stock specs and you will run better fuel.
If they replaced the pistons and or rings and cleaned up the bores or re sleeved some holes rich is ok for 10 hours. After that it's time to hammer it.
The question is, why did the motor have a problen to begin with.
Sometimes if you let the motor sit for a long time without starting it the carbs will gum up and you will stick a piston. That's why EGT's are nice.
You Te

[eliminatedsprinter]

Originally posted by You Te
Sprinter,
I'm sorry but those rebuild guy's sound like circus monkeys.
No timing and lot's of oil will let the motor live. but you won't be happy with the performance.
Ask the guy's to put it to stock specs and you will run better fuel.
If they replaced the pistons and or rings and cleaned up the bores or re sleeved some holes rich is ok for 10 hours. After that it's time to hammer it.
The question is, why did the motor have a problen to begin with.
Sometimes if you let the motor sit for a long time without starting it the carbs will gum up and you will stick a piston. That's why EGT's are nice.
You Te
My moter siezed up last Nov. It seems it threw a wt from the flywheel. My mechanic bought a commercially rebuilt powerhead to replace my old one . He also replaced the flywheel and VRO pump. The co that sold him the powerhead required him to re jet the carbs and set back the timiming in order for them to warrenty the powerhead. You can best believe It's going to be re jetted and set back up as soon as the one year warrenty is over. This season (for warrenty reasons) I'm pretty stuck. But during the off season, I'll take it to Stoker and have them dial it back in for me. :cool: According to the previous owner and the guys at Eliminator, Stoker rigged my boat when new, so they still would be the best qualified folks to get it's performance back up.......:cool:
Looks like there will be no smoking jet boats for me this season. It was kind of fun (after I found the right prop) to pull away from jets with big blocks (those that were not blown, that is) with just a V 6 150...:D :cool:

[racer]

How much bigger jet did they put in the engine?

[You Te]

Sprinter,
racer is Al Stoker, answer the man.
You Te

[eliminatedsprinter]

Originally posted by racer
How much bigger jet did they put in the engine?
Sorry, I couldn't answer right away. I wasn't on the net all weekend.
The jets are increased by 2 one thousandths and the timing was retarded 2 degrees.
Thanks:cool:
P.S. The motor is an 85 E rude XP 150 V 6.

[eliminatedsprinter]

I'll be off the boards for a little over a week. I'd love to get more ideas re this problem. Just don't feel ignored if I don't respond back to any posts right away. Thanks.:cool:

[eliminatedsprinter]

Originally posted by You Te
Sprinter,
racer is Al Stoker, answer the man.
You Te
Contaced him through PMs. He was helpful. He will be getting my biz in the future, you can bank on that...:cool: