| T.R | Title | User | Personal
Name | Date | Lines |
|---|
| 111.1 | needs more rpm's | CRISTA::CERIA | | Mon Aug 15 1988 14:31 | 16 |
| RE .0
I wouldn't waist the money on buying a new prop. I would try a little
more on the throttle. If there is anything wrong with the engine,
it just a matter of time before it goes anyways, the motor is probably
working harder at low RPM's trying to plane the boat all the time.
Give the boat some gas once she's up then back off the throttle,
the boat should run nice at 3200-3400 rpm,s. A 120hp is not a lot
of power for a 18 footer. Take the boat out solo for a while and
see what it does without extra weight, and experiment. Let us know
how you make out.
Jeff
|
| 111.2 | Some Suggestions | NRADM::WILSON | In the last days of bachelorhood | Mon Aug 15 1988 15:06 | 25 |
|
Has this boat always had this problem, or has it developed as it
got older? As Jeff said, 18 feet is a lot of boat for a 120hp I/O.
Back in '71 engines were rated without any accesories or drives
attached, so even when new it probably only produced 100hp at the
prop. Now figure in lost hp due to wear, and the fact that you're
afraid to take it past 3000 rpm, and you may only have 60-70 hp at
the prop.
A new prop probably would not help unless your present one is damaged.
A speed prop would make it even harder to get on plane, and a power
prop would increase the rpm's, which you stated you are afraid to do.
Try checking all the normal things like timing, make sure the carb
opens all the way at full throttle etc. A four cylinder I/O really
needs to run past 3000 rpm to produce any power, so you may want to
look at whatever it is that makes you afraid to run it that fast. It
could be just a simple valve adjustment.
Another thing is to make sure the hull has not become water-logged
or have water trapped in the bilge. Even with a fiberglass boat this
can add a couple hundred extra pounds.
Rick W.
|
| 111.3 | | PSYCHE::DECAROLIS | GPX User | Mon Aug 15 1988 15:30 | 5 |
|
How about a whale-tail? Anyone know if these things work?
jd/
|
| 111.4 | It was the power trim gauge ... | NRADM::KARL | | Wed Aug 17 1988 18:23 | 1 |
|
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| 111.5 | Power trim gauge (111.4 continued) | NRADM::KARL | | Wed Aug 17 1988 18:26 | 16 |
| Thanks for your advice! I took the boat out yesterday, and it turns
out that the power trim gauge isn't accurate, so that the outdrive isn't
really down all the way when the gauge says it is.
I didn't have any problem planing once the outdrive was down all the
way.
I don't know what caused the gauge to be off - I thought it worked OK
last year. I was able to level off at 2400 RPM. What a difference! It
was great getting the boat up to speed again!
I guess the boat was working so hard at whatever angle the outdrive was
at before, that it sounded like it was really straining, which is one
reason I didn't want to push it.
Thanks again.
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| 111.6 | adjust | TOMCAT::SUTER | Water is meant to ski on! | Thu Aug 18 1988 13:23 | 6 |
|
I believe the adjustment for the trim gauge is a
fairly simply screwdriver job... On the gauge itself...
Rick
|
| 111.7 | WhaleTail/Doelfin | USRCV1::FRASCH | | Fri Aug 26 1988 19:41 | 9 |
| Re .3 "Whale-Tail"
I hear they work great !! One that is supposed to be better is a
unit called "Doelfin" (sp?). A friend of mine has the Doelfin on
a 185 hp Evinrude on a 22' Persuit. It POPS out of the water with
8 people on board. (He runs a Charter) I think they go for about
$80.00.
Don
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