Hello
 

Not sure if I'm doing this right...but here goes.
Just bought a 2000 Shabah 182 with 4.3 L. Boat is really slow out of the hole with a top speed of
about 45 MPH. Is this normal?....Help!!!!!

Re: Hello
 

First...welcome aboard.

Second....what is your WOT (wide open throttle) rpms at top speed and what pitch prop is on your boat?

Third.....when is the last time it had a tune up?

Re: Hello
 

Hey Mikey, thanks for the reply.

Unsure of RPM as Tach is not working, part is on order.
Prop is 21, 14.25 Stainless
Just had the motor timed & idle reset. In addition, my mechanic discovered 2.5 litres of excess
oil in the engine which was of course removed. Obviously, this increased performance, but I still feel the boat is really sluggish and drives heavy.

Any insight or suggestions would be appreciated.

Jeff

Re: Hello
 

2.5l of excess oil? Wow. It may take the motor a bit of running before it cleans up the effects of the excess oil.

The 21" prop will make you a sluggish out of the hole but it should have you running close to 50mph at top end if the prop is in good repair & if the engine is right. I'm curious as to why the tach needed replacement? Or was it something else related to the tach operation? Its pretty rare that a tach fails on its own & usually it's just a corrosion issue either within the tach or within the wiring. If its within the tach it can sometimes be fixed by spinning the cylinder dial on the back a few times then resetting it to '6cyl' once done.

Changing the prop to a 4 blade 20" or a 3 blade 19" will significantly improve your hole shot as will adding a pair of Smart Tabs. The Smart tabs also have the benefit of reducing/eliminating porpoising and low speed wander as well as proving faster planing and being able to run on plane at slower speeds. Do a site search for "Smart Tabs" and you will find all sorts of information on them.

Re: Hello
 

Disclaimer: Far be it from me to contradict MikeyT, as he's certainly far more knowledgeable about Mariah boats than I, but...

I guess depending on expectations, desires, the specific boat, load, etc.

Yesterday we finally got Shazaam! in the water for the first time this season. She has a remanufacturered 4.3L MerCruiser V6, 4 bbl., with Alpha 1 drive and a 23 pitch, 3-blade MerCruiser aluminum prop. Coming out of the no wake zone, into light waves/chop (mostly around one foot or less), I was going to put the throttle all the way down just to see how fast she'd come up on plane. (I'd not been able to do that more than once, last season, because the newly reman'd engine was still in initial break-in. The one time I had done it, I'd had a boat-load of passengers.) Now I didn't slam the thottle down, but I advanced it "with authority." Before I could get it quite to the stop, she was already planed-out! Shazaam! had popped out of the water like a flippin' cork--had leapt as if she'd been fired out of a sling shot--and, before I knew it, was doing over 30 MPH and accelerating. Could've knocked me over with a feather.

Load: Me (192 lbs.), a full tank (30 ga.) of gasoline and maybe... 10-15 lbs. of anchors in the forward port locker?

Jim

Re: Hello
 

Thanks for the tips. I have a 3 blade 19 with the boat and I'll give it a try. Any idea what the stock prop was? Any chance the secondaries on the carb arn't opening up? I'll keep working at it and hope for the best because we really like the boat, but are disappointed with it's performance so far.

Don't hesitate to send along aditional advice

Jeff

Re: Hello
 

Thanks for the insight. My boat definitely doesn't have that kind of hole shot. You say your prop is a 23 pitch....what size is it and do you know what the stock prop for these motors is?

Jeff

Re: Hello
 

14-1/4", if I recall correctly.

I'll find out if I was just imagining it, yesterday, because it seems we've had a Change Of Plans and, instead of going sailing in Abracadabra, we're taking Shazaam! out for a meet-up with friends at a popular swimming/hang-out place on the lake.

Jim

Re: Hello
 

SEMIJim's boat is a rare beast when it comes to props. Most (if not all except Jim :) ) of us run somewhere between a 19" and a 21" pitch and the boats generally came with one of those two props when new. Give the 19" a try first and have a look at the Smart Tabs. Here's the link to Nauticus.

Jim: Do you have Smart tabs on your boat?

Re: Hello
 

I would also suggest calling your local prop shop. Tell him your WOT and engine info, specs of your current prop, and bit about your boat, and he should be able to tell you if it is likely your prop or your engine and what you should expect from your boat.

The prop shop in Austin, TX has a super reputation such that they are busier the heck. Hopefully you will get this figured out and have a good prop shop you can call.

I guess the other obvious question is.. what did your mechanic say about how it ran? He should be able to tell you if all is right or not.

I have a 5.7 on my 202 Shabah so I can't help you on comparison, but my boat is in no way sluggish or heavy. I have a 4 blade powertech prop, but cant remember the pitch.

Good Luck, Dave