180, 3.0 with 2.0 Drive, SeaRay

DEWEY

New Member
Oct 16, 2020
5
USA, East Coast, Fresh Water
Boat Info
180 SeaRay Sport 3.0L 2004, 14.250-19P SSprop
180 Chaparral 4.3L 1998, 1.81R Drive, SS19P prop Sold
Engines
3.0 Mercruiser, Alpha1, 2.00-Drive
3.0L Engine.JPG
Engine Cover.JPG
Flame arrestor.JPG
Front.jpg
Low Emissions.JPG
Rear.jpg
Ive been combing the forums the past couple weeks & decided to make a account.

Owned a 1998 Chaparral with a SS19p prop 13yrs that planed out quick but wouldn't stay on plane at lower speeds. Best mph was about 55 per the gauge on calm water.

Sold the Chaparral & bought the SeaRay as I liked the non carpeted flooring.
I was giving all the service records the previous owners had the boat serviced though the yrs.

When I was checking the engine over it has #6 heat range sparkplugs & what looks to be a 160 thermostat per the gauge.
(Just thought it was interesting since the ford 302HO engine came stock with a hotter #5 sparkplug & like a 190ish thermostat).
I haven't verified the 3.0 timing myself yet.

My 1st test out there was a hesitation issue so I siphoned the fuel tank on the SeaRay & filled with non-ethanol fuel & spray cleaned the carburetor. Hesitation is now gone.

I noticed the 3.0 SeaRay engine feels & sounds weak to plane out even though the boat planes out pretty decent as it doesn't seem to sit that low in the water, it definitely doesn't feel as heavy in the rear compared to the chaparral 4.3 boat.

Ive noticed there is more engine noise on this 3.0 SeaRay with its fiberglass engine capsule & its foam compared to the wood platform that contained the chaparral 4.3 engine but the engine is easier to get to in the SeaRay for service work.
Cruising wise 3000 rpm in the SeaRay is as much as I could stand noise wise, the stock mph gauge was roughly 30.

Idle wise the stock tach shows 1000rpms.

Top speed with full tank & just me aboard was 38-40 mph by GPS vs the stock tach @ 3600 rpm. The stock aluminum prop would note-abruptly/harshly/violently unhook from the water when trimming out for speed, I never had that issue with a SS-prop on the 4.3 boat so Im thinking its because the aluminum prop isnt cupped on its trailing edge.

I was reading about trim tabs on clubsearay & for my boat I see the main benefit is control in choppy water. This 180 searay stays on plane pretty well at low speeds.

Just sorting out my options.
Ive read some here recommend a SS prop on the 3.0 engine & use it.
Ive read some here that dont recommend a SS prop on the 3.0 engine due to the props weight.

Im getting the impression from reading on clubsearay that the 5 blades aren't recommended for small engines.
Looks like MikeyF (last posted 2013) likes the 21P - High 5 on his 3.0.

Of course any holeshot, midrange pull advantage is always a plus & staying hooked up in turns is also.
I don't like how the prop unhooks so abruptly/harshly/violently when trimming out as it leads to less mph.
Concerned about increased noise from engine rpms if reducing prop pitch.


Any incite is welcomed.






.
 
Last edited:
You say the prop "unhooks" when trimmed out... as you trim up, the prop essentially has no more water to push. Trim it back down until it hook up and that's all you got. I don't think swapping the prop will change that.

Best of luck and welcome to CSR!
 
As a update on the 3.0

Did a test run today.
Fuel tank was full (non ethanol 93) as was before.


About a couple weeks ago (post 1)
Used prop - My stock oem 3.0 aluminum prop 14.250" x 21
GPS 38-40 @ 3600 rpms per stock tach (dont recall now but could of been +/- 100 rpm)
Prop unhooks in turns
Prop unhooks abruptly/harshly/violently when trimming out for speed

Today
Used prop - Michigan Wheel, Rapture SS 14.250" x 19 (Part# 033076)
GPS 39-40mph @ 3700 rpms per stock tach (I think I see why some people go to a 17 pitch as the Stainless Steel prop "cupping" reduces engine rpms by 150-300 rpms)
Very minor difference in hole shot
Engine rpms still slow to increase
Better control in turns
Prop DOESNT unhook abruptly/harshly/violently when trimming out for speed aka better control.



(OTHER)
This SS prop was roughly 8lbs heavier than my Mercruiser oem aluminum prop.
This SS prop has a hub with a brass core completely through its prop unlike the Mercruiser oem prop that had maybe half the contact.
(aka hub slip control)
 
Last edited:
I think your tachometer isn’t reading correctly. The noise of the 3.0 is likely normal. I’ve had those motors and they work well but you won’t have quiet cruising and thrilling performance. You should be up to 4800rpm wide open. Make sure the wiring on your tachometer isn’t loose or corroded.
 
my 1995 Sea Ray 175 with 3.0Mercruiser 2.0 reduction does 39mph gps with a few people on board at 4800 rpm. stock prop got a few more mph at 4600rpm. unfortunately I don't know the size, pitch, model of either of them.

I agree, it's worth checking the tachometer.
 
View attachment 93631 View attachment 93632 View attachment 93633 View attachment 93634 View attachment 93635 View attachment 93636 Ive been combing the forums the past couple weeks & decided to make a account.

Owned a 1998 Chaparral with a SS19p prop 13yrs that planed out quick but wouldn't stay on plane at lower speeds. Best mph was about 55 per the gauge on calm water.

Sold the Chaparral & bought the SeaRay as I liked the non carpeted flooring.
I was giving all the service records the previous owners had the boat serviced though the yrs.

When I was checking the engine over it has #6 heat range sparkplugs & what looks to be a 160 thermostat per the gauge.
(Just thought it was interesting since the ford 302HO engine came stock with a hotter #5 sparkplug & like a 190ish thermostat).
I haven't verified the 3.0 timing myself yet.

My 1st test out there was a hesitation issue so I siphoned the fuel tank on the SeaRay & filled with non-ethanol fuel & spray cleaned the carburetor. Hesitation is now gone.

I noticed the 3.0 SeaRay engine feels & sounds weak to plane out even though the boat planes out pretty decent as it doesn't seem to sit that low in the water, it definitely doesn't feel as heavy in the rear compared to the chaparral 4.3 boat.

Ive noticed there is more engine noise on this 3.0 SeaRay with its fiberglass engine capsule & its foam compared to the wood platform that contained the chaparral 4.3 engine but the engine is easier to get to in the SeaRay for service work.
Cruising wise 3000 rpm in the SeaRay is as much as I could stand noise wise, the stock mph gauge was roughly 30.

Idle wise the stock tach shows 1000rpms.

Top speed with full tank & just me aboard was 38-40 mph by GPS vs the stock tach @ 3600 rpm. The stock aluminum prop would note-abruptly/harshly/violently unhook from the water when trimming out for speed, I never had that issue with a SS-prop on the 4.3 boat so Im thinking its because the aluminum prop isnt cupped on its trailing edge.

I was reading about trim tabs on clubsearay & for my boat I see the main benefit is control in choppy water. This 180 searay stays on plane pretty well at low speeds.

Just sorting out my options.
Ive read some here recommend a SS prop on the 3.0 engine & use it.
Ive read some here that dont recommend a SS prop on the 3.0 engine due to the props weight.

Im getting the impression from reading on clubsearay that the 5 blades aren't recommended for small engines.
Looks like MikeyF (last posted 2013) likes the 21P - High 5 on his 3.0.

Of course any holeshot, midrange pull advantage is always a plus & staying hooked up in turns is also.
I don't like how the prop unhooks so abruptly/harshly/violently when trimming out as it leads to less mph.
Concerned about increased noise from engine rpms if reducing prop pitch.


Any incite is welcomed.


.

Had a 1991 sea ray 170 with a 3.0 for many years. You’re performance mentioned seems right on par for a 3.0, although the tach isn’t working. You should hit close to 4800 rpm WOT.

It will be noticeably down on power vs a similar size boat with a 4.3.

I ran Michigan vortex props on mine both 4 blades and 18” for general use and tubes,16” for towing skiers. They also gave better holeshot and stern lift and didn’t blow out like you mention due to reasonable amount of cup. You loose a little top end but if thought was a nice fit for a 3.0 in a 18 ft boat.

You can spend more on a SS prop but you probably don’t have enough hp to really take advantage of it. The vortex props for like $150 are a great value.

I found my 3.0 to be fairly loud as well especially at a reasonably quick cruising speed. Not sure why just typical of the engine. They also tend to idle a tad rough and be a little clacky. What a 3.0 is good at is being economical, durable, and easy to maintain. If you are getting 38-40 mph you’re doing about as well as you can. If the noise is too much look at beefing up the sound deadening in the cowling. I replaced mine with some materials from a company called Soundproof Cow. They were helpful in materials selection, like anything else you can spend a bunch and get great results...

I do miss putting $60 gas in , boating all weekend and still having a qtr tank left... my newer boat is a 2004 200 sport with a 5.0 so more people, more engine= more gas.

thermostat and plugs you mention are fine. Mine typically had the two middle cylinders with blacker plugs than the end two. Not sure why I had the boat for 20 years, beat the hell out of it skiing and tubing with the kids.
 
Cool

In general (AirSpeed)
the longer runners of a intake will tend to make a cylinder run leaner.
&
the shorter runners of a intake will tend to make a cylinder run richer.
Just thinking outloud, stepping to a hotter plug on those 2 cylinders may clean it up.

I was looking at some of those rectangle digital tachs to get a idea on the rpms but likely be June before taking the boat back out.

Is this the prop you were referring to?
Michigan Vortex 4-Blade Prop, Exchangeable Hub / Aluminum, 14.5 dia x 18, RH
 
Yes that the prop, also ran a 16” for skiing
 

Forum statistics

Threads
112,945
Messages
1,422,746
Members
60,928
Latest member
rkaleda
Back
Top