Prop suggestions Cobalt 190

[PlentyofChaos]

Any prop suggestions from experience for a 2000 Cobalt 190, Mercruiser 4.3 EFI sterndrive, Alpha 1/gen2?

Right now it has a stainless Vengeance prop, I don’t know the specs. Full throttle is 5000 rpm getting about 43 mph. Seems like a bit high on the rpm’s, and I’d like to get more top end speed.
Thanks all!

[Kate]

"I don’t know the specs."

You need to know them. Rule of thumb is: Higher pitch equals more top end/worse hole shot. Here's what I've done: Sea trialed two props -- one +2 pitch, the other +4. I chose based on actual performance.

"Seems like a bit high on the rpm’s . . ."

5k is about right. Consult the owner's manual, available at the Cobalt website. Cruise should be about 80% of WOT rpm and mph.

[jhnmdahl]

EDIT - this post assumed the non-EFI engine; see below posts for EFI engine options

Here's a recommended propeller chart for your boat. Note also that putting on a propeller that won't let you approach the engine's top RPM generally won't make you go faster, so once you know your outdrive ratio (assume it's 1.81, use a 13 3/4 x 21 prop, part number 48-832832A45 or equivalent?) I'd at least start pretty close to the chart below.

Looks like Mercury currently has several 13.6-13.8" props that might fit the bill - perhaps something like https://www.mercurymarine.com/us/en/pro ... #8M0151243

Note some dealers will let you try a few props and keep one, assuming they're brought back in new condition fairly promptly.

Mdl Mfgr Engine Drive Fuel system std. ratio Opt php Prop Dscpt Mfg. part #
190 Merc 3.0L ALpha 2 BBL 2 2.4 140 13.5 x 23 48-83283A45
190 Merc 4.3L ALpha 2 BBL 1.81 2 190 13 3/4 x 21 48-832832A45
190 Merc 4.3L Bravo 3 2 BBL 2.43 NA 190
190 Merc 4.3LH ALpha 4 BBL 1.62 1.81 205 13 3/4 x 21 48-832832A45
190 Merc 4.3LH Bravo 3 4 BBL 2.2 2.43 205 26's 48-823667A6/68A6
190 Merc 4.3L EFI ALpha Throttle-Body 1.62 1.81 210 14.5 x 19 48-832830A45
190 Merc 4.3L EFI Bravo 3 Throttle-Body 2.2 2.43 210
190 Merc 5.0L ALpha 2 BBL 1.62 1.81 220 13 3/4 x 21 48-832832A45
190 Merc 5.0L Bravo 1 2 BBL 1.65 NA 220 14 3/4 x 21 48-13702A45
190 Merc 5.0L Bravo 3 2 BBL 2.20 2.43 220
190 Merc 5.0L EFI ALpha Throttle-Body 1.47 1.62 240 14.5 x 19 48-832830A45
190 Merc 5.0L EFI Bravo 1 Throttle-Body 1.65 NA 240 14 3/4 x 21 48-13702A45
190 Merc 5.0L EFI Bravo 3 Throttle-Body 2.2 2.43 240 26's 48-823667A6/68-A6
190 Volvo 4.3GL SX 2 BBL 1.79 1.89 190 14 1/4 x 21 RH 3850302-5
190 Volvo 4.3GL DP 2 BBL 2.32 NA 190 F8 3851498-0
190 Volvo 4.3GS SX 4 BBL 1.79 1.89 205 14 1/4 x 21 RH 3850302-5
190 Volvo 4.3GS DP 4 BBL 2.32 NA 205 F5 3851495-6
190 Volvo 4.3Gi SX Throttle-Body 1.79 1.89 205 14 1/4 x 21 RH 3850302-5
190 Volvo 4.3Gi DP Throttle-Body 2.32 NA 205 F7 3851497-2
190 Volvo 5.0GL SX 2 BBL 1.6 1.79 220 14 1/4 x 21 RH 3850302-5
190 Volvo 5.0GL DP 2 BBL 1.95 2.32 220 F6 3851496-4
190 Volvo 5.0Gi SX Throttle-Body 1.6 1.79 250 14 1/4 x 21 RH 3850302-5
190 Volvo 5.0Gi DP Throttle-Body 1.95 2.32 250 F6 3851496-4

[PlentyofChaos]

A bit too technical for me. But, I have the EFI engine. Doesn’t this engine specify the 14.5 X 19 in this chart, Alpha drive?
I don’t know what is on there currently. Tried to look for markings but not sure where to look. And the boat being in the water presents a challenge.
But appreciate the advice!

[Kate]

"not sure where to look."

The info should be stamped on the hub, with the last number the pitch.

BTW, assuming it's in decent condition, that Vengeance is a quality prop.

[PlentyofChaos]

Ok, cool. This will need to wait a couple weeks until I pull it out, but I will check for the job stamp.

[PlentyofChaos]

A bit more research on the engine suggests a WOT range of 4400 to 4800 with max hp output at 4600 rpm. This leads me to speculate that running WOT at 5000 rpm is too much and maybe there isn’t enough prop.
Let me reach out to some prop shops as well.

[jhnmdahl]

A bit too technical for me. But, I have the EFI engine. Doesn’t this engine specify the 14.5 X 19 in this chart, Alpha drive?
I don’t know what is on there currently. Tried to look for markings but not sure where to look. And the boat being in the water presents a challenge.
But appreciate the advice!

Yep, you're right - a bit more power out of that one, so you need a different prop. There's a good chance a 19" pitch will be the right one for you (i.e. the prop goes forward 19" in the water in one full revolution with one turn of the propeller). Check out one of:

https://www.mercurymarine.com/us/en/pro ... #8M0151239

or

https://www.mercurymarine.com/us/en/pro ... #8M0151321

biggest difference is that the second one is a four blade, which will pull harder (think towing a skier or getting on plane faster), but may not have quite the fuel economy at top speed as the three blade propeller.

Other things in the table are outdrive ratio, which is like a transmission ratio between the engine and the propeller, and the diameter of the propeller (13" or 14"), where bigger diameter propellers can catch more water and provide more pull for a bigger or heavier boat but have more drag at high speed and need a more powerful engine to drive.

A good prop shop should help you confirm your choices, and be willing to swap propellers if things don't work out as you'd hoped.

John

[PlentyofChaos]

Any prop shop recommendations?

[jhnmdahl]

Well, I like PropMD, but they're in my home town. Looking online a bit, I wonder if these guys are closer to you:

https://www.philaboat.com/services/8405 ... rop-repair

Many members have come to know a local guy who is a prop expert and will help them find the right thing, such as viewtopic.php?p=46563 but you might have to ask around your area a bit (see who the Cobalt dealer recommends?) to see who is the best fit for you.

[PlentyofChaos]

Awesome!

[PlentyofChaos]

Prop is a 17P. Not getting it done.
What do you think about the Michigan Wheel XHS? The guy there recommended 19P for that prop.

[Kate]

Michigan Wheel XHS

Factor in the cost of a hub kit.

[jhnmdahl]

Looks like Michigan Wheel's Apollo XHS comes in a 19" and either a regular or large diameter 3-blade (unspecified diameter measurements on their site) or a 4-blade.

https://www.miwheel.com/propellers/outb ... -series-a/

A quick look at a vendors web page shows that the 3-blade 19" is available in 13 1/8 or 14 1/8, and 15 1/4x19. I suspect the 14 1/8 will be the right one, and is pretty close to Cobalt's table and Mercury's recommendations. Makes sense to gather all your specs and info, and confirm with either Michigan Wheel or the prop shop before ordering though.

https://www.boatpropellerwarehouse.com/ ... s-19_pitch

Thanks for keeping us posted.

[PlentyofChaos]

That’s my direction. Thanks!