Merc. 350 motor weight issue...

[marioc]

So, I'm contemplating with the idea of re-powering my 21 foot CheckMate with a Merc. 350.

It's easier to work with, it's more reliable, and parts are readily available compared to my current Merc. 470.

So, my question to those more experienced than me is this: Can I compensate for the 350 lb+ additional weight (compared to my 470) by using trim of the motor and/or trim tabs/stabilizers? Or is there a better way to compensate?

Most of what I've read is everyone suggesting to go to the 3.0 motor. This would be dropping 40-60 hp from what I have now(less torque too)!

I feel like my 470 is leaving me little or no options...

Thank you...

 

[stonyloam]

Re: Merc. 350 motor weight issue...

I think it would be fine with that size boat, trim tabs should be able to compensate. You will have to change the outdrive gear ratio to a 1.5, especially if you have a 1.98 now.

 

[marioc]

Re: Merc. 350 motor weight issue...

Hi stony,

Ok, I so much want to keep the 470! I'll have to weight the plus/minus balance sheet...

I guess if I do get a rebuilt one, as we spoke previously, I would need a lower ratio outdrive also.
Thanks for your input... I'll do the tests you mentioned to see where exactly the motor stands.

Have a great weekend! Any updates on your 470? How's she doing?

Mario

 

[marioc]

Re: Merc. 350 motor weight issue...

Stony...forgot to ask you. Where do you get parts for your 470?

 

[stonyloam]

Re: Merc. 350 motor weight issue...

Stony...forgot to ask you. Where do you get parts for your 470?

e-bay for the NLA stuff.

 

[marioc]

Re: Merc. 350 motor weight issue...

OK...Thanks!

 

[stonyloam]

Re: Merc. 350 motor weight issue...

I would need a lower ratio outdrive also.

Maybe not. You could very well be close enough to compensate with a prop change. I run a 15(diameter)/19(pitch). If you go up to the prop forum and tell them what you have they should be able to help you out.

 

[Bondo]

Re: Merc. 350 motor weight issue...

So, I'm contemplating with the idea of re-powering my 21 foot CheckMate with a Merc. 350.

It's easier to work with, it's more reliable, and parts are readily available compared to my current Merc. 470.

So, my question to those more experienced than me is this: Can I compensate for the 350 lb+ additional weight (compared to my 470) by using trim of the motor and/or trim tabs/stabilizers? Or is there a better way to compensate?

Most of what I've read is everyone suggesting to go to the 3.0 motor. This would be dropping 40-60 hp from what I have now(less torque too)!

I feel like my 470 is leaving me little or no options...

Thank you...

Ayuh,... A 21' boat can handle the weight of the 350, 'n the added horsepower will more than make up any handling issues...
Provided the hull doesn't already have handling issues...

If yer that concern with the weight thing,...
Slap in a 4.3l, it'll run with the drive ratio of the 470, 'n saves abit over 100lbs...

The 4.3l is a sweet little motor, that's under appreciated...
With a 4bbl. carb, or Efi, she'll really haul the freight...

 

[marioc]

Re: Merc. 350 motor weight issue...

Bond-o,

I'll have to consider your 4.3 option...I'll sleep on it. Or, maybe see if I can put it on Santa's list! LOL

I do understand there's going to be some fabricating of the stern... or, actually I guess just the engine mount placement via adding a stringer, etc...

Anyway, thanks for something for me to chew on...

Oh', the 4.3 with 4 bbl, about what kind of horserpower are we talking about?

M

 

[Bondo]

Re: Merc. 350 motor weight issue...

Oh', the 4.3 with 4 bbl, about what kind of horserpower are we talking about?

Ayuh,... From 'bout 205hp, to 230hp, dependin' on whether ya spring for the Vortec heads...

Crankshaft horsepower...

Btw,... Ya gotta do the new motor bed, 'n motor box, regardless which way ya swap...