mercruiser 470 replacement?

S

surchin

Member
Well, it appears I may have terminal problem on my 470. it was running fine over july 4, but last weekend It would not crank on starting and we pulled the plugs, a little rusty and the flywheel will not spin with a wrench on it.

I trust my boat shop and they are going to pull the drive to see if its the drive or the motor that is locked up. I am thinking worst case and they are recommending a "bobtail" replacement with a 3.0 L motor ?

Any one done this? $5200 is a quote for the motor. plus labor

Any experience here please ?

Thanks
Scott
santa barbara, CA
 
I'd buy a used 4.3 n swap it in way before I'd pay 5 k to swap in less hp.

Heck for 5k or less you could buy a whole boat ready to go.

Just my $.02 tho.
 
Yep for the money I could def get a used boat. This one works well for me and a new motor is very attractive over another used boat and used motor.

I don't know. Just looking for options.
 
Think of how your boat has previously performed at 2/3-3/4 throttle and figure that for your future full throttle....
As I said I wouldn't go new BUT I can see how you could easily be in a different boat (ha) than me.... I would definately consider more hp than the 3.0.... Heck you could even swap in a 260 if you wanted.... Before dropping that much money in tho make SURE the transom, and stringers are rock solid by drilling some exploratory holes and examining the shavings...
Look over everything else too.
5k and you are 'like new' may be attractive but add another 5k to rebuild the hull and another 2k for a drive and maybe it gets less attractive... OR maybe it still sounds good to ya, I dunno... ;-)
 
$5200+ labor will get close to $7K REAL quick if you aren't careful. And like posted above, it will be a BIG step down in power. Your 470 is probably a 170-185HP VS the 3.0L at 130 or 135HP. So the 3.0L will have at wide open what your current engine has at cruise. Personnaly I would have the hull and stringers checked THOROUGHLY before I would drop another dime in it. If the hull checks out, or only needs minor repairs, I would reccomend shopping around as brand new 3.0l's can be had for a good bot less than $5200 which I believe is full list price. But I would strongly suggest either rpeowering with a 4.3L for simliar performance, or getting a rebuilt 3.7L for it.

ebasicpower has a 3.7L long block for $2395.99
http://bpi.ebasicpower.com/pc/EFMME224LA/REMAN224

And michiganmotorz has a decent rep from what I have heard, and has one for $2899, or a brand new 3.0L complete bobtail for an ALPHA outdrive for $4769
http://www.michiganmotorz.com/37l470-inline-marine-engine-197689-p-628.html
http://www.michiganmotorz.com/mercruiser-complete-engine-package-p-303.html
 
yep, the ocean out here does not allow me to go full throttle however i do a lot of diving and with a couple guys there is a lot of weight, but I'm still 3/4 throttle ish.
and yes I'm looking at a realistic 8-10,000 for this i bet. 5200 for motor was just a quick look up at the boat shop to get an idea.

MY hull is probably not as strong as I think it is, there are no obvious soft spots and the environment here is not moist to creep into wood, and some serious checking is def a first, drilling holes sounds painful but its probably the best way to look at a core.

Thanks boys, I'm open to any more links on all the motor options here, i will check them out. I still may get lucky and it is a bad drive in which case a new SEI drive is my plan. although a new motor and drive is in my dreams.

:nice:
 
what is advantage of a "bobtail" verses a complete motor? 4700 on sale complete is good. would i need to replace mount locations though? i have rebuilt the engine mount stringers a few years ago.

I do not think a new long block that is bare is a good option, all the working parts that attach from my old motor are pretty much 1978 orig or ebayed and the labor costs to remove and rebuild it would be more than a new motor. I do not have knowledge time or space to do it so I'm paying a shop the labor $100 hr. i can't see putting a 30 year old parts, starter, on a new motor as a good option.
 
Last edited:
RED FLAG!!!!
"Rebuilt engine mount stringers"
To do that is a full on tear down
Remove the cap, replace stringers (full length of boat) replace floor....
If you had stringer problems and did any less than that you can forget the motor and start boat shopping.
 
alright smoke yes def some orange flags flying out here, i just know what i have had to do to this old motor when i got this boat on the cheap and i would like to avoid going through that again trying to buy another old boat cheap.

where so you find an old boat in good condition anyway.

i don't know, i guess i will just use my kayak more.
:beer:
 
Ur talkin about spending 10k.... That's not cheap...
10k plus whatever you can get out of your current boat should net you a decent water ready boat.
 
Surchin ...I also run a 78 470 that fortunately runs great. Recently picked up a 3.7LX 190hp fresh water low time engine for spare for 300 bucks...just sayin. If your are not in a hurry they are out there.
 
tw ya i guess thats another way to go - just keep shopping for one but man id hate to go through all that and buy a dog. There is nothing in my area and the pics i have seen of these do not seem worth the effort to purchase and ship one but i am open to any leads if you have any from your effort to get one.

Has anyone actually run a 3.0 and is it actually too little HP to push the boat?
 
A buddy of mine had one in a 17' bow rider .... It did great but that boat had less dead rise and less weight... It could plane a v20 but it would be a dog... Especially loaded heavy in big water.
 
smokeonthewater said:
A buddy of mine had one in a 17' bow rider .... It did great but that boat had less dead rise and less weight... It could plane a v20 but it would be a dog... Especially loaded heavy in big water.
Click to expand...

ok i do load heavy and we do have nasty late afternoon conditions that i try to avoid.

just checking ebay here I see one for 2000+ just seems risky buying used motor i don't know how you reduce that risk.

just gotta wait to see the outcome from boat shop, not get ahead of myself.
 
If you do need an engine, heres al ittle reading for you regarding the 3.7L MERCRUISER engine. As to has anybody done one, I've only seen a handful of V-20's with one swapped in, and I believe tehy all said they were pretty underpowered, and only really suitable for calm waters. Your dropping back in power, and staying close to the same weight. The closest engine in power output to the 470 is the current 4.3L V6 which is the way most go for repowers when they give up on the 3.7L engine.

https://www.perfprotech.com/blog/tech-articles/mercruiser-470-replacement
 
THEFERMANATOR said:
If you do need an engine, heres al ittle reading for you regarding the 3.7L MERCRUISER engine. As to has anybody done one, I've only seen a handful of V-20's with one swapped in, and I believe tehy all said they were pretty underpowered, and only really suitable for calm waters. Your dropping back in power, and staying close to the same weight. The closest engine in power output to the 470 is the current 4.3L V6 which is the way most go for repowers when they give up on the 3.7L engine.

https://www.perfprotech.com/blog/tech-articles/mercruiser-470-replacement
Click to expand...

yup i have read that one a few times over the years ha, i think I'm at that point now though just a feeling...still have hope though, wait for he doctors orders next week.
 
Good news from boat shop. I had a bad out drive. Motor is ok. Ordering a new SEI out drive and keep her going
Thanks for advice
Until next time .....
Scott
 
Update, SEI outdrive ordered and installed and it works great 1250$ parts plus labor. Really glad to have the boat back up for rest of summer!
 
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