Logo
FULL SITE MENU

Just bought a mercruiser 470 have a few questions

Sorry jadilla, meant no harm! Just trying to give you an idea of what you could be up against. I would do a full compression test on any engine before I were to buy it. Just sayin, before you go and dump a wheel barrow of money into the thing. Listen to it run or better yet run the boat it is in if possible. You were asking about the location of the lowest point of the cooling system. That is at the 7:00 position looking at the front of engine and it is as kghost said at the bottom. Make sure when you put the brass plug back in that you start it by hand so as not to strip aluminum threads as kghost suggested. Take your time and you should be ok. That is the best place to drain it because any rust,silt,debris type material floating in the block tends to hang out at the bottom of circulator pump housing and that is where the cam seals are located so I like to keep coolant extra clean and drain every season. In my case, I got the engine out of another boat. I did not pay for it but it was pretty much junk before rebuilding. Number one and four cylinders were locked solid with rust from leaking riser or missing flapper. The exaust water shutter is located on the 1987-89 version 470 exaust pipe, at the top of the last section that connects to the transom. Not sure about the earlier versions but has to be in the exaust somewhere. Hey dockside thanks for the info. on the stator tool. When I reinstalled the stator, I did not have the right tools and was able to get it back on but it was not easy. I was afraid of banging too much with a block of wood because of the aluminum block, seals, etc. I think I had to buy a longer mounting stud to help start pulling as I tapped with the block of wood. Primitive method I guess but it worked. My brother bought a $3500 Snap on puller set with cabinet and all about 6 months later. Who would figure? Ricardo, Mercs original oem equipment on this motor was questionable at best with regard to the known issues. I would love to install an AFR aluminum head on that puppy with scorpion roller rockers and a custom water pipe machine fitted to the front of head for the cooling system. I don't think you can jack up the compression to much because the head bolts go into aluminum threads in an aluminum block. It sure as hell would get rid of the bastardized step child notion with respect to the cast iron head on an aluminum block. I think there were guys using the 470's in some kind of sprint cars and from what I have read were able to get them up to 250 horse. (of course with a bunch of expensive modifications) I think the the compression ratio is 8.8 to 1 on a stock engine. I may just do the aluminum head if things get better with the economy but for now, will run it the way it is! later guys, Tom
 
Last edited:
1973 Browning Marine said:
Sorry jadilla, meant no harm! Just trying to give you an idea of what you could be up against. I would do a full compression test on any engine before I were to buy it. Just sayin, before you go and dump a wheel barrow of money into the thing. Listen to it run or better yet run the boat it is in if possible. You were asking about the location of the lowest point of the cooling system. That is at the 7:00 position looking at the front of engine and it is as kghost said at the bottom. Make sure when you put the brass plug back in that you start it by hand so as not to strip aluminum threads as kghost suggested. Take your time and you should be ok. That is the best place to drain it because any rust,silt,debris type material floating in the block tends to hang out at the bottom of circulator pump housing and that is where the cam seals are located so I like to keep coolant extra clean and drain every season. In my case, I got the engine out of another boat. I did not pay for it but it was pretty much junk before rebuilding. Number one and four cylinders were locked solid with rust from leaking riser or missing flapper. The exaust water shutter is located on the 1987-89 version 470 exaust pipe, at the top of the last section that connects to the transom. Not sure about the earlier versions but has to be in the exaust somewhere. Hey dockside thanks for the info. on the stator tool. When I reinstalled the stator, I did not have the right tools and was able to get it back on but it was not easy. I was afraid of banging too much with a block of wood because of the aluminum block, seals, etc. I think I had to buy a longer mounting stud to help start pulling as I tapped with the block of wood. Primitive method I guess but it worked. My brother bought a $3500 Snap on puller set with cabinet and all about 6 months later. Who would figure? Ricardo, Mercs original oem equipment on this motor was questionable at best with regard to the known issues. I would love to install an AFR aluminum head on that puppy with scorpion roller rockers and a custom water pipe machine fitted to the front of head for the cooling system. I don't think you can jack up the compression to much because the head bolts go into aluminum threads in an aluminum block. It sure as hell would get rid of the bastardized step child notion with respect to the cast iron head on an aluminum block. I think there were guys using the 470's in some kind of sprint cars and from what I have read were able to get them up to 250 horse. (of course with a bunch of expensive modifications) I think the the compression ratio is 8.8 to 1 on a stock engine. I may just do the aluminum head if things get better with the economy but for now, will run it the way it is! later guys, Tom
Click to expand...

No need to apologize man.... thanks for the help if anything!!! I'm very happy with the engine so far. I'm going to be extremely easy on it so hopefully with adequate maintenance and babying her, she should last a while.
 
I only wish you the best jadilla, that is why I pretty much ate your ears off. Just trying to give you a fighting chance. If the engine is indeed strong internally. (rings,bearings etc.) then you can run the engine like you would any engine. But the key is making sure all maintenance is performed and the engine is running properly as intended. You don't have to be shy with the thing. Actually, it is good to blow her out once in awhile just to make sure the engine can attain wot and is getting full power. (that's all) Good oil, fuel, timing, plugs, wires etc. can be a big factor in performance and fuel consumption.
 
Timing... good. New plugs, in process of oil change, checking water impeller. Flushed coolant syster, run non ethanol 93 octane with sea foam added. And I'm not gonna lie. Seems extraordinarily powerful, and clean for what it is. Just can't wait to get a propeller, and really try her out.
 
If buying a new prop for this make sure you monitor your max, wide open throttle rpm's with the outdrive trimmed up just before cavitation occurres, ~1/2 tank of fuel and only you in the boat.

This is how to select prop pitch to achive specified max RPM'S. I also would say that if the max rpm's specified for that motor is 4200-4600 I would suggest to keep it the lower vs higher rpm range. Just a suggestion.

Incase you did not know prop pitch is what alters max rpms. Kinda like changing rear end gears in a car.........

Lower pitch = higher max rpms quicker but lower top end speed. Example: 15 pitch would be a lower pitch. better hole shot like for pulling skiers.

Higher pitch = lower max rpms but higher top end speed. Example: 21 pitch would be a higher pitch. longer to get on plane but higher top speed.

There are no perfect set ups and sacrifices are made to accomidate personal usage but in general prop pitch is selected to achive max RPM's (Engine specified rpm's)


If this were a V6 or V8 then 4800 -5000 would be OK, but it is NOT. Over revving this motor will lead to a short life span........
 
Last edited:
Got to start somewhere and "most" boat biulders (under 24 ft pleasure craft) try to use 19 pitch as the correct one for max operation. Not always is best but typical and works......

My boat when new and up to the plastic hub props was a 19, now due to the changes with the plastic hub prop i went to a 21 to achive the same max rpms ans speed. With the plastic hub prop I gained almost 300 rpms but no real mph increase.......put me close to if not over 5000 rpms.....

Also a rebiult is significantly different than a brand new. Brand new have a nice cupped edge, Most rebiult do not have a cup or at least not as large as a new one, so it will act similar to a lower pitch prop and cause a slight higher rpms...........Just be aware of this if using a rebiult to choose the correct pitch........
 
HEY GUYS CAN SOME ONE HELP ME ON MY PROBLEM I GOT A 1982 MERCRUISER 470 THAT RUN'S SO GREAT THE PROBLEM I'AM HAVING I HAVE A BACK FEED TO MY COIL , MY ENGINE WON'T SHUT DOWN , I PULLED THE WIRES OFF THE key ignition switch THE ENGING STAY RUNNING I PULLED THE PLUG OUT FROM THE MAIN DASH BOARD STILL NOTHING REMOVE THE PLUG BY THE MOTOR STILL NOTHING COULD IT BE THE STARTER OR THE solenoid ON THE ENGINE. I GOT POWER GOING TO MY COIL AND THE MOTOR WON'T SHUT DOWN ITS SOMETHING I'AM MISSING I CAN'T GET IT ITS DRIVING ME CRAZY PLEASE CAN SOMEONE HELP ME PS THIS MOTOR HAS voltS regulator COULD THAT BE MY PROBLEM THANKS RICH
 
does any one know where i can get parts for the 470 motor? new or used i need the front cover for the impeller it's part # 1 Or 15 depends on the drawlings
 
bluestreak said:
does any one know where i can get parts for the 470 motor? new or used i need the front cover for the impeller it's part # 1 Or 15 depends on the drawlings
Click to expand...

Ayuh,... Start a thread of yer own,....

This 1 died over a year ago, 'n nobody will find yer question down here on page 2....
 
I just joined the site and cannot figure out how to start my own thread so being similar in nature to this one, hope its ok to ask for help here ? 5 years ago I bought a 84 Galaxy with a Mercruiser 470 and the Alpha 4.3 outdrive. Had pretty good luck with it 3 years in the rough waters of Lake Erie. Last time out lost my prop had to be towed in. Last year didn't get it out at all was gonna sell it but too late in year to get a buyer. Now we moved to Cave Run Lake and I wanna get in running, but having issues. Starter kicks out but won't turn motor over. Reading some forums I took out a plug and attempted to manually rotate motor with a rachet. Seemed loose the bolt it kept turning getting tighter but not stopping to engage the crank. Got worried was gonna snap bolt off I quit and loosened it back up. Now I'm aware there is a stator behind that crank pulley that's suppose to be tightened a certain amount of lbs. Does anyone know what that is ? I guess Ill rent a gear puller from autozone and back this stator back off the block. Hope I didn't ruin it but nothing sounded like anything cracked. Ill pull the starter today as well to see if its shot. It kicks out just doesn't spin to attempt to start it. Thanks in advance for any help.
 
Hey Bondo after I posted my dilema I seen your response above. How do you start your own thread ? Just need a bit of info on my 470. Thanks in advance.
 
Yes.... this thread was started a year ago.

At the top of the Merc forum, you'll see a " + Post new Thread " hyperlink.
Click on the link, and you'll be re-directed.


.
 
Last edited:
Back
Top