96 70HP Evinrude-Impeller replacement and general engine comments

[jimogeek]

Hi all.<br /><br />I have a 20' Lowe pontoon with a 70HP Evinrude. It's been a great engine so far, and I just finished winterizing it last weekend. I have two questions:<br /><br />1. The procudure for replacing the impeller looks to be pretty hairy. Can someone give me a rough estimate on time it will take (I'm a pretty good wrench) to yank the lower unit and do this job? Any general outline of what I'll be doing? What pitfalls should I look for? Advice?<br /><br />2. How do people like this engine? It's been great so far. I ran it a couple of times a week over the summer with no problems. It seems to idle a bit high at startup (around 1200-1300 RPMs), and only gets to 5,000 RPM at WOT witha 14x13 prop though... <br /><br />Thanks for the advice!

 

[jimogeek]

Re: 96 70HP Evinrude-Impeller replacement and general engine comments

Duh! It's a '96 Evinrude. Don't have the model number handy.

 

[rickdb1boat]

Re: 96 70HP Evinrude-Impeller replacement and general engine comments

I've got a toon with a 91' 70HP on it and I love the motor. Never had a problem in 12 Years. One of the best motors they made! Regular maintenence has helped me out. The lower unit has no suprises. Pretty straight for if you follow the manual. Pretty much remove the bolts and disconnect the shiftshaft and drop her down. Don't forget the bolt on the trim tab. Has to be removed to drop LU. Common mistake not removing it. I have a factory Manual that is perfect for things like this. It only covers 60-70 HP motors of my year. Drop the idle down to 800 RPM's in gear and moving on the water, using the idle adjusting screw. Get yourself a 14 X 11 prop to get the RPM's up. These motors like to run toward the high end of the RPM band. I run a 14 X 11(Just Changed from a 13" pitch at 5400 RPM's) and I run at 5800 RPM's now. What a difference in handleing and a 3 MPH increase in speed. I can make sharp turns now without slowing down much at all and it shoots out of the hole so much better. Feels like a different boat! As for yours, 5000 RPM's will put a large burden on your engine and reduce it's life, not to mention performance reduction. OMC has come out with a prop made for pontoons. It's tripple cupped and available in a 14 X 11 pitch. It's stainless steel and costs about $400.00. Dealer has to order it, but it is supposed to really make your toon get up and go. But for now, an alumnimum will do fine. In the spring, I'm gonna get one of those though!! Happy Boating Next Spring!<br /><br />PS-I see you are also from St. Louis. Where do you boat? My last run this year was at Mark Twain. Used to go to the ozarks until it got too rough. Now go to Tablerock for extended trips. Come on spring! <br /><br />Also, what top speed are you getting out of your set-up?? Always like to compare to see if I'm in the neighborhood!

 

[DJ]

Re: 96 70HP Evinrude-Impeller replacement and general engine comments

jimogeek,<br /><br />Rick is right on regarding the advice. Get a manual. Look here: <br /> http://www.outboardrepairs.com/manuals/ <br /><br />He is also right about the prop.

 

[ob]

Re: 96 70HP Evinrude-Impeller replacement and general engine comments

jimogeek,I too own a 96' 70 hp Rude.Whether you perform the work yourself or have it done ,be apprised that there are a few TSB's on the cooling system that need to be followed.The OMC/BMC waterpump replacement kit changes from a three flute to a 6 flute impeller.(instructions are in the waterpump kit box.Also the T/stat uses a different spring for the bypass feature and a different cover plate.The tell/tale restrictor is done away with and utilizes a grommet through the lower engine pan in its place using the existing hose that exits the top of the block.What you end up with is a larger stream and without the restrictor the cooling system won't have excessive back pressure.<br /><br />You mention that the engine seems to run a bit high rpm on startup.Does that mean that the rpms after engine warms for a bit drop down to near 900 or so.If that's the case be aware that your engine is equipped with a quickstart feature that holds engine rpms up on cold startup for usually several seconds and then should drop back.If it's not working properly you may consider the possibility that the temp sensor is in need of replacement as that is where the quickstart gets its thermo signal.Good luck.<br /><br />Also ,Rick gives good advice as to the recommended WOT engine rpm.Follow it and you'll enjoy many years of trouble free operation.

 

[jimogeek]

Re: 96 70HP Evinrude-Impeller replacement and general engine comments

Thanks all for your help. I'm very gratefull for your advice! <br /><br />OB-The 'rude starts up at around 1200 rpm, and drops down to around 900 after it's warmed up in a couple of minutes. Thanks for the heads up on the advisories, I'll be sure to use them when I get the kit. Which temp sensor were you talking about? <br />I'll be passing through Corpus in a few days for our annual holiday visit to see my wife's people, I'll be sure to wave!<br /><br />djohns-I've got the manual, but I wish I'd have seen that site before I bought it! They're much cheaper!<br /><br />Rick-I think I'll try the prop you recommended, and see what results that gives me. I think 5K is way too low, and I remember that at the beginning of the season I was getting around 5300, but that was before my prop went bad and I got another replacment (14x13-OMC replacement"). I don't know what my top speed is, I'll get a handheld GPS out there someday to measure.<br />I live out in Holiday Shores, just north of Edwardsville, IL. I'm fortunate enough to have a dock in my backyard, and the boat stays in the water from about April 'till November (with a couple of trips out of the water for maintanance and cleaning!). My kids get tired of the boat! Whats wrong with this generation! Oh well. I love the thing, and it pulls them very well on tubes, although I'd like to get something we could ski off on day...<br /><br />Thanks again for all of the great advice!

 

[rickdb1boat]

Re: 96 70HP Evinrude-Impeller replacement and general engine comments

jimogeek <br /><br />OB is right on about all that he said. Gives excellent advice! Forgot the later model had Quickstart. The sensor he is talking about is the temp sender on the back of the head.It screws into the block and has a tan wire coming from it. It's the same one that warns you of an overheat problem. Wish I had that dock set-up in my backyard! I'd be out every day, if I could. Anyway, definitly go to the 11" pitch prop, cause even 5300 is too low with a good prop. I'm sure you will be real happy with the results, not to mention helping your motor live a long and reliable life. Happy Boating in the spring!

 

[ob]

Re: 96 70HP Evinrude-Impeller replacement and general engine comments

jimogeek,Depending on the water inlet temps you guys in St Louis are experiencing this time of year ,it sounds like the temp sensor is doing its job.Sensor is where Rick mentions ,just left of the T/stat cover with a tan/blue stripe wire and a white/black stripe wire exiting.If you ever suspect any problems with it you'll at least know where its at.<br /><br />On a lighter note: Talk about a small world!!