Thread subject: Whaler Central - Boston Whaler Boat Information and Photos :: Johnson 70 Water Pump

Posted by Mark Sr on 11/23/09 - 11:43 AM
#1

I was out on the water yesterday and noticed that one of my Johnsons, J70TLECB, had about half the flow of the other motor coming from the waterpump indicator stream. I kept a close eye on it as we motored a long no wake zone. I looked back once and noticed the stream had quit. As I reached for the key to shut it down, I heard the warning horn come on for a split second.

This motor had been producing a bit more smoke than the other the previous trip during no-wake motoring, but that went away after we got up to speed as well as later when we began to troll. It also had consumed more oil than the other motor. I had added some synthetic-blend, 2 cycle "marine" oil to that side's oil tank during the last trip in the boat.

We had a big storm just before the previous trip which left quite a bit of trash in the water. Also, my water inlet holes (where the earmuffs go) are missing some of the plastic screen material. I speculate I might have sucked up some pine straw or something.

Should I just go ahead and replace both motors' water pumps as I do not know when they were last replaced? If so, what other items shall I address while I am going for the pumps? I had planned on doing the pumps after Striper season anyway in January when I put the boat away until March/April.

Thanks,

Posted by MW on 11/23/09 - 12:52 PM
#2

thermostats, spark plugs, fuel filters, change lower unit oil

Posted by whalerman on 11/23/09 - 12:54 PM
#3

Hi, check the plastic pee nozzle for trash, remove the hose and use a small thin wire to insert into the nozzle. Do both nozzles and try motors. If that didn't help then pumps changed out. Also look at the thermos and relief valve for trash. Good luck

Posted by CES on 11/23/09 - 12:56 PM
#4

Since you don't know when the last time the impellers were replaced, go ahead and replace them. The stream on my 40hp was weak and though I was assured that the motor was checked out by a certified and trustworthy mechanic before I bought it, the impeller was still bad.

If I were you, in addition what Matt said above, I'd replace the impellers. Sooner than later is advisable.

Edited by CES on 11/23/09 - 5:37 PM

Posted by Mark Sr on 11/23/09 - 1:20 PM
#5

Thanks a lot for the replies. Although I am quite mechanical when it comes to Toyota 4x4s, outboards are new to me. Is the impeller separate from the water pump or part of it / one in the same?

Posted by moose on 11/23/09 - 1:48 PM
#6

Mark,
As mentioned, if you don't know when they were changed, by all means, do so. If you don't replace the screen on the pickup the impellors will be in vain, as you sill still suck up trash. You may have a clogged passage if that screen has holes in it. Back flushing won't hurt and may wash something out.
Mike

Posted by brooks89 on 11/23/09 - 1:52 PM
#7

the impellor is the heart of the water pump.

Check this site out: http://www.maxrules.com/index.html. Armed with your model specs, model number and serial number you should locate exactly what you need.

Posted by Guts on 11/23/09 - 3:37 PM
#8

brooks89
Cool link thanks..

http://www.maxrules.com/index.htmlindex.html

Posted by Mark Sr on 11/24/09 - 11:04 AM
#9

Thanks again, typically do gaskets for the lower unit re-install come with the water pump kits?

Posted by Tharsheblows on 11/24/09 - 2:06 PM
#10

The complete pump rebuild kit has the gaskets for the port plates, I have never bought just the impellor so I don,t know if it has gaskets, The complete kit is only about $30.00 + or - on my old 70 . The lower unit has only a exhaust donut that should not need changing. Unless like mine when the previous owner reinstalled it was allowed to get out of place and pass through the exhaust chamber which burned it. A small tip from a mechanic to insure that the next pump change will remain easy apply some antiseize grease to the drive shaft spline (the end that goes into the power head) to insure corrosion does not stick it. Just get a manual or info on how the shift linkage is to be dis/reconnected and where the bolts are to be removed. If your 70 is like mine one bolt is hidden under the torque fin. I see from your PP that you are not afraid of tackleing mechanical tasks so you will find this to be easy.

Posted by Derwd24 on 11/24/09 - 2:12 PM
#11

I just bought a complete OEM kit and had to laugh as it comes with a small packet of that spline grease mentioned above, but doesn't come with any of the sealant required for the gaskets. Grease I have plenty of, marine water pump gasket sealant, not so much... Would be nice if they considered that and included a small packet of the stuff.

Yes, best to get the whole kit as it will have all the gaskets including the thin spaghetti gasket for the bottom of the pump housing. The impeller conforms to the shape of the pump housing cup over time and loses its flexability. So time is a factor in impeller life even if the unit has minimal use.

Also meant to add that the intake pick up screens are very easily replaced and well worth doing on both motors while you're doing the pumps as they do seem to get a little brittle over time. Short money if I remember correctly. You can go to the BRP website, access their on line parts catalog and see what that part goes for specifically. IShopMarine also has the same style part look up. The intake screen for your particular engine is $6.63 and the water pump kit is $64.22 They also have Sierra pump kit, but I think it's best to stick with OEM for such parts.

Edited by Derwd24 on 11/24/09 - 2:35 PM

Posted by Mark Sr on 11/27/09 - 2:07 PM
#12

Appreciate the tips everyone. Dave, I ordered new water pump kits from ishopmarine along with inlet screens and some other items. Not sure when I will get the parts as I ordered online Tuesday nite and the parts seem to not have shipped yet, probably due to Thanksgiving.

Hauling the boat out tomorrow to start planning for the job. Thanks again.

Posted by MW on 11/30/09 - 10:14 AM
#13

I'm not too sure about your model but, on mine ('04 Johnson 50 HP), it was not too mechanically challenging but, disconnecting the shift rod assembley is a "PAIN" because, the starter neeeds to be removed to get to it before you can drop the lower unit. You'll want to also lube up the bolt's with "Never seize" since you have them apart, this will make it much easier when you have to change out the pump again. I think that if I i waited 1 more season, removing the bolt's would have been a nightmare. The old pump was "Low" on hours, was in good shape, and pumping fine, there was some wear though, and I replaced it, more important was that I got the lower unit apart and the next change out should go much easier (I swear I thought that the main bolt was gonna snap when I was removing it, I was very relived when it didn't).

Posted by Mark Sr on 12/03/09 - 2:01 PM
#14

Went to haul the Ribside in this afternoon with fresh charges on both batteries. Just for fun I blew in the water pump indicator tube until water came out the inlet holes on the lower unit. I tilted down and started her up - got normal flow, and likely a new nickname from my buddy who was with me.

I was suprised but happy, as I wanted both motors at the ramp. I would be approaching the ramp into a stiff wind and with a strong current. New water pumps came today and I briefly regretted the purchase. Halfway there the buzzer sounded again and I shut the motor down.

The boat is in my yard tonight with both props off, I hope to drop both lower units this weekend - one at a time of course.

Posted by Tharsheblows on 12/03/09 - 3:12 PM
#15

Mark don't regret buying the new pumps. I have seen it suggested more than once that you should change pumps at least every two years no matter how little the motor has been run. When I bought mine used I did not even start it till I changed the pump.

I have a 1973 Mercury 9.9 hp that once sat in storage for 15 years when I put it back in service it did not run hot and had a very strong stream. But because of it's age I changed the impellor. When I opened it up I was surprised that out of four impellor vanes all were missing except one.

My 70 hp is a bit older than yours so I dont know how close it's design will be. But on mine the shift linkage is accesable down in the lower cowling just under the intake. There was nothing to remove to get to it but you needed a 3/8 " ratchet with a 8 " extenison a universal joint and a socket magnet insert. Removal is easy but starting the bolt that combines the shaft to the shift linkage takes a little patience but is not impossible.

Posted by theo on 12/03/09 - 6:00 PM
#16

Mark Sr wrote:
Just for fun I blew in the water pump indicator tube . . . and likely a new nickname from my buddy who was with me.


Keeping it a secret, huh? I have a good friend who loves fishing and fish so much he once gave mouth-to-mouth to a cutthroat trout. Funniest darn thing. We laughed for days!

Posted by MW on 12/03/09 - 11:42 PM
#17

Theo, you guy's should have gotten a pic of that (although I'm sure that everyone was laughing too hard to think of it). Mark, you really want to stay up on "Water Pump" Maint./replacement. The "water pump" is the weakest link on an outboard motor, you CAN'T make a mistake by replacing it too early, it's like an oil change on a car, if you change it too early, you'll only increase the life expectancy of the engine. It also depend's on your area of operation, it's very sandy here, with lot's of sediment in the water, so it's suggested to change out the water pump every 2 years.

Posted by CES on 12/04/09 - 4:09 AM
#18

X2 what Matt said. My plan is to replace mine every two years however I think I may do it after each season now. The lake I usually run in is murky from mud. With that much sediment in the water, I'm sure the water pump on my motor wears more than the average water pump.

I'm glad ur planning on replacing both your water pumps, a little preventive maintenance now will help stave off a larger repair bill later.

Posted by John Fyke on 12/04/09 - 11:10 AM
#19

CES wrote:
Since you don't know when the last time the impellers were replaced, go ahead and replace them. The stream on my 40hp was weak and though I was assured that the motor was checked out by a certified and trustworthy mechanic before I bought it, the impeller was still bad.

If I were you, in addition what Matt said above, I'd replace the impellers. Sooner than later is advisable.


The stream was good on your motor and had no indication of needing replacement. That was up to you. Money talks. There is always something to maintain and it always cost money.

Posted by MW on 12/04/09 - 2:16 PM
#20

The pump can still be worn, even though the "Tell Tale" is working, you'll see the wear mark's on the bottom of the cup of the old metal impeller housing when you remove it. Even a few thousand's of and inch of "wear" on the plate can greatly reduce the water pump's output (water spray's between the impeller and the plate instead of going on to cool the head). If you want, you can install a "Water pump" pressure gauge on your control panel, this will show a reduced amount of "Pound's" of pressure regestering on the guage as the water pump wear's down, and get's "Tired". I feel that it (guage) is more cost, and something else to break, and it's just easier to change out the water pump on a regular schedule.

Posted by Mark Sr on 12/05/09 - 5:10 PM
#21

Rained most of the day here, but I was able to get started. Lower unit is loose, just looking to release the top end of the shift rod tomorrow morning. It appears I will have to remove the starter to get to it though.

I did break the head off the bolt that is up under the directional trim tab. All others came off easy and the LU lube I drained out looked real good.

Posted by MW on 12/06/09 - 12:44 AM
#22

Yea, that's the bolt that likes to break (been there) can you get it out ? A small driver "extention" and "Universal" socket will help when removing the shift linkage, you might need "Shop" support if you can't remove the bolt, glop everything with "Never seize" (not grease) when you re-assemble.

Posted by Mark Sr on 12/06/09 - 5:45 PM
#23

Thanks for the offer in your PM Matt, I was able to drop the lower unit today after releasing the shift rod. I am a little worried about getting the linkage re-attached though. Got the broken bolt out w/ a vise-grip after some PB spray.

It's funny, the impeller looks fine. Looks like I thought it would - a 5ish y.o. water pump that saw relative little use.

It appears I have to take the driveshaft cover off to allow clearance to R&R the water inlet screen.

I might go ahead and take the other LU off, clean them both up, and maybe even paint them while I do some other maintenance. Thanks for all who shared advice.

Edited by Mark Sr on 12/06/09 - 5:46 PM

Posted by MW on 12/07/09 - 12:29 AM
#24

Glad you got that bolt out, the linkage will re-attach, after 5 years of even little use on the motor, the impeller can "SET" (bend in 1 direction), You had to go in there anyway to check thing's out, keep going, ya doing GREAT !