How often do folks change their impeller?

[Irv964]

I was told 3 yrs is the average, my dealer was going to change out mine this year but said since I didn't purchase it until late in the year(06) I could go one more year? (2007 90hp Merc 4 stroke)
After talking with my buddy this week-end, he said he hasn't changed his impeller on his 98 Merc 115 Optimax since new? Is he sh**ing me or has he just been really lucky? He stated his stream is still really strong and the temp is always very close. (he does use the boat quite often)
I was also informed that the original stock impeller will be the best impeller one will ever have, the replacement impeller is never quite as good as the original from the factory, any truth to this?..........Irv964

 

[hamit59]

Re: How often do folks change their impeller?

I replace my pump impeller ever two yrs 50 4stroke merc. It's not worth 4 grand to let it go longer than that.I drain the lower lube every 6 months at the same time I change the oil and filter. Use only 25-40 oil as these things don't like the 10-40 oil, it will get you by for a weekend or so but it's better to use 25- 40 it's thicker at a lower temps than 10-40. I use merc lower lube
it's the best I have ever used It will mix with water if you do loose a seal and still lube some what. Now that we are doing all this it's a good time to grease the motor top to bottom with a good ep grease. IT would be a good time also to treat your unused fuel and run it though the motor you don't want to pay to clean the fuel system.

Just my 2 cents worth
Hamit
BT1 USN ret

 

[Irv964]

Re: How often do folks change their impeller?

I replace my pump impeller ever two yrs 50 4stroke merc. It's not worth 4 grand to let it go longer than that.I drain the lower lube every 6 months at the same time I change the oil and filter. Use only 25-40 oil as these things don't like the 10-40 oil, it will get you by for a weekend or so but it's better to use 25- 40 it's thicker at a lower temps than 10-40. I use merc lower lube
it's the best I have ever used It will mix with water if you do loose a seal and still lube some what. Now that we are doing all this it's a good time to grease the motor top to bottom with a good ep grease. IT would be a good time also to treat your unused fuel and run it though the motor you don't want to pay to clean the fuel system.

Just my 2 cents worth
Hamit
BT1 USN ret

Not really sure I was after oil change intervals and brand info but thanks anyways
Any one else?..............Irv964

 

[ne7800]

Re: How often do folks change their impeller?

I belive every two years is the general rule of thumb

 

[joed]

Re: How often do folks change their impeller?

Mine' been in since I bought it in 95. Still see water out pee hole so I know its working. Thinking of changing it before next season.

 

[Irv964]

Re: How often do folks change their impeller?

Mine' been in since I bought it in 95. Still see water out pee hole so I know its working. Thinking of changing it before next season.

1995? Wow, I thought 1998 was pushing it? I guess I will just keep an eye on mine over the next couple of years and see how it goes?
Like what was stated above, I don't want to push my luck as these motors are pricey!
Also, has anyone installed a water pressure gauge on these Merc 4 strokes? Was it difficult?............Thanks...............Irv964

 

[j_martin]

Re: How often do folks change their impeller?

I run a 20 year old V6. Impeller, as well as fuel pump kit is considered annual maintenence.

Would rather have it rich and cool than have to do major metal work on this beast.

hope it helps
John

 

[stubbstheman88]

Re: How often do folks change their impeller?

well s&*t i have my 65 horse from 1968 and the immpeller is still original!! and it works fine!!

 

[hkeiner]

Re: How often do folks change their impeller?

Most think it wise to replace the impeller long before it is LIKELY to fail. While the impeller is not likely to fail immediately after two years, the longer the wait, the more likely it is to fail. The probaility of failure over time is kind of like a bell shaped curve, with some failing way too early, some lasting a very long time, and with most lasting somewhere in between. The real problem is that there is often little advance notice of sudden failure, which can cause serious damage to the motor. Temp gauge and water pressure gauge are helpful to monitor gradual deterioration of the impeller but they may not provide enough warning of a sudden failure. Having said this, congrats to those that have risked not replacing the impeller for long periods and have had no problems.

 

[Irv964]

Re: How often do folks change their impeller?

1968? Is the boat used every year? Were the old ones made of metal or something a lot stronger/tougher than todays impellers?

Speaking of impellers, who has changed them on these newer 4 stroke engines? I was looking at mine (07 90 Merc 4 stroke) and can't figure out how they get at it? My old Nissan 2 stroke was easy, you unbolted 4-6 bolts on the lower unit and everything came down easy. On these newer 4 strokes I can't even see a split where the lower unit comes apart?? ..............Irv964

 

[rolmops]

Re: How often do folks change their impeller?

Impellers will last a lot longer when only used in fresh water and never near sand or gravel.
Often it is dry rot that will kill the impeller.Not regular use.
For the 20 minutes that it takes and the $10 (Iboats aftermarket) that it costs,it is not very smart to risk getting stuck on the lake in a thunderstorm with a blown engine because you did not change the impeller regularly.

 

[mthieme]

Re: How often do folks change their impeller?

I replace it when needed. I have a 2000 Merc 25 that has the original one in it. It will be replaced soon.
I have a OMC that had one that lasted 20 years - 2000+ hours - and didn't look terrible when I replaced it this spring.
I have come upon three used Mercs this season, one was literally desintigrated - had to blow it out the exhaust, the other lasted all season - 200-300 hours, but needs replaced, last a project not running yet will be replaced.
On average though, I get about 5 years out of an impeller.

 

[MERIT6419]

Re: How often do folks change their impeller?

just keep an eye on the temp if it gets hot that is the first place I go. I always keep an eye on oil pressure and water temp.

 

[skillman]

Re: How often do folks change their impeller?

I have a pair of 03' 250 mercs that still have the original impeller in them since new, still a good stream, temp is cool, and water pressure is still as good as new. I figure if i see one of those things a little off from normal it might be time for new impellers. I guess it's just a matter of personal preference.

 

[stubbstheman88]

Re: How often do folks change their impeller?

well i dont really know what the impeller is made of though but i think its plastic and i got a question for anyone.. how hard is it to change the impeller on a 1968 65 horse how long should it take and do you have to really be mechanically proficient to do it?