Newbie impeller concern

[Blaw]

I just had mine replaced in my Mercury 115hp OPTIMAX 2-stroke and was told that this needs to be done once a year. I find this hard to believe that Mercury would use a part that has to be replaced every year. Does anyone on here, or maybe a Mercury rep that reads this board, know if Mercury is looking into this or do they just don't care about the customer and are content with using this product? Am I wrong to think this, is this normal for boat motors?

 

[76canaventure]

Re: Newbie impeller concern

Good Morning!
Yes, it's very normal. I change mine once a year as part of my spring routine. It doesn't take very long and an impeller is only worth $30 bucks. (It's cheap insurance, plus my motors are 35 ~ years old, I like to dig around in there once in awhile just to make sure nothing bad is happening.) I think Merc recommends 3 years or 300 hours for the optimax, you can find that info on their website I'm sure. All impellers are a wear item, that's just the nature of the beast, doesn't matter what motor you have. I'm actually amazed that they last as long as they do. Buy a service manual and do it yourself, it's not hard plus you'll save some bucks.
Regards

 

[Star]

Re: Newbie impeller concern

OK that is it! Yes if you run the motor without water at all you should replace your impeller every year. Or if you run in a sandy bog and pump sand through the motor! My 1968 9.5 has not seen a new impeller in 9 years. Know I know all you experts will tell me that my little tinker toy doesn't produce the heat of a 115 but those vanes don't fall off without abuse, or chemical attack.

 

[dlplost]

Re: Newbie impeller concern

I've allways gone 5 years, never had a problem.

 

[Maxz695]

Re: Newbie impeller concern

Although its true that with continuous use the impeller vanes tend not to form the the egg shape of the housing cup, and it also prevents dry rotting. A smaller motor obviously dose not cause the friction a bigger motor would on the impeller. Changing the impeller every year or two is a preventative measure to insure your motor will continue to cool properly. This is called maintenance and is a very inexpensive part to change in order to avoid major repairs. So with that are you willing to risk being out there in the middle of no where and not notice your engine has stopped peeing? are you willing to try to get back to shore with little to no stream? Are you willing to pay Sea Tow 400.00 plus to get you home over a $30 part? This is what you have to ask yourself.

 

[fisherguy123]

Re: Newbie impeller concern

the local merc dealer here works on a lot of ob motors of 40 to 80 hp used in the lobster fishing industry and recommends impellor change every 3 years minimum. They do a lot of full speed to idle in salt water work and I know guys that go through 25 gals of gas per day for about 8 weeks straight . These motors are never flushed with fresh water either and I haven`t heard of many problems if they followed his recommendations.

 

[luckynickles]

Re: Newbie impeller concern

I liked that answer

 

[P3C]

New impeller Chrysler70

New impeller Chrysler70

I have a Chrysler 70 hp. Built in 1973 and sold as new in 1981.
I bought this engine in 1989 as a used motor, in the eary 1990s it was used frequenly every year but since 1996 it has just been left without use.
I think the impeller was exchanged when I bought the engine but not sure.

This spring however I got the thumbs out and decided to get my old boat back on water.
It took some effort to get the old Chrysler running, had to switch all gas tubes since the were in shreads. There were no spark in the plugs either, took some time to figure out the problem, oxide in the distributor.

After these problems the motor was as good as when it left the factory.
It cooled all right also, no heating problems. But after reading posts on this forum concerning impeller issues I decided to change the impeller.

Ordered a new one and got the old one out. It was soft and showed no signs of wear. The wings though were bent after sitting so long in the pump.

Put it all back together and went out on the lake, I was a bit surpriced to see that there were at least twice as much water coming out of the rear of the motor.
Even if the inpeller is old it cools without overheat problems but a new one does the work safer and with much more flow.

 

[G8trbait]

Re: New impeller Chrysler70

Re: New impeller Chrysler70

One thing to check are the metal plates that the impeller sits between. Either the upper housing or the lower plate. My friend's 150 ELPTO SW would overheat at speed but not at idle. He replaced the impeller took the boat out and it did it again. The two plates had been worn enough that the impeller was slipping or something at speed but not at idle. It is easy to see. There will be a ring dug into the metal plate nearest to where the prop shaft goes through. My 2003 90 ELPTO unfortunately doesn't have a cup so I have to buy the entire stainless steel housing for 60 plus shipping.

 

[Blaw]

Re: New impeller Chrysler70

Re: New impeller Chrysler70

New impeller, sand cleaned out, runs like new.