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Mercruiser 350 Mag MPI Impeller (Kit) part #(s)
Posted: June 9th, 2021, 5:45 pm
by Batwing
Does anyone know the part number(s) for the impeller kit for the Mercruiser 350? Additionally, how challenging is it to replace myself vs. the marina shop?
Thanks for any input
Re: Mercruiser 350 Mag MPI Impeller (Kit) part #(s)
Posted: June 9th, 2021, 10:14 pm
by Viper
46-807151A14 is the body/impeller kit. How challenging it is to replace really depends on accessibility and your mechanical aptitude. One engine is usually easier to do than the other.
Re: Mercruiser 350 Mag MPI Impeller (Kit) part #(s)
Posted: June 9th, 2021, 10:16 pm
by tomschauer
It depends on the drives. For 1999 i suspect you have bravo 1 or 3's. All of the bravos use the same engine mounted raw water pump, no matter what engine size. The challenge will be access. if you can easily get to the pumps, its a really simple job.
If you happen to have alpha drives, its a different story. The boat need to be out of the water and you need to drop the lower half of the out drive to replace the impellers.
Re: Mercruiser 350 Mag MPI Impeller (Kit) part #(s)
Posted: June 10th, 2021, 2:12 pm
by Batwing
Thanks for the quick reply. Not certain on Alpha or Bravo. I'll investigate further.
Re: Mercruiser 350 Mag MPI Impeller (Kit) part #(s)
Posted: June 10th, 2021, 3:15 pm
by bud37
I think 350 mariners are all inboard v drives.
Re: Mercruiser 350 Mag MPI Impeller (Kit) part #(s)
Posted: June 10th, 2021, 9:14 pm
by Viper
Ya inboards, so the pump kit is the number I posted.
Re: Mercruiser 350 Mag MPI Impeller (Kit) part #(s)
Posted: June 11th, 2021, 9:59 am
by Cooler
If you do it yourself, make sure to lubricate the impellers when you insert them. Crazy how many people think they can ignore such a simple task. Finally, get the belt adjusted correctly. Kinda a PITA on one side due to access.

er
Re: Mercruiser 350 Mag MPI Impeller (Kit) part #(s)
Posted: June 11th, 2021, 11:55 pm
by RGrew176
Just out of curiosity when you lubricate the impellers what do you lubricate with. In a previous installation of new impellers the mechanic used silicone spray to lube them with prior to installation. I've heard some people use vegetable oil.
Re: Mercruiser 350 Mag MPI Impeller (Kit) part #(s)
Posted: June 12th, 2021, 5:48 am
by throwback2
RGrew176 wrote:Source of the post Just out of curiosity when you lubricate the impellers what do you lubricate with. In a previous installation of new impellers the mechanic used silicone spray to lube them with prior to installation. I've heard some people use vegetable oil.
I've always used dish soap.With the exhaust on my boat being underwater,the bubbles show that the pump is working.
Re: Mercruiser 350 Mag MPI Impeller (Kit) part #(s)
Posted: June 12th, 2021, 9:01 am
by Viper
Depending on the brand, some kits come with a little packet of grease/lubricant. The best was the Onan impeller kits that came with a large packet of it. Always had some in my tool box. The packets are much smaller now so I rarely have that anymore. Dish soap is what I use most of the time, does the job just fine, and you don't need much. It's only needed to cover an initial dry startup. Once water gets into the pump, it does the lubricating.