Yamaha water pump vs. Aftermarket?

[fastkenny]

Anyone have experience with Sierra parts? Many sites including this one provide Sierra for Yamaha water pump kits. I'd prefer to get the OEM, but I can't tell if the Yamaha kit comes with the pump housing (yamaha part 6G5-W0078-A1-00, $43) The parts guy at the yamaha dealer didn't know.<br /><br />Anyone do a water pump lately and shop the parts?<br /><br /><br />THANKS

 

[zzzzz]

Re: Yamaha water pump vs. Aftermarket?

I just looked at a 6g5 kit on our shelves- no housing...we sell some Sierra parts and from looking at the mold marks in the impeller they look identical to genuine Yammy ...I've also heard from different sources that Sierra does make OEM parts for some engine manufacturers

 

[fastkenny]

Re: Yamaha water pump vs. Aftermarket?

thanks!

 

[rodbolt]

Re: Yamaha water pump vs. Aftermarket?

fastkenny<br /> nope that kit only contains everything but the housing and the water tube grommet. unless your housing is damaged its ok for reuse. the reason I replace the housings on the jonnyrudes is the brass insert for the bolts likes to split. the small housing mercs like to warp and melt if they even think about getting hot. but so far not much trouble with the yam v4 v6 housings unless the pump was run dry. I asked once but cant remember, are these motors 20 or 25 inch ?

 

[fastkenny]

Re: Yamaha water pump vs. Aftermarket?

thanks for the info<br /><br />these are 25" motors, why do you ask?

 

[rodbolt]

Re: Yamaha water pump vs. Aftermarket?

on a 25" motor , when the gearcase is removed carefully use a flashlight your eyes and your fingers to inspect the drive shaft bushing in the exhaust housing. its retained by a circlip. the corrosion will build between the housing and the bushing OD. it can destroy a shaft and it can sometimes clamp the shaft so hard that the starter cant turn it. its not hard to check/replace but it needs to be done. the 20" motor does not have it.<br /> thats why I asked.

 

[fastkenny]

Re: Yamaha water pump vs. Aftermarket?

Thanks yet again!<br /><br />This is the stuff that never shows up in the manual that otherwise gets learned the hard way (paid for in time and $) after doing it a hundred or so times.<br /><br />I really appreciate your advice and the time you spend on this site. I'll let you know how it goes<br /><br />BTW - how is a leakdown test done? I know what it checks and why it's important, just not sure how to do it. any special tools needed besides a compression guage?

 

[rodbolt]

Re: Yamaha water pump vs. Aftermarket?

cant use a compression gauge. its a special two gauge set that allows a set pressure into the cylinder with another gauge that measures airflow to maintain the set pressure in the cyl. the amount of make upair is marked in a percentage. most manufactures allow 15% I tear two strokes down at 12%. its a lot more accurate than a compression test but not normally used on routine outboard service on older two strokes unless a sealing problem is suspected.

 

[fastkenny]

Re: Yamaha water pump vs. Aftermarket?

got it, thanks<br /><br />no need for a leakdown test now, if I ever get to that point, i'll take it to a shop - no need for me to invest in tools like that

 

[Osprey]

Re: Yamaha water pump vs. Aftermarket?

Be careful with aftermarket impellers. Some use a plastic shaft bushing rather than the Yamaha original which I believe all have a metal bushing. This is the center piece that is molded into the impeller, with the slot for the drift-key.<br /><br />My experience was that I purchased a boat with used motor. Owner glowingly produced receipts showing the water-pump had just been done a couple months prior. After running for about three months last summer, we were offshore and the overheat alarm goes off. After limping back home and pulling the lower unit, found that the aftermarket impellers plastic bushing had torn out and allowed the mainshaft with drift-key to spin inside the impeller at anything over about 900 RPM's. I will never use aftermarket again. The couple bucks you save is not remotely worth the potiential downside.

 

[fastkenny]

Re: Yamaha water pump vs. Aftermarket?

thanks, osprey<br /><br />i agree. i found a great online source of discounted yamaha oem parts.<br /><br />in fairness, i looked at iboats first, but they only offer aftermarket