Wasp nest in water inlet

[IronInitiative]

I have a 70 Hp Yamaha on a 20 ft pontoon that set in storage for 4 years. After some clean up and some idle time on the muffs I gave the engine a test run. Everything went well, smooth acceleration and smooth idling. But while waiting to trailer the boat the alarm sounded. After sitting and cooling down I restarted the engine with no alarm and loaded onto trailer. That's when I noticed that the inlets are being blocked by wasp nests. The question is this: Should I just remove the lower unit and clean out the debris or should I replace the water pump. I believe the pump was replaced shortly before going into storage.

[boscoe99]

If the impeller/pump is not damaged I would just clean out the water passages to the pump. But if they are damaged then I would replace them.

Those critters are always looking for a home.

Would not be a bad idea to remove the top cowling and carefully inspect all parts of the motor. Including the air intake silencer. Mud daubers can go in there and make a home. Said home can break loose and get ingested by the motor. It won't be good.

Take a look under the dash and see what you see. Might be some critter homes up in the dark hidey places.

[Sequoiha]

The boat has been sitting 4 years, put a water pump kit in it.

[TownsendsFJR1300]

The boat has been sitting 4 years, put a water pump kit in it.

Plus 1^^.

It's way over due for a pump and spline re-grease. You can bet the impeller has a bad "set" in it...

I'd change the LU oil while it's off and convenient as well..Again, that's overdue as well.

[boscoe99]

One good thing about seeking answers on public forums is that generally one can find what ever answer it is that they would like to find.

Up, down, east, west, yes, no, red, blue, use additives, don't use additives, Yamaha, the rest, it does not matter.

You gotta love the innerweb. Something for everyone.

[TownsendsFJR1300]

One good thing about seeking answers on public forums is that generally one can find what ever answer it is that they would like to find.

Up, down, east, west, yes, no, red, blue, use additives, don't use additives, Yamaha, the rest, it does not matter.

You gotta love the innerweb. Something for everyone.

Do you believe he should leave a 4 year old impeller in there (especially that hasn't been used) and WILL have a set?

[boscoe99]

Do you believe he should leave a 4 year old impeller in there (especially that hasn't been used) and WILL have a set?

I don't know.

What I do know is that none of the engine makers specify replacing either the impeller or the water pump kit if and when a motor has been sitting for any number of years prior to that motor being placed into service for the first time. Certainly Yamaha does not specify for it to be done.

If a dealer has a 1999 four stroke sitting in his inventory and he sells that motor today, Yamaha will warrant that the impeller is hunky dory.

Yamaha installs a new pump at the factory and it sits for years or the owner installs the pump and it sits for years. I don't know if there will be a difference.

Now if the impeller did take a set would centrifugal force not over come that set and cause the vanes of the impeller to seat against the cup in which it rides? I don't know.

Like I said, maybe every questioner should be given multiple answers. He can then select the one that he most wants to hear.

[fastback4]

just wondering, how long would it take a master tech to r&r a water pump say on a 2005 2 stroke 90hp considering all parts and tools in hand? In my day I could overhaul a GM 2 speed power glide, with parts in hand, just under 1 hour.

[TownsendsFJR1300]

just wondering, how long would it take a master tech to r&r a water pump say on a 2005 2 stroke 90hp considering all parts and tools in hand? In my day I could overhaul a GM 2 speed power glide, with parts in hand, just under 1 hour.

If you can overhaul a PG in a hour, you can EASILY replace all the WP parts, (kit and all), in about the same time.

The hardest part (if you don't have two sets of hands) is simply putting the LU BACK into the midsection (be-tween alignment and weight).

Here' a video, pretty much same procedure, no special tools required:
https://www.youtube.com/watch?v=BRQo3rYTj-U

You should use the proper Yamaha Waterproof grease, regular wheel bearing grease, etc, won't cut it..


For me, I can change out the kit, wear plate, change the LU oil too, once on the bench, in a little over an hour..

Correction, actually, the last MT that did mine (bout 3 years ago) slapped that brown sealer all over the place (which took longer to remove) than the job itself. Grease alone holds the seals just fine.



Boscoe, I have yet to see an impeller come out (outside a year) that does NOT have at least a set. Obviously, inspecting will show if it does or not, As Yamaha DOES direct inspection 100 hours or EVERY YEAR.



Now we don't know how much BEFORE the impeller was changed out, IF EVER... That's NOT even counting the OVERHEAT alarm the Op's ALREADY experienced..

For the cheapish price, the unit already apart for inspection, not changing a four year old impeller (at least) is a no brainer...


As Rodbolt often posts, run it till it's dead, then bitch about it..


Recently, my F150's LU WP being done by myself (with all the nasty sealer on it before I scraped it off the housing):







.

[99yam40]

If paying someone to inspect it would probably be cheaper to just have them replace with new.
That way you are not paying to have parts cleaned up.

If doing it yourself remove inspect and replace if it looks like it needs it, like Boscoe said in the beginning.

Biggest fear most have is the drive shaft rusted into the crankshaft or breaking off bolts and having to drill them also

[TownsendsFJR1300]

If paying someone to inspect it would probably be cheaper to just have them replace with new.
That way you are not paying to have parts cleaned up.

If doing it yourself remove inspect and replace if it looks like it needs it, like Boscoe said in the beginning.

Biggest fear most have is the drive shaft rusted into the crankshaft or breaking off bolts and having to drill them also

Just an FYI, when I had the MT do mine 3 years ago, they wouldn't just replace JUST the impeller.

ONLY a kit as if there's an issue (and it has to come apart again), their "eating it"


I only had them do it as they warned me about the upper drive shaft seals failing due to time (I wasn't at the time comfy doing those) and sure enough, the pressure spring / seal failed /was gone.



.

[Sequoiha]

I can do one in about 35 minutes,

[Sequoiha]

Boscoe, do you actually work on them or are you just extremely good at information,, just asking, not insinuating.

[99yam40]

Boscoe, do you actually work on them or are you just extremely good at information,, just asking, not insinuating.

Boscoe is several sets of encyclopedias on all sorts of things, but I think retired and enjoying life

[TownsendsFJR1300]

Boscoe, do you actually work on them or are you just extremely good at information,, just asking, not insinuating.

As there's no response, I know Boscoe used to work for Yamaha headquarters. (PM'ed me when he first came here).

Where folks (I think dealers and customers) would CALL for help when stuck with mechanical issue's.

Thus, ALL the diagrams, data, info, us regular folks would NOT have access to...

He's posted about working on his own yammy, but as professional mechanic, I don't believe so..