Update! Alarm what's next ! Tests today

[Steveditt]

Todays Poppet Valve Replacement

This morning removed the Poppet Valve cover and it was very clean ,removed the bushing installed new spring and stopper ,started the engine at idle less than 10 minutes overheat thermal gun both cylinders hot .Shut it down . Strange the other day it idle for 40 minutes without overheating .

Arrived Home over an hour away to find 28 new trailer roller arrived installed them this afternoon,pulling the boat tomorrow morning to bring it home to pull the lower unit inspect the new water pump kit that was installed in April .

Also arrived today two gallons of Rydlyme , Before returning to my slip I'll test it locally in the Hudson River , it still overheat most likely will go to the Yamaha dealer for the heads as I expect that's not going to go well .

Been retired awhile so maybe its time to spend some of that 401 money I'll never spend on myself for a new engine .

Called Boat U/S this evening as I luckily upgraded this year to **** Unlimited towing from a post on one of the sites about a special show offer been a member since 97 no problem upgraded my membership ,so they said call in the morning a they will tow me to the ramp . As my five year GS said this evening cheer up Grandpa !

[TownsendsFJR1300]

If it's NOT overheating on MUFFS and the power-head flusher, you don't have a salt build up corrosion / blockage issue in the cooling passages..

It would overheat ALL the time, especially at higher RPM's.

My $'s on something with the WP, SS cup, impeller or housing..
Check that the cup didn't spin inside the housing, etc..

Your simply not getting enough water to the top end

[Jason2tpa]

If it's NOT overheating on MUFFS and the power-head flusher, you don't have a salt build up corrosion / blockage issue in the cooling passages..

It would overheat ALL the time, especially at higher RPM's.

Scott...in theory, if the cooling system was experiencing an overload of corrosion–but in it's infancy rather than full blown (no water circulation)–wouldn't providing the system with an increase flow rate of water be just enough to prevent high temp alarm from triggering?

Technically, an outboards centrifugal pump output is limited by 3 factors: water available to pull, resistance down stream, and speed of crank shaft. However, only 1 of these 3 factors need altering to result in no water circulation.

But in this OP's scenario, if running engine on muffs AND power head flushing simultaneously, the added water pressure provided by the power head flush could be just enough to overcome the resistance caused by corrosion. I don't know, just spitballing here. My 1st profession primarily dealt with occlusion and non-occlusive pumps, fluid dynamics, and the physics associated with both. So whenever a scenario comes up like we have here my science brain kicks into overdrive, and the "what if's" tumble out.

[Steveditt]

Money

Well Scott I would have lost my bet as I convinced myself it was the Poppet , I get the blockage part which makes sense except both sides heat equally hot ,lower pistons are cooler than the top . The only issue I had replacing the pump was the barb fitting for the speedometer broke ,I removed it the new one was a little tricky getting back in is it possible if that somehow came out you could lose enough water pressure and I used the boat 25 times . Trailing the boat home today hopefully will update this evening on what I found or not found !

[TownsendsFJR1300]

Well Scott I would have lost my bet as I convinced myself it was the Poppet , I get the blockage part which makes sense except both sides heat equally hot ,lower pistons are cooler than the top . The only issue I had replacing the pump was the barb fitting for the speedometer broke ,I removed it the new one was a little tricky getting back in is it possible if that somehow came out you could lose enough water pressure and I used the boat 25 times . Trailing the boat home today hopefully will update this evening on what I found or not found !

The broke speedometer tube fitting won't affect your cooling.

Just in testing, try both muffs and power-head flusher and check temps.

If their staying steady (cool), its a water volume issue.

*Both heads NOW getting hot confirms your not getting enough water at slow RPM's. Possibly getting worse...

Quote: "lower pistons are cooler than the top" . This goes against the passages being clogged and most importantly, re-affirms there's NOT enough water getting to the top of the engine.


IME, one 200 Yam, V6, we found the cooling passages, MOSTLY at the lower end of the passages easily 98% clogged. That engine would run to approx 4,200 RPM all day long. Higher than that, alert and engine RPM reduction.

Once cleaned out (and it was SOLID), engine ran like a top...


Good luck today, hopefully some headway.

[Steveditt]

And THe WINNER IS !!!

towed to the ramp from my slip ,trailered home , installed ears ran the engine for 25 minutes no alarm took the cover off both thermostats 125 -130 cooler temps lower pistons ,no over heat . Removed lower unit turned the shaft by hand 3/4 around felt a clunk ,around again clunk ,broke the pump down and the impeller was split on the bottom at the key way .This was a new Yamaha pump kit installed in April used 20 times , called the local dealer [hour away ] has one in stock going up tomorrow . Flushed the block while the lower unit was off with Rydlyme clamping off the telltale , removing the thermostats ,flushing with the flush attachment which was simple having a five gallon bucket under lower unit with an electric pump flushed for a few hours without much results as far as grit in the bucket .So the pump guys win well its not official but I'm pretty confident .

I just want to thank everyone for your suggestions I certainly learned a lot . Steve

[pstephens46]

You didn't install the impeller upside down, did you!!!??? There is a one way notch for the key.

Grease is your friend when installing these things. That way things don't have to be forced. Not pointing the finger, just saying!!!

[99yam40]

thanks for the up date.

A friend on mine had a impeller on a C70 break loose from the plastic collar that the key locks it to shaft with.
never heard of one splitting.

I had a impeller lose vanes in less than a year.
it was new off the shelf item at yamaha dealer.
I think it may have been sitting on the shelf for too long due to people buying kits instead of just an impeller , but I may have fired the motor up with lower unit out of the water after drifting very shallow.
Just for a second or 2, you can tell by the noised when lower is up in out of the water

[TownsendsFJR1300]

It's pretty unusual for that to split at the collar...

That would explain lack of water volume to the rest of the engine..

Couple things,

Get the entire kit if possible (seals, etc).

Check under the wear plate at the upper seal. Make sure the tension spring is STILL there. (they tend to break/go away over time).

Lastly, if you don't have the PROPER Yamaha Waterproof grease for the drive-shaft- mid section BUSHING SPECIFICALLY, get some.. Any other non marine (specific for this section) will result in a do over...

Plz update once "road" tested!



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[TownsendsFJR1300]

Re the splitting, make sure the shaft is NOT buggered up (from key removal) and slightly larger than it should be.

If you need to use alot of force to get the impeller on, there's an issue. It's NOT hard to bugger up the shaft pulling the key out. I'm assuming you did and replaced the wear plate as well..

If the key isn't fully seated, super tight, that could definitely cause undue stress and possibly split that collar.

I did my WP with a kit a couple months ago. The key was a PIA to remove. Getting back in, not much easier.

Once fully seated, a slight tough of grease and the impeller went on by hand, no pounding (except for later setting the retainer)




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[Steveditt]

Learned a few new things !

watched a youtube video today by Marine tech tools before starting the replacement two things he emphasized ,centering and setting of the woodruff key he uses a special tool to set the spacer and retaining collar both things I don't remember doing in April . April installation went very easy woodruff key ,impeller slide right down no hammering ,set the veins clockwise turning the shaft . It worked fine for twenty trips then it started to OH then the impeller would catch the grove and the water pump worked fine a few minutes later the shaft would spin around jumping in and out of the grove causing the OH it was confusing.

My woodfuff key was on a slight angle and the retaining collar slide right off today completely different then the one I had removed in April which I installed three years ago .

Was the split on the bottom of the impelled causing the woodruff key to jump out of the grove ?,I did the work and thought I did everything correct until todays video ,If centering and setting the key and setting the retainer that critical then its on me , Spent some extra time on those items today I'm very confident things will be trouble free now ,plus new poppet and a Rydlyme flush which was over do .Hopefully get back in the water soon .
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Posts: 62
Joined: Nov Sun 11, 2012 4:22 pm

[TownsendsFJR1300]

Setting the key initially (getting started) is the hard part. I think I used a LARGE channel lock pliers..

Once it's holding on it's own, I used a 3/8", 3" extension and gently tapped the key in until fully seated.

There isn't much sticking out but as you noted, the impeller fits tight.

You should also PULL UP on the drive shaft, while rotating and use a tool (I used a large open end wrench that JUST fit around the driveshaft) and tap down on the retainer clips.

This basically takes the slop out , (like a tick from the LU-won't hurt anything, just annoying) of the LU at idle.

It is in the shop manual and often over looked...


Just to confirm, you did turn the drive-shaft (looking down) clockwise as you pushed the cup/housing down, correct?


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[Steveditt]

Yep

Used the channel locks and then tapped the woodruff with a small hammer , used the wrench also to tap down the retainer and yes down clockwise .

[Jason2tpa]

....and grease. Cover all interior surfaces of housing that contacts impeller, including base plate, gaskets, water tube pick up, etc. Marine grease is your friend with this install.

[TownsendsFJR1300]

....and grease. Cover all interior surfaces of housing that contacts impeller, including base plate, gaskets, water tube pick up, etc. Marine grease is your friend with this install.

Plus 1 ^^ BUT, I used Palmolive liquid dish soap on the impeller /cup when installing the cup. (I believe the manual does call for grease).

I didn't want the excess grease "build up" inside that cup (possibly pumped into the power head, etc-and there to stay as it's waterproof) when the Palmolive works just as well and washes away easily.

I also put a very thin layer on all alignment pins, LU to mid-section "contact surfaces", etc...


Sounds like your set to go Steve!





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