intermittent water pump 1995 yamaha 9.9

[backwoods]

Having an issue with intermittent peeing water out of the telltale on my 9.9 four stroke. I have no previous history on this kicker motor so when I received it I went thru the oils, filters, water pump, plugs, thermastat(at a later point) carb build ect.. runs great starts instantly. My only problem is the water pump..It pisses water out randomly no ryme no reason. After checking the water punp a couple of times and checking to see if water comes up to the power head (It does randomly) I am now focusing towards an exhaust/air issue? When the telltale decides to release warm water seems fine then it will quit, spit and you can put your finger on the telltale or at the power head water tube and you can feel air pressure - I did this at the lake today, covered the watertube at the power head and air bubbles came out of the water intake...the water pump somehow is getting air pressure from, somewhere?? I ruled out upper end problems cuz the water fails to reach the power plant - intermittently.

I'm at a loss

Rodbolt - you have the knowledge
anyone....

[99yam40]

could be exhaust ,
just a thought

[rodbolt17]

tell tale water comes from the thermostat and the two small nipples on the port side of the head.
those two nipples are known to clog and there isn't a good way to clean them.
a leakdown test can tell you if a headgasket is leaking.

[backwoods]

There possibly could be issues there but my immediate issue is the intermittent water pumping from the water pump, sometimes the pump will push water to the base of the power head (where it first comes out from the lower end and then it quits. No rhyme or reason- rpm, in the lake, using dog ears....the pump is mechanically simple and if it can pump water for a few minutes what the heck stops it from pumping the next minute?? Like I say- this is issue starts before we get to the thermostat or the other tubes or head when it quits spitting water I can pull the tube where it first comes out at top from the lower end and no water will come out, if you plug the tube with your finger or change rpm's or just wait a few moments it will start pumping again. It's confusing!!! No rhyme or reason it will squirt water for seconds - a minute - a few minutes then go back to just spitting air.
I was hoping someone may have experienced this, I may need to do a complete disassemble..

Could water pressure bleed out of the top of the water pump housing where the drive shaft goes thru it?

[TownsendsFJR1300]

I'm not sure how / why you believe the WP isn't pumping.

When its bolted up to the engine, you can't see/tell except when it/if pumps water to the powerhead. (maybe I missed/misunderstood something).

I'd be checking those two small nipples and all the water hoses

Is it clogged up with salt inside the water passages? Flushed regularly if used in salt water??

If not, something to consider, read this thread;

http://www.yamahaoutboardparts.com/f...g-th19434.html

[backwoods]

Scott
I say it is not pumping because I am not getting water to the power head - intermittently. I am checking the water flow at the point it comes from the water pump in the lower end thru the water tube that comes up thru the bracket unit, this is the point that the water line splits and goes to the power head. I am "intermittently" getting water at this point so it makes any issues in the power head irrelevant, I am not getting a constant flow of water from the water pump, like I say there is no rhyme or reason to the water flow or lack of water flow - for unknown reasons this water pump will not continuously pump water.
I intermittently get air or water out of the water tube before it even reaches the power head - when I do get water out of the tube the pressure does not appear to be as strong as the pressure that comes out of my 115 motor.
I'm at a loss....it is not making sense....

[TownsendsFJR1300]

Ok, I understand now.

When you did the water pump, did YOU REPLACE IT (or someone else)?

Either yes or no, as you posted, sounds like the issue is in the pump/LU if your pumping air.

The impeller DOES have to go on it a certain direction(it won't flip the vanes over if you would, if installed incorrectly). The impeller obviously has to be placed so when the engine is cranked, the vanes follow the shaft (basic stuff you probably already know).

Did you replace the water pump with an entire kit or just the impellor?

If not the kit, I would be investing in the entire kit (lower plate too as well as all o-rings).

If you did use a kit, (I think you know), its time to pull the LU off again and re-check EVERYTHING, ALL O-rings properly seated, all in place, the SS cup correctly oriented, etc.

If the LU has removable intake screens, pull them, shoot some water up therre and make sure their clear..

I don't know what seals, water tube style you have, but peek up there with a good flash light checking for any bad/leaking o-rings that might be picking up air..

Another set of eye's (familiar with it) couldn't hurt should you be missing something..

Good luck and please post how it proceeds...

[rodbolt17]

one of us is confuzzled.
there is a brass tube that goes into the pump outlet when you install the lower.
from there this tube does NOT split and goes into the powerhead adapter just aft of the crankshaft area,from there it passes through the powerhead gasket and into the block.
all those rubber tubes,speedometer line excluded, that are on the port side of the motor are DISCHARGE lines.
the line at the top of the T-stat housing and both lines coming from the port side of the cyl head, all DISCHARGE.
no way to MONITOR what the pump is actually doing.
yes the ex cover area and those two passages from the ex cover area to the two nipples are prone to clog.
DO NOT compare it with your 115.
aint gonna happen.

[backwoods]

Thanks Scott and rodbolt for your replies.
I needed a break and ran to Shelter Cove (ca north west coast) to chase some salmon - we ended up with plenty of rock fish and lingcod - zero salmon. we had another larger boat to use so we did not use this Arima with the 9.9 water issue.

I have rechecked this pump a number of times, but I am going to disassemble the lower and start again slowly and anylize every step. The water pump itself is a simple operating part and it only goes on one way, the shaft key is in place. the only part I did not change was the water pump housing -although it does look ok the housing slips over the shaft fairly loose so that may be something to investigate.

Rod, I am the confuzzled one.
I was not comparing these engines, but I did not have complete understanding of the water flow. Now I understand it as you explain it. I was thinking the water took a direct route up and I thought those may be inlet lines although was confused because the telltale hose is right there with them.
So now I am back to the earlier prognosis of plugged up water chambers as these hoses are clear....

I'll check those nipples first, then exhaust cover, then the cylinder head...
Or could you recommend a different order/alternative?

Thanks again for the routing of the water, I wished I had a understanding of that weeks ago.......

[TownsendsFJR1300]

You probably already know but;

You are familiar that the impeller "arms" have to be facing a certain way when assembling. If you turn the driveshaft (maybe with a helper) in the normal running, direction as you place the Cup over the impeller, the "arms" will be correct position. Just confirming...

Just for S&G's, can you hook up a garden hose to the water intake of the power head? Run the water and see how it performs. If it acts the same, the issue is likely in the powerhead picking up air.. (Make sure that intake pipe DOESN'T GET PULLED DOWN). A garden hose with no end and shimmed with duct tape may be necessary.


Another member had an impeller loose some very small pieces that went into the power head.

[backwoods]

Yes, the shaft is rotated in a certain direction at assembly of the impeller. (I found limited instruction on this on the 9.9 so I was not sure it mattered).

I do plan on doing this job over again step by step so I will manually push water up the water tube to see how it reacts.

Rodbolt really clarified my thought process by explaining the water circulation. This engine does have a good amount of salt build up so I plan on doing alot of cleaning in the exhaust cover and possibly pull the head off for further cleaning. This was the direction I was going weeks ago when a friend convinced me it had to be all lower end water pump problem....it's time to cover all the bases and get this boat on the water........

[backwoods]

FINALLY!!!!!
I am still uncertain why the water flow was intermittent but now she pee's freely with more pressure...

The fix ended up being clearing all the clogged water ports in the exhaust cover and cylinder head.
It is a fairly simple job to pull the exhaust cover on the port side of the power head and clean out the water ports by scraping and picking at the built up salt corrosion and then drilling thru the smaller ports.
I cleared the cylinder head water channels that are on the port side of the head by pulling the valve cover off to get access to the factory plugs that plug the water channels that were machined thru the head from the factory. These water channels flow from the exhaust port (this is cheating but it saves the time and hassle of removing the cylinder head). You need to drill thru the plugs which then allows you to drill thru the water channel (which is plugged by corrosion) about 5 inches or so, then it takes a little work to clear the passages thru the water nipples that are at 90 degrees with no straight path to them - you could pull the nipples off but I spent a little bit of time spraying WD40 and carb cleaner and continually blowing compressed air thru the nipples and after 15 minutes of this they opened up....
So after you clear the water passages in the cylinder head you will need to tap and plug the hole that you drill thru the factory solid aluminum plug - I used a 10-32 SST machine screw with teflon tape on the threads and a fiber washer.
The area that you drill thru the plugs is seperated from the area of the cylinder head parts(cam, rocker arms, valves) so the valve cover o-ring seals off the area where water could leak and get into the oil, plus the valve cover has a thru hole on the bottom left side as you look at it from the back of the motor - this thru hole is a tell-tale hole that would warn of a water leak.
Once I got on the right track it is a pretty simple fix that could be done in under a couple hours.

The Jelly Bean is now ready to fish -now that salmon season is about over.......

Thanks to all for help. Special thanks to rodbolt for expaining the water flow.
When rodbolt posts it is best to take note, Iv'e read many of your posts rodbolt and I can tell you have plenty of experience with the outboard engines.

Thanks again!

[rodbolt17]

I may have worked on an outboard once or twice, maybe a few sterndrives.

I usually pull the aluminium plugs and replace them.
I have a local machine shop make new ones and install them with Loctite 518.
occasionally the only recorse is to pull the head.

[backwoods]

I thought of that and may replace them down the road....I work at a very large machine shop and can make some up easily.

I am just glad to have this boat on the water for the rest of fishing season and I am now making a new list of boat do's for the off season.

I thank you again for your help.
As I said before I could tell from your posts that you had a good grasp of these engines.
I had a friend that was convincing me it was all water pump problem because he had a friend that does some boat mechanical work tell him the port at the base was directly from the water pump (then why was the water warm/hot when it did come out?????)if it was directly from the water pump.....

There can be alot of misinformation out there and one needs to discern for themselves what is logical and what makes sense - it takes alot of reading.....

Next time I'll start with a repair manual just so I have some visual.....

[rodbolt17]

I get it daily.
my ex wifes uncles cousin used to work on tractors and he said it was the muffler bearing.

and now he is right and I am wrong.