New member, water flow pilot hole problem

[KiwiPom]

Hey Solarman, did you have any luck in your search?

[Solarman]

dt55, peehole flow problem

My manual/ parts list doesn't show it. Lol. But I have seen mine on my motors, and read about how it works. Mine is located at the bottom of my cylinders, inside the water passages. When I removed my cylinder head cover to expose the water passages, it was a simple stainless spring with a stainless ball at the end, the ball covered a hole. the higher the water pressure the more the ball moved to open the hole to allow water out.

Unable to check browns point for the parts list there. But, I did read in another repair manual that the inline cylinder motors (2 stroke, yours and mine) had this pressure valve.
I know I have it, am almost certain you do, and believe yours is stuck open. I think a good flush with vinegar, or other solution for salt corrosion, for at least 15 - 30 mins might take care of the problem. Followed by a good water run/test at wot if able. Don't ignore overheating for anything.

Another thought kiwi. Are you just idling for the 15 mins while it stops flowing, our are you throttling up to about 2500 RPMs when it stops? Yes exhaust can interfere with water pump, but that means removing the foot again? If you do remove again let us know. Also, might check parts list to see if you have a sub-water pickup tube on your motor?
If the aluminum mating surfaces between the midsection and foot (where it bolts together) are corroded and allowing hot exhaust into the water chamber, it can cause problems.

Keep us posted. Sorry, I couldn't look your part up. But am sure you have this part.
Good luck.

[KiwiPom]

Thanks man, I appreciate your help and knowledge.
I noticed the problem while out on the water. Flow was quite good (but not exactly a torrent) so I decided to keep a close eye on it. Powering up on to the plane didn't seem to increase the flow as much as I expected although there was an increase. Over the following 15 minutes @4000+ rpm the flow very gradually decreased until it stopped altogether. It wasn't a sudden stop at all.
I decided to stop for 15 minutes while I threw my daughter overboard to test her new life jacket; on starting the motor again there was a small amount of flow from the telltale, but that stopped again within 5 mins.
At this point I decided to head back to shore. Put the boat back on the trailer and headed home. On the muffs about an hour later, things seemed to be back to where they were at the start, but I only ran the motor for about 5 minutes at idle.

I'm going to try the flushing first - the local distributor sells Rydlyme in 5 litre containers for $90 and advises me to use it undiluted. This means I'm going to have to be careful how I rig up the recirculating pump and return feed from the telltale and outlet to make sure I don't lose anything. I have considered the vinegar, but to be honest in the quantity I'd need I may as well go for the Rydlyme. Hopefully it will work faster than the rather more dilute vinegar.
Fingers crossed! I'll report back with an update.

[KiwiPom]

Oh, I also meant to say that I'll check all the mating surfaces for corrosion and fit. I'm too nervous to take the heads off as it's an older motor and I don't want to risk shearing any of the bolts. Hopefully the descale will do the trick.

[Solarman]

dt55, pee hole problems.

Think I would go with the vinegar, wouldn't need more than ten gallons in a large square trash can, or big square utility tub, deep as possible 2.5 feet. Could even build one around the foot with 3/8 plywood with a couple 2x4 squares, top & bottom for support, and put a couple large trash can plastic liner bags in it, to hold the water. Could probably build it, fill with 5 gals vinegar & the rest water, run for 20 mins adding make up water if need to keep heat down. Can do this two times for $60, or less? Then take it to the water and run it another 20 mins.
Don't run if overheat alarms start going off.
Good luck, keep us posted.

[KiwiPom]

Ok, so a quick update; I've sourced 5 litres of 100% Acetic acid for $40, which I can dilute down to 15 litres of 33%. I think this will be plenty strong enough for my needs, given that I will be removing the leg and circulating the solution around the system for 24 hours or so. I've also bought a submersible pump for $30 that is rated at 500 litres/hour @ 1.5 meters height - hopefully this will be enough. I'll rig the whole thing up in a 20 litre container with some plastic sheeting to return the exhaust/telltale flow back to the container.
I'll get to it this weekend and will post pics of the process.
Fingers crossed!

[Solarman]

dt55, pee hole problems

Not sure what that concentration will do to aluminum, and 24 hrs?? Are there directions for time and concentration for these materials in the system (aluminum passages, copper, brass, stainless steel)? Please be careful.
Keep us posted.

[KiwiPom]

Good point. I will be testing first to make sure that the acid doesn't have a negative effect on aluminum over that period of time. I have read that Acetic acid in any concentration has negligible effect, but I will be cautious.

[Solarman]

dt55, peehole problems

Thnx. Better safe than unhappy.

[KiwiPom]

Ok, so the lower leg is off, I've hooked up the pump to the water inlet tube, switched it on, and the water pumps out back through the leg exhaust. A tiny dribble comes out the rear exhaust port, but nothing is reaching up into the head so nothing out the tell tale either. I've taken the thermostat out to check.

Question: I was thinking that the water inlet tube channelled water up and around the head before it went back down around the exhaust jacket. Am I wrong? Does the water flow split before it reaches the head and some is directed straight back down the exhaust jacket?
If this is the case I'm going to need a much bigger pump!

[KiwiPom]

Looking at the service manual it looks like there's a divert at the top of the inlet tube that channels part of the flow back out through the exhaust jacket. Damn.
So... I'll try and find something to block this, forcing the solution through the head. If this doesn't work I'll have to reassemble the leg and run the whole thing in a barrel, which will mean having to use a much more dilute acid mix, probably 15% instead of 33%.

[Solarman]

dt55, mid 90, water flow problem

Might try connecting your garden hose directly to water tube to see if it makes the complete path. That should tell you if the pump is the problem? If the water hose does the same thing, It could mean that you have some problems in the water channels/ passages going into the powerhead (at the top of the midsection, under the powerhead)?
Let us know what you find out. If you have a manual I think I remember a water flow diagram in the front of mine. Ill try to find mine tomorrow and look.

[KiwiPom]

Looks like it's just a pressure thing. Garden hose was fine. I ended up cutting a piece of ply to cover the bottom of the leg where the exhaust exits, which I've tied in place with a bit of rope. It's not a perfect fit so some acid mixture still exits here, but it provides enough back pressure to force the rest of the mix up through the head.
It's now been about 2 hours since I started. The mixture is looking extremely dark and dirty. Fingers crossed!

[KiwiPom]

Well... that was interesting, and somewhat of a learning curve.
It certainly looks to have cleared out a lot of junk from the cooling passages - about 2 cups of sediment and crud were left over at the bottom of the container once I had finished. I was able to idle in a large bin filled with water for about 25 minutes without the flow from the telltale stopping which was a good sign, plus the head remained warm to the touch, no signs of overheating.
But...
The flow from the telltale doesn't seem particularly stronger than before and doesn't seem to improve much when revving the motor. It's definitely weaker than most outboards that I see at the boat ramp. Something still doesn't seem right.

Having established that the flow from the pump is split before getting to the head, I noticed that the bottom of the exhaust cooling jacket (inside the leg) was essentially a giant rubber grommet surrounding the exhaust pipe and seemingly pressed into place. This has a single "pee hole" in it that restricts the water outlet, allowing the jacket to fill with water from the pump feed at the top.
This rubber grommet has clearly shrunk or perished due to age, letting the water from the pump flow not only out of the hole in the grommet, but at each of the four outer corners. I suspect that this is allowing far too much water to be diverted away from the head and straight out of the exhaust cooling jacket. In turn this would reduce the available pressure to pump water upwards and on to the cylinder head.

Purely theorising, but ff this piece of rubber allowed more water to pass through as it warmed up, this would explain why the flow from the telltale gets progressively weaker over 15 minutes...

Phew. I hope that made sense! I tried to take photos but it was a dark leg, covered in dark oil and with a black rubber grommet. Even with a flashlight I couldn't get a decent pic.

So, next step is to take it out on the water next weekend and see what happens. In the meantime I will ask my local Suzuki guy if he knows how to remove/replace the grommet. Maybe it's a known issue with these.

So there's my update, if you're still awake.

Thoughts? Am I on the right track with the water jacket outlet?

Cheers.

[Solarman]

dt55, mid 90s, pee hole flow.

You lost me? I can't tell what you're referring to? A rubber grommet in the exhaust? There might be rubber grommets in the lower unit, but I can't think of any in the midsection/ drive shaft housing, unless its the exhaust port on the back of the midsection housing? Any rubber in the main exhaust chamber would probably burn if close to the powerhead? Can you find it in the parts listing?

Yes, I think you should give it a good run since flushing. To see if you still have problems.
Good luck and post us on what happens.