water impeller on Honda 20hp

[Jason F-18]

So I did the annual oil & filter change and changed out the spark plugs on my 20 HP Honda outboard. Everything is back together and ran it in a tub of water to warm it up. There is no water coming from the cooler. Last time I ran it on the lake (2 months ago) it was flowing just fine. There is nothing blocking the intake and the water in the tub is about the exhaust holes. So I have no idea why it would stop flowing now.

How big of a project is it to replace the impeller on these small 4 strokes?

If I took it to a mechanic, about how much will they charge?

 

[wrechin2]

My labor guide says .8 which is less than a hour. Depends on shop rates and if they go by the book. Pump is around $22.

NOT a HONDA MAN........BUT...Try running it on a flush adapter and see if water is coming out around the prop. Some engines (most merc V-6's) don't expell water untill they warm up and some (OMC's AKA Johnson and Evinrude) pee almost as soon as they start. If there is water running out around the prop after say 20 seconds of running, then it is moving water. If it is not you may run into a situation where the pump has come apart and the little pieces are in the engine and will need to be found or you risk overheating the engine due to blockages and that will burn up the engine, if it hadn't already. Compression AND leak down test will tell ya. Had 2 this year for that and both had overheat damage.

just my thoghts.........

 

[Jason F-18]

Hopefully it hasn't overheated. I only ran it for about a min waiting for it to pee, then shut it down.

 

[wrechin2]

Tyr the flush tool..If there is water coming out around the prop it is moving water. Not familiar with which way they pee...Instant or after the t-stats open up.

 

[Jason F-18]

Just got home with an ear muff flusher. Put water to it and it sprays from under the cups, very little coming from the prop. I can push the cup tighter and get some water to come out of the pee tube, but still no flow when I start the motor.

I'm not sure if it was ever replaced. the motor is a 2005. I have had it for about a year and put about 30 hours on it. My father-in-law only had for about 5 months before giving it to me, but he only ran it once i believe.

What will it take for me to replace the impeller? Parts and any special tools?

I have found the impeller kit that has the impeller, o-ring, and gasket. Is this all I should need?

 

[wrechin2]

Couldn't tell ya on the linkage how it disconnects. Never touched a Honda. Most jap engines have a turn buckle type linkage. I don't know about the special tools. Best be would be look on ebay for a manual and it should tell you step by step how to replace. JMO...

 

[Jason F-18]

Ok, I have the manual now. Still need to order the impeller kit and will try replacing myself.
One thing: I just had the thought to remove the intake screens just to check. When I did there were several small pieces of black rubber which I would assume is from a failed impeller.

My question is: what other damage could the pieces have cause dand what do I need to do to make sure that I get them all Out of the system when I change the impeller?

 

[wrechin2]

Need to account for all the pieces.........If the impeller failed due to lack of water then the pieces should be low and ok. If failed with water, then the pieces can be lurking in the engine and stop up the cooling passage and burn the engine. You have a 50/50 chance.

 

[Jason F-18]

How do you know when you got them all? emoScratch do i need to try to put them back together like a puzzle? Is there any way to flow water in reverse to try to push them out of the intake with the screens off?

 

[wrechin2]

Yes, it is puzzle time. I couldn't tell you if you can reverse flush it as I have never laid hands on a 4 stroke and unaware of how the cooling system flows throught the block. With the pieces being in the screen, I would say that it was a failure due to lack of water and that is why they are low. If it failed with water, the pieces would be in the engine as they would have been forced there from water flowing into the engine and got moved as they broke off. See how much you can account for.......

 

[Jason F-18]

OK, I'm waitng on the impeller kit to get here. Will let you know what I find once in there. Is there anything else I should plan to service/ replace while I have the foot off?

 

[wrechin2]

Not really...

 

[Jason F-18]

I the foot taken off and the water pump opened up. Here are some pictures of what I found.

I also ordered the water flush adapter that screws into the thermostat cover. I am going to take out the thermostat, and then flush the engine from the top down. I am hoping this should get the rest of the plastic pieces out of the cooling system.

Any reccomendations on gear oil the it easy to ind around here? The manual says type 90 Hypoid Oil. Also, the manual calls for marine grease. Can any type of automotiv grease be substituted? I would like to try to get everything back together in the next couple of days and don't want to have to order something if I don't have to.

Thanks,

 

[Bubbakat]

Use a good synethic marine oil in that lower unit. While you have it down be a good time to pull the prop and check for fishing line and put just a film of grease on the prop shaft to insure it doesn't seize before next time. Sorry to jump in but I thought I would throw that out there.

 

[wrechin2]

Those are some good points !!! emoToast

 

[Jason F-18]

Yeah, I pulled the prop assembly. I plan on giving everything a good grease down. Any recs on where to get marine oil and lube in the hixson soddy area?