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Weak pee stream even after changing impeller. What else to check?

mitchbuck

Contributing Member
I have a 21ft Seacat with twin Honda 50s and blew a powerhead last season so I purchased a used ~2002 Honda 50hp this winter. This outboard had a weak pee stream and the previous owner said it needed a new impeller. So I changed the gaskets and impeller, which was in terrible shape, and the thermostat as well, but didn't see to get much of an increase in the pee stream. The engine gets very warm compared to the other engine and my concern is overheating. I poked some heavy fishing line up pee hole and not much came out. My concern is that chunks of the impeller made its water up into the water jacket and are clogging water flow. Does anyone have any ideas for where the water could be either getting blocked and escaping? Could there be a bad seal between pump and waterline and should I change the entire pump housing out? If I drop the lower unit and I hook a garden hose up to water line and try to flush crap out? I really don't want to have to rip the head off to rip the head off if I don't have too....

Thanks
 
So after searching more on this site is seems that I can backflush engine through the thermostat port if I remove the lower unit. I'll give that a try.
 
Probably sediment in hose leading to peehole. Try putting a coathanger or other wire into the hole to see if it improves. If so, take the hose off and replace.
 
Yes, backflush through the tstat housing with lower end off. But, replace the entire pump too. You cannot get 100% pump performance if the housing is worn, even a little bit.

Did you find any of the missing impeller pieces? They mostly fall out the bottom of the housing so when you have the pump off you can remove an intake screen and try to find them.

Also, don't just weed line the tell tale. Take off the little hose and make sure it is soft and pliable. It should be replaced every two or three years. Take the fitting it goes on out of the block. Then, when you have everything back together, run the engine with the fitting off. If there's anything in there. It will likely blow out the first second or so. When you go to put the side cover back on, make sure that you properly route the hose up through the hole in the splash tray so that it isn't pinched between the tray and cover. Very common error.

Good luck.
 
Get a gallon of salt-away and fill a barrel of water then run the engines for around 1/2 hour in the barrel with the salt-away in it. Were you able to determine why the other engine got cooked? Keep an eye on the spark plugs if they are a powdery white your running too lean the insulators for the electrodes need to be a nice toasty brown. Service the fuel system starting at the fuel tank pickup tube make sure it is clear and the antisiphon device is in good condition. Replace all the fuel lines up to and inside the engines. If in doubt just replace the antisiphon valve. Assuming your running a in hull fuel tank? You dont want to cook another engine with a existing condition.
 
Has a compression test been run on the warmer engine. Was water tube checked for an obstructions,impeller pieces?
 
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Thanks for all of the input. So I took off the pee hole tubing, straightened it out, and pushed heavy fishing line though and dislodged some bits of old impeller! Now she pees like a champ! But I am going to run the engine with a bunch of saltaway and then drop lower and flush out of the thermostat as recommended because I'm sure were there was some there is more hiding. Unfortunately the weather was bad this weekend and I wasn't able to get out on the water to see if it gets warm.
 
Update. So I ended dropping the lower unit and backflushing through the thermostat port and some sand, grit, and some bits of impeller were found in the bucket I placed underneath it. Ran the boat this weekend and had a good stream so hopefully I flushed most of the junk out. I'm going to keep an eye on it though. Thanks for everyone's help on here!
 
Yes, backflush through the tstat housing with lower end off. But, replace the entire pump too. You cannot get 100% pump performance if the housing is worn, even a little bit.

Did you find any of the missing impeller pieces? They mostly fall out the bottom of the housing so when you have the pump off you can remove an intake screen and try to find them.

Also, don't just weed line the tell tale. Take off the little hose and make sure it is soft and pliable. It should be replaced every two or three years. Take the fitting it goes on out of the block. Then, when you have everything back together, run the engine with the fitting off. If there's anything in there. It will likely blow out the first second or so. When you go to put the side cover back on, make sure that you properly route the hose up through the hole in the splash tray so that it isn't pinched between the tray and cover. Very common error.

Good luck.

So I had a great stream for almost two months after backflushing it twice and thoroughly cleaning/probing the telltale with weed wacker line. Recently the stream weakened again. After probing with line didn't fix it, I ended up taking the fitting off. It was clogged with a a lot of sediment inside the nozzle. I put it back on to test and it has a great stream now, but I am wondering if I need any thread locker or anything to secure the fitting in place? I ask because there looks to be some kind of putty on there. Thanks!
 
I don't think it should need any thread locker to keep it from backing off as long as you SNUG it down well. But, if you are worried about it, a drop of LocTite shouldn't hurt a thing.

I emphasize SNUG because tightening the fitting too much can actually cause the block to crack. While not an "engine killer" mistake, you just don't want THAT!
 
Update. I was successfully able to remove the fitting with a 10mm socket and found a bunch of sand wedged inside the nozzle that i was able to clean out. I cleaned up the threads and put the fitting back on and it runs great now. I was concerned that I might strip the block but I did not thankfully.
 
Good deal! Thank you for reporting that and adding credence to the need for taking that nozzle out and cleaning behind it.

GOODONYA!
 
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