Outdrive Impeller

[E10Critchy]

Ok guys I have a Chevy 350 and an Alpha 1 outdrive. I was at the river. Went from the bottom of havasu up to topoc. Once I waas near the sandbar, the boat RPM's went up then they stabalized a little higher and the boat slowed down. So now the RPM's are holding but the boat slowing down. I stop check the fluid level in the outdrive which is ok. I check a few other things. Now I start it up and it works again. Almost like it heated up the outdrive and then by sitting it cooled down enough to work. I took it easy the rest of the day and had no problems . Now is this a busted outdrive impeller or partially broken impeller, or something else. By the way I towed a very heavy boat the day before. Don't k now if related to problem or not). Thanks for any help.

[Ryan00TJ]

The impeller only supplies the engine with water to cool the motor. If the engine is not overheating and running fine at temp there is no impeller problem. The fact that your not increasing speed with added engine rpm leads me to suspect a spun engine coupler. How hard were you towing the other rig?

[BDMar]

I would guess either the coupler is going bad or the propeller hub

[E10Critchy]

Ok sounds like it isn't the impeller then cause my temp was fine the whole time. The boat I was towing was like a 22 ft sea ray but I noticed at the end of the tow it was tied off on the cleat on his boat so it was pulling it down and my boat was full throttle towing him at about 15 MPH and I have a 350. By the way when I had the problem the next day when I would shut down the moter it was dieseling, like when you shut off the key but the motor continues to run. It did this twice. And when the RPM"s went up, after a minute the RPM's stayed the same but the boat slowed down till it eventually stopped even though the RPM's were still up. I noticed some smoke just above the outdrive, but didn't notice any in the engine compartment. Thanks again for any help.

[ToMorrow44]

Maybe it's just me but why were you towing somebody at full throttle and 15mph? Seems a little excessive and probably the root of your problems. I'd be going through checking everything after a tow like that.
-Tom

[watergun4u]

From your info, I would be more then likey to tell you that you 1, spun the prop, or 2, the cupler went south, You should never tow someone at full throttle, 5,to 8, max what you did put way to much presure on the cupler and the hub on the prop, check both, I am sure it's one or the other!!!!!!!!!:eek: :eek: :eek:

[BDMar]

Maybe it's just me but why were you towing somebody at full throttle and 15mph? Seems a little excessive and probably the root of your problems. I'd be going through checking everything after a tow like that.
-Tom
From your info, I would be more then likey to tell you that you 1, spun the prop, or 2, the cupler went south, You should never tow someone at full throttle, 5,to 8, max what you did put way to much presure on the cupler and the hub on the prop, check both, I am sure it's one or the other!!!!!!!!!:eek: :eek: :eek:
I agree with both of these. Also, if your engine was "running on" when you shut it down 90% of the time this means is was hot. If the smoke was outside the boat I am betting you smoked your prop hub.

[E10Critchy]

I was at full throttle on the boat because otherwise I was barely moving. Lesson learned don't tow anybody anymore, just give them a ride to there truck and trailer. As far as the motor being hot the temp was reading normal about 160. By the way this incident was the day after I did the tow. I pulled off my prop and looked inside it. I didn't see anything obviouse. What should I be looking for at the hub. I also put the boat in gear and turned the prop by hand. When I did this the pulleys moved so the motor turns over. If I spun a hub would the motor still turn over.

[E10Critchy]

Ok I took the boat to the lake to test it under a load. I took a black marker and marked a line on the hub with the prop. I tested it under a load. I pulled the prop and the line was off. So I guess it's a spun hub. Thanks everybodcy for your help I appreciate it.

[watergun4u]

:D there are dots, on the bottom side of the prop,one on the propmetal, and one on the hub, if they are not inline, then the hub is spun, and you need to have it repaired, or buy a new one!, If you spun the hub, you should see a bunch of grease on the shaft coming in through the transom, as well as you will smell burn rubber, , if you dont see anything wrong from there, take it to the lake and see what happens, Start to go, out side the 5 mile zone, and start to get up on plane, and have someone, with motor smarts and watch the hub, if it is spinning fast and the boat is going nowhere, the the cupler is shot!just my .02

[HitIt]

How long were you tugging at full throttle?

[BDMar]

:D have someone, with motor smarts and watch the hub
Just curious... how do you watch the hub when the prop is under water, spinning, thrusting aireated water? Scuba gear??:D

[watergun4u]

Just curious... how do you watch the hub when the prop is under water, spinning, thrusting aireated water? Scuba gear??:D
my bad I meant the cupler , and the shaft coming through the transom on the inside of the boat!:D

[BDMar]

my bad I meant the cupler , and the shaft coming through the transom on the inside of the boat!:D
Thats what I figured you meant!:D :D