dannyx5321
Recruit
- Joined
- Sep 16, 2008
- Messages
- 5
Hello everybody,
I have been lurking and learning on this fine forum, and so far I have been able to understand and fix my I/O Mercruiser problems.
Here is the story:
I have an I/O 1975 (1976?) Mercruiser with a 351W Ford engine FWC and a Mercruiser I (pre-alpha) leg installed in an 18 ft. Beachcraft runabout fiberglass hull. Serial Number of the engine is 4466149, and the sterndrive is the 233 model with a 1.32 ratio gears in it.
I have rebuilt the engine and the drive myself in the course of a few months, and I believe I have done it right; or so I thought up until after using the boat for about four times some problems started to occur.
The first and the most important issue is the cooling problem. After I disconnected the raw water hose, the one connecting the transom bracket pipe with the heat exchanger, I saw that no water would come out of the pipe sticking out of the transom bracket.
I have dismantled the lower unit, and inspected the impeller, housing, gaskets, tubes, seals, grommets, etc, and I concluded that all looked right.
I installed everything back together but before reassembling the lower unit, I wanted to visually see the impeller pumping water.
After installing the flush attachment I ran water through the leg, and spun the propeller by hand as fast as I could while the lower unit was in forward gear. And here is the strange thing:
NO WATER CAME OUT,
not one single drop. I forgot to mention that I installed the copper pipe in the impeller housing before doing this test.
Puzzled, I poured some water through the copper pipe in the impeller housing in an attempt to prime the pump. When I spun the prop again, the water was drawn in, instead of being pumped up!
At this point I pulled the impeller out of it's housing and installed it again while a friend of mine was slowly rotating the prop (with the unit in gear of course), only to make sure that the fins of the prop are all properly oriented, but it didn't help a bit.
Thinking that my manual spinning was too slow, I installed the lower unit back and launched to boat, but still, no single drop will come out at the transom bracket. One more thing: before installing the lower unit, I took the garden hose and plugged in into the copper pipe (now fitted in the upper unit), and I could see a full stream of water coming out of the transom bracket pipe.
Three times I removed the lower unit thinking that I did not properly aligned the impeller housing copper pipe and the upper unit. I have used silicone spray at the pipe and at the grommets/seals in order to ease the installation.
Everything proved futile.
My conclusions so far:
1. The pipe between the impeller housing and the upper unit is not properly fitted.
This thought is reinforced by the fact that I discarded the alignment/spacer PVC tube that used to sit around the copper pipe and (I assume) provide some guide/alignment at mating the lower unit with the upper one. I chucked that tube out because it became distorted at the lower end, I presume due to overheating.
2. The propeller is not in fact being turned by the drive/engine.
This thought is absurd because I can run the boat, but still it ran through my mind.
Any thoughts from people will be appreciated, and I will keep you updated as I plan to regroup and do some more thought pondering and wrenching pretty soon this week.
Thank you and congratulation to those who have managed to read all the way down through my long rant
Danny.
I have been lurking and learning on this fine forum, and so far I have been able to understand and fix my I/O Mercruiser problems.
Here is the story:
I have an I/O 1975 (1976?) Mercruiser with a 351W Ford engine FWC and a Mercruiser I (pre-alpha) leg installed in an 18 ft. Beachcraft runabout fiberglass hull. Serial Number of the engine is 4466149, and the sterndrive is the 233 model with a 1.32 ratio gears in it.
I have rebuilt the engine and the drive myself in the course of a few months, and I believe I have done it right; or so I thought up until after using the boat for about four times some problems started to occur.
The first and the most important issue is the cooling problem. After I disconnected the raw water hose, the one connecting the transom bracket pipe with the heat exchanger, I saw that no water would come out of the pipe sticking out of the transom bracket.
I have dismantled the lower unit, and inspected the impeller, housing, gaskets, tubes, seals, grommets, etc, and I concluded that all looked right.
I installed everything back together but before reassembling the lower unit, I wanted to visually see the impeller pumping water.
After installing the flush attachment I ran water through the leg, and spun the propeller by hand as fast as I could while the lower unit was in forward gear. And here is the strange thing:
NO WATER CAME OUT,
not one single drop. I forgot to mention that I installed the copper pipe in the impeller housing before doing this test.
Puzzled, I poured some water through the copper pipe in the impeller housing in an attempt to prime the pump. When I spun the prop again, the water was drawn in, instead of being pumped up!
At this point I pulled the impeller out of it's housing and installed it again while a friend of mine was slowly rotating the prop (with the unit in gear of course), only to make sure that the fins of the prop are all properly oriented, but it didn't help a bit.
Thinking that my manual spinning was too slow, I installed the lower unit back and launched to boat, but still, no single drop will come out at the transom bracket. One more thing: before installing the lower unit, I took the garden hose and plugged in into the copper pipe (now fitted in the upper unit), and I could see a full stream of water coming out of the transom bracket pipe.
Three times I removed the lower unit thinking that I did not properly aligned the impeller housing copper pipe and the upper unit. I have used silicone spray at the pipe and at the grommets/seals in order to ease the installation.
Everything proved futile.
My conclusions so far:
1. The pipe between the impeller housing and the upper unit is not properly fitted.
This thought is reinforced by the fact that I discarded the alignment/spacer PVC tube that used to sit around the copper pipe and (I assume) provide some guide/alignment at mating the lower unit with the upper one. I chucked that tube out because it became distorted at the lower end, I presume due to overheating.
2. The propeller is not in fact being turned by the drive/engine.
This thought is absurd because I can run the boat, but still it ran through my mind.
Any thoughts from people will be appreciated, and I will keep you updated as I plan to regroup and do some more thought pondering and wrenching pretty soon this week.
Thank you and congratulation to those who have managed to read all the way down through my long rant
Danny.
