I am wondering if you guys with some experience with these crafts can help a new guy out or point me in the right direction.
Here is the story:
I recently purchased a 1996 challenger. On the test ride which lasted about 30-45 min the boat performed great. It would stop, start, accelerate great and the engine had about 155 PSI compression on both cylinders. On the day we tested the boat the air temp was about 45 degrees and the water was maybe that (Lake Michigan).
I took the boat home. It sat for a few weeks before we could get it out again. This time the boat performed great and we ran it for about an hour with no issues. Air temps in the sixties and I don’t know the water temps.
The second time I took the boat out it was warmer and the water temp was also warmer on an inland lake. For the first 20 min or so the boat was working great. The weather took a turn for the worst so we headed in. After letting the boat idle for 3-5 min on the water before we headed back in. I noticed that at this point I would need about 3/4 throttle to get the boat to maybe 20mph and it was hard to get it to come on plane. It didn’t sound like it was pump cavitation but It must have been? It was moving through the water fine but idle speeds required about half throttle.
I got the boat home flushed it out check everything that I could and didn’t notice any weeds or any other obvious issues. I was unable to see daylight past the impellor / wear ring.
This gets me to last night.
We take the boat out. Right out of the gate it works just fine. After about 5 minutes it turns into a dog. High RPMs and no speed and now it sounds like it is was pump cavitation. You could go across the lake and feel the boat slow down and take off again with no throttle input change. I crawled under the boat in the lake and found some weeds in the intake. I pulled them out and it made no impact to the boats performance.
We tooled around for a while but was never really able to get it on a plane and up and moving.
We stopped for about 20 min to play in the lake. Start it back up and take off. Ran great, I could accelerate as expected and I could go 50 or so.
Then I show down and try to accelerate again and boom back into dog mode, RPM spike and no acceleration. Sounds and feels like cavitation. I stop the boat and check for weeds. Noting, but when I put my hand in the rear discharge it was warm, bath water warm. The engine was off and I had my hand / finger in the grate and in the rear discharge housing. I was expecting it to be closer to lake temp rather than warm.
We headed back in for the night and I wanted to research the problem more. One last time I tried to accelerate, and it took off and came on plane just fine.
When I bought the boat the guy informed me that last fall he had the wear ring and impellor replaced.
So here is my question:
Do I have an air leak somewhere that is causing pump cavitation? If so where do I start to look?
Is this pump cavitation or something else?
I so not see daylight between the impellor and the wear ring. Is there a way to check clearance without pulling it all apart?
I see no major damage on the impellor, could it just be worn?
Sorry for the long story but I thought I would try and give you the story behind what I am seeing to aid you in a response.
Thank you for taking the time to read and respond.
Brian
Here is the story:
I recently purchased a 1996 challenger. On the test ride which lasted about 30-45 min the boat performed great. It would stop, start, accelerate great and the engine had about 155 PSI compression on both cylinders. On the day we tested the boat the air temp was about 45 degrees and the water was maybe that (Lake Michigan).
I took the boat home. It sat for a few weeks before we could get it out again. This time the boat performed great and we ran it for about an hour with no issues. Air temps in the sixties and I don’t know the water temps.
The second time I took the boat out it was warmer and the water temp was also warmer on an inland lake. For the first 20 min or so the boat was working great. The weather took a turn for the worst so we headed in. After letting the boat idle for 3-5 min on the water before we headed back in. I noticed that at this point I would need about 3/4 throttle to get the boat to maybe 20mph and it was hard to get it to come on plane. It didn’t sound like it was pump cavitation but It must have been? It was moving through the water fine but idle speeds required about half throttle.
I got the boat home flushed it out check everything that I could and didn’t notice any weeds or any other obvious issues. I was unable to see daylight past the impellor / wear ring.
This gets me to last night.
We take the boat out. Right out of the gate it works just fine. After about 5 minutes it turns into a dog. High RPMs and no speed and now it sounds like it is was pump cavitation. You could go across the lake and feel the boat slow down and take off again with no throttle input change. I crawled under the boat in the lake and found some weeds in the intake. I pulled them out and it made no impact to the boats performance.
We tooled around for a while but was never really able to get it on a plane and up and moving.
We stopped for about 20 min to play in the lake. Start it back up and take off. Ran great, I could accelerate as expected and I could go 50 or so.
Then I show down and try to accelerate again and boom back into dog mode, RPM spike and no acceleration. Sounds and feels like cavitation. I stop the boat and check for weeds. Noting, but when I put my hand in the rear discharge it was warm, bath water warm. The engine was off and I had my hand / finger in the grate and in the rear discharge housing. I was expecting it to be closer to lake temp rather than warm.
We headed back in for the night and I wanted to research the problem more. One last time I tried to accelerate, and it took off and came on plane just fine.
When I bought the boat the guy informed me that last fall he had the wear ring and impellor replaced.
So here is my question:
Do I have an air leak somewhere that is causing pump cavitation? If so where do I start to look?
Is this pump cavitation or something else?
I so not see daylight between the impellor and the wear ring. Is there a way to check clearance without pulling it all apart?
I see no major damage on the impellor, could it just be worn?
Sorry for the long story but I thought I would try and give you the story behind what I am seeing to aid you in a response.
Thank you for taking the time to read and respond.
Brian
