I have a 1997 Sea-Doo GTI that I got about a year ago I bought it with a seized up jet pump, knowing it would be an easy fix. However, the ski keeps trashing jet pumps I’ve rebuilt 2 so far and now on my third. It seems to me the bearings are getting too hot and melting the plastic nose cone causes debris and water to get in the jet pump bearings, I’ve used the oem jet pump oil and Lucas oil that was equivalent. I’m wondering if the alignment of the engine has anything to do with it but I want to get others input who might have more experience before I have to buy the alignment tool or try and make one. And if the alignment is not the problem then an idea on what’s causing these jet pump failures.
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1997 seadoo gti keeps trashing jet pumps
- Thread starter Austin04
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Is your motor alignment correct?
Too much THRUST load on the pump. Install the pump with one rubber bumper on the drive shaft and check "end play." remove the waterseal and bellows for the check so you'll have room and you can see better. Also the drive shaft will move easier. If you can't pull the shaft back and forth1/4" the extra rubber bumper is butting too much load on the thrust bearing in the pump. Friction =heat... stuff gets melted. I'd also check the drive shaft for being bent as @tobytd suggested. If you have the means to align the engine I'd slap that on there for a check as well. I think you're problem is gonna be "thrust load." Good Luck.
I'll tell you something else that happens, if you install the pump shaft with the pump horizontal the bearing plate for the thrust bearing can come out of that fit and get cockeyed. You have to keep pressure on that shaft while assembling or assemble it vertically. I am very careful with that damn thing. LOL Vertical is less likely to cause problems
What oil are you using? I use Mobile One sythetic gear oil I think it is 75W-90. I haven't looked in a while. Ha ha. I get a quart for $12 and I do a lot of pumps so it's cheaper for me. Good Luck.
I'll tell you something else that happens, if you install the pump shaft with the pump horizontal the bearing plate for the thrust bearing can come out of that fit and get cockeyed. You have to keep pressure on that shaft while assembling or assemble it vertically. I am very careful with that damn thing. LOL Vertical is less likely to cause problems
What oil are you using? I use Mobile One sythetic gear oil I think it is 75W-90. I haven't looked in a while. Ha ha. I get a quart for $12 and I do a lot of pumps so it's cheaper for me. Good Luck.
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Spider4real
Active Member
All I can say is I had a misaligned engine and the result was it wore down the splines on the driveshaft at the PTO end. The PTO splines were also damaged and I had to replace both parts. My pump and impeller survived undamaged.
Now this will be controversial, but I made an alignment tool that I found on this site. 2 years later and still going strong. I inspected the drive shaft several times and so far zero wear detected. I also just made my own shims out of a sheet of aluminum from Home Depot.
I see as I was writing this etemplet probably just gave you the real root cause. I would be interested in hearing the resolution to this problem.
Cheers
Now this will be controversial, but I made an alignment tool that I found on this site. 2 years later and still going strong. I inspected the drive shaft several times and so far zero wear detected. I also just made my own shims out of a sheet of aluminum from Home Depot.
I see as I was writing this etemplet probably just gave you the real root cause. I would be interested in hearing the resolution to this problem.
Cheers
I had a guy bring me a 1996/97 GTI. ALL of the engine mounts the rubber separated. Sumbish was so misaligned it was unbelievable. Whole engine rattled. I rebuilt the carbs and lined it up spot on... checked everything of course. Ower is a car mechanic and it is his son's ski. I told him. This thing is gonna come apart but ride it till it blows. The following summer he called me and told me the carb bolts were loose. I laughed and said, gotta be a whole bunch of stuff loose the way that engine is vibrating. Told him to keep an eye on things and check exhaust bolts for sure. 3 years later they are still riding that thing !!! LOL Go figure. When I pull a pump I check alignment.
95% are a good bit out of alignment.I think this was the engine. LOL My align bar is in position and.... it ain't slidin in there.
Spider4real
Active Member
Lol...that's crazy. I always figured there are tolerances built in that are acceptable. But then you hear stories like this that beat all expectations and make these machines sound unbreakable.
I will just assume this is one of those 1 in a million cases of a seadoo that just doesn't know it was supposed to fall apart and head to Seadoo heaven.
On another note, my engine was off about the same amount as in your picture and that caused the splines to strip. I was lucky to have caught it when I did because I figured ones more outing and it would have started to slip and leave me stranded. There were almost no splines left and tons of play.
I will just assume this is one of those 1 in a million cases of a seadoo that just doesn't know it was supposed to fall apart and head to Seadoo heaven.
On another note, my engine was off about the same amount as in your picture and that caused the splines to strip. I was lucky to have caught it when I did because I figured ones more outing and it would have started to slip and leave me stranded. There were almost no splines left and tons of play.
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