Thread: Does this sound normal?
09-25-2009, 12:57 PM #1
Does this sound normal?
Does this enigne sound about right? I'm new to two-strokes and jet skis, so I need some input.
09-25-2009, 02:57 PM #2
It sounds more or less normal for a 587/657/717 family of engine. There is a bit of rattle there at idle and it sounds a bit boggy when the throttle is blipped but that could just be the recording.
They do kind of have a rattle sound to them, though. They also sound different on the trailer since there is no load on the engine. Normally, if there is something wrong with a crank or wrist pin bearing it is quite obvious, and dramatic.
Have you done a compression check?
If the comp is good (you are looking for it to be within 10% on the two cylinders and depending on the engine somewhere in the 130 area, though do not get too wound up if it is lower as long as they are even) and it runs well on the water it is probably fine.
09-25-2009, 03:21 PM #3
I did check the compression and if I remember right it was around 110 or so. That seemed a little low to me, but both cylinder were almost exactly the same. Being that both cylinders are the same, I wasn't to worried about it. That engine has sat for quite a while, so I've been a little skeptical of it. I've drained that old gas (it looked like apple juice), drained the oil and changed the pump oil. I've got Lucas semi-synthetic 2-stroke oil in it now. It's supposed to be pretty good stuff.
09-25-2009, 11:04 PM #4
You can run mineral oil in that engine as long as it is AP-TCI and not TW-3.
I would run a can of fogging oil into it too just for craps and giggles. When one sits for that long (even if it was fogged) they can get some rust on the bearings. If you can give it a good lube before trying to use it you should have a better chance of avoiding any unpleasentness.
The good news is that those engines seem to weather this kind thing more or less ok. The comp may come up with use, or go down, depending on how much rust, if any, was on the cylinder walls. If the bearings did not get any serious rust she should be ok.
I would suggest pulling the carb/carbs off and cleaning/rebuilding them. Based on what the fuel in the tank looked like, how do you think the carbs look. It would be a shame for it to survive sitting up all that time just to die from a fuel delivery problem.
09-25-2009, 11:19 PM #5
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It's really tough to judge the "proper" sound of a videotaped PWC. I've recorded some myself, and I don't think you can accurately tell anything in a recording.
The main problem is that the pumps rattle a lot (even at idle in water), so it is hard to tell if it is the engine or pump, especially on a recording. The are two main "bad" engine sounds to watch for, crank/rod bearings (knock/grind/whirring), and piston slap.
09-26-2009, 04:41 PM #6
you ask if it "sounds about right"
Now go run it easy at first and see how it runs..
09-26-2009, 11:22 PM #7
Well, I got it out and rode it a little. Seemed like it run really good. It started up pretty quick and sounded good on the water. I took it out in a farm pond at my parent's house, so I didn't have room to really run it hard. I had just enough room to get it up on plane and turn before I hit the bank! I'm gonna start another thread with pics. I left the pics on my parent's computer so it might be a few days.
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