09-28-2007, 06:17 PM #1
What the heck is this noise!??! PART 2!
Ok, the last thread on this subject was gettin a bit long... thought id start off a new one about the issue.... Old thread is here is in case anyone wanted to read what all had been done and what not:
FINALLY got my SLX out today after replacing the impellar/pump/etc......
Water was REALLY rough, pretty windy on the lake today, not the greatest day for a test, but it worked out nontheless...... Ran it for nearly 4 hours..... Heres what I noticed, and found out...
1. As soon as I hit the throttle, I noticed the major vibrating noise from the rear end was no longer present, thanks to the new impellar, bearings, etc etc..... That was a good sign...
2. I DID however still have an odd low vibrating sound coming from the engine area itself. Doenst do it at all when idling... but only when you give it gas, as the ski is gettin up out of the water. After about the first hour for riding, it seemed to get better. Not sure how else to describe it, other than a low tone, mild vibrating sound... DEFINATLEY coming from the engine area. It didnt seem to be at all major, and for all I know might be perfectly normal. The jet ski did run near perfect, so who knows. Any ideas on that? The rubber driveshaft bumper on the engine end is worn nearly off, the new one from Atlantic Motor Sports came today, ill be putting that on tomorrow... Any chance the noise is related? Might be absoultey normal and I just never noticed it before, who knows...
3. After riding for the first 15 minutes... I came back to some shallow water, cut the engine off and felt how hot the cylinder and cooling rail were... they were QUITE hot... which worried me.... Rode it for about 30 more minutes nonstop and came back and checked again... I expected them to be bascially on fire, but to my surprise were quite cool. Guessing the thermostat works right after all?! My question on that is... at what temp is the thermostat supposed to allow more water in? And should it be that hot, that fast?
4. Steering Issue... while in the down time waiting to replace the impellar and stuff, I realigned the steering which was WAY off from the previous owner.... Even though after I redjusted the cable, the handlebars and jet nozzle are perfectly square out of the water, WHEN in the water... it STILL pulls kinda badly to the left.... Its annoying to try to go straight while keeping the steering slightly to the right!!!!!!
5. I GOTTA replace my thumb throttle... its so cracked now it wont stay in place! every few minutes I had to stop, and make sure my handlebar grip was nice and tight so the the throttle would stop sliding around! VERY annoying!
Thats about the only things I found........... For the most part, all seemed pretty good with it today.... Wanted to say thanks to all the people that help me diagnose the original issue too! Saved me who knows how much money by fixing it myself! Anyway... if anyone has any ideas what the above lil issues... lemme know! thanks!
09-28-2007, 06:34 PM #2
- Join Date
- Jul 2007
- near Toronto, Canada
Push and pull on the engine (engine off, and not hot), and be sure it stays put. It really shouldn't move much, and what movement there is, should only be from the rubber motor mounts flexing. If the motor is loose on the bedplate, or the mounts are not firmly attached to the hull, that is not good.
Did you use an alignment tool to be sure the motor and pump are perfectly lined up?
When you pull the pump to change the rubber bumper, look very carefully at the driveshaft splines. Look for ANY change from when you first installed that pump. Also review the splines in the coupler, and the impeller.
When the pump is back on, check how much fore to aft play there is in the driveshaft. A bit (not sure how much) is OK, a lot might mean the motor is out of position.
When you next have it on the water, you might try running with the seat off, so you can watch the engine as you accelerate. Might give you a better idea what is making the noise...
I am sure others will suggest more things to check.
09-28-2007, 06:55 PM #3
- Join Date
- Oct 2006
- Cleveland OH
2. Check for something "dropped" into the hull. Most stuff that falls into the engine compartment will work its way under the engine. Possibly the low vibration you hear. 3. Engine gets pretty hot pretty quick with no water circulating. I think the thermo opens at 120*, I'd remove it altogether personally. 4. Steering should follow the nozzle direction. Make sure the cable is tight under the hood and at the pump. Good job with the fix, and you did save a ton by doing it yourself.
09-28-2007, 07:07 PM #4
- Join Date
- Sep 2007
- In the woods
Check it again after you get your new bumper.Cane
09-28-2007, 09:12 PM #5
Polaris watercraft have an inherent vibration in the 2500-3500rpm range. If it seems to be happening around these rpms than it is perfectly normal.
For the thermostat, I would personally just remove it...the engine will run much cooler which is a lot better for it...it will stay plenty warm for what it needs.
09-28-2007, 09:32 PM #6
I checked the mounts when this whole noise started awhile back, but tomorrow im gonna check again, in a little more detail... they didnt seem to be loose at all, BUT that would explain it.... how common is that they come loose or break? The vibrating is DEFINATLEY coming from the engine area, you can hear it and see it when the seat is off. But its not major, just enough to not seem 100% right. With all that bouncing around on the waves and with all that weight, seems like it would be a common thing that the mounts could break or come loose. I did not use an alignment tool when installing the new pump... it all come together as one piece, just bolted it on and went. How does the alignment tool work and where could I find one? Whats the best way to test how much back and forth play is in the driveshaft? Through the bottom?
Yeah, last time when all this originally started I checked for things dropped in the engine compartment from the last owner.... I found 2 old rusted spark plugs, some random nuts, and a piece from a broken beer bottle! Must of used the comparment as a cooler, ha. Im not sure whats up with the steering at all. I loosened both nuts on the handlebar end, where it goes through the hull, squared up the nozzle and handlebars, and retightened the nuts. Out of the water, all looks good, but when you get going at full speed on the water, you have to keep a slight turn on the handlebar to go straight, VERY VERY annoying!
Thats sounds about the RPM range of the vibration... I noticed that idling in water it was around 1500 or so RPMS, and the vibration was most noticeable as soon as you hit the throttle and initially get on top of the water... As for the thermostat... I was going to originally take it out, then decided not to, now might do it again, ha. What COULD happen as the result of taking it out????
09-28-2007, 11:00 PM #7
- Join Date
- Jul 2007
- near Toronto, Canada
When you rock the motor around by hand, you should be able to feel if there is any play in the mounting, or just the rubber flexing slightly under pressure. It is also possible for a rubber mount to break, so watch for that too.
The alignment tool is basically a long, precision made rod, that ensures that the entire jet pump is in fact perfectly in line with the crankshaft axis of the motor. It is easy for the motor and the pump to not be properly lined up.
Beerdart sells and rents them, and possibly someone in you area has one you could make use of. Search for "alignment tool", there is info here on how it works, and how to use one.
If the pump and motor are not exactly in line with each other, excessive wear can occur in the drive shaft splines, and/or the jet pump impeller bearing, and it can also cause strange noises, since the drive line is under a stress that is not supposed to be there.
These motors do vibrate more at certain RPM, but you want to be check that there isn't something amplifying or reacting to that inherent engine vibration, and making things worse.
What do you mean by "you can definitely see it with the seat off..."
Not sure what to say about the steering bias, but really look over the nozzle assembly. Is there is something out of whack or bent back there?
09-29-2007, 02:08 PM #8
Just a note of interest...during the assembly process, Polaris did not use any type of alignment tool or alignment process for the drive shaft. They figured the shims needed on the motor mounts on the first couple of boats and then just did the same on all the rest. Which is a mazing to me since the SMC molds can very from the pump housing mounts to the engine mounts. I guess that's why they came up with the rubber bumpers, donut coupler and the oval splines on the drive shaft...more forgiving for non-proper alignment.
09-29-2007, 02:13 PM #9
going out right now to check every motor mount, and install the new rubber ends on the driveshaft... gonna check the splines real good too.... I pmed Beerdart about renting the alignment tool... As for my steering... i have no idea whats going on there..... Ill loosen the steering bolts again and redo it I guess.... ill post what I find! Thanks fellas...
09-29-2007, 05:58 PM #10
ok, just came in from replacing the rubber driveshaft bushings....... I was amazed at how the old one on the engine side had been worn down to basically nothing... the splines of the driveshaft were fine, and with the pump off, I took a good look at the wear ring of the new pump. After riding it hard for 4 hours yesterday, there was absolutely no rub whatsoever on it, so im guessing the alignment on the back end is perfect? As for the engine mounts, I checked everyone that I could see and get too, they were all as tight as they could be. I tried shaking the engine, I couldnt get the thing to budge one bit. Could the lack of the rubber bushing on the driveshaft side be enough to cause the minor vibration I felt yesterday? I dont see how, but then again, what do i know! As for the steering issue, Im guessing the steering cable thats in mine is not the original. Is the cable typical ran up underneath the engine? Oh yeah, the slight vibration that im seeing and feeling... ive got brand new spark plugs on, and they are probably gapped, ill check again, just to make sure. Any other engine timing possibilities or electrical issues that I should check out?
Last edited by Sabu1984; 09-29-2007 at 06:01 PM.
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