99 sx 600 randomly died and engine locked up

YZViper366

YZViper366

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Joined
Jun 23, 2011
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349
Age
33
Location
Bismarck, ND
My girlfriend had been riding her sled for probably 3 to 4 hours and when climbing a hill her sled just died. I go down to start it and the engine is locked up. I went and spun the clutch by hand and then pulled it over and it started. So i rode it a few hundred yards and the same thing happened? Any ideas what could be up? I have been told crank bearings?

Also the coolant was cold as were the heat exchanger's? Is there a overheat shut off on these sleds?

Let me know what u think.
 
if it locked up, then released and locked up again my first guess would be a rod bearing let go and the chunks are getting wedged between the case and crank. if this is what it is then you probably also have a crack in the bottom of the case now that will need to be welded or replaced. It could also have locked up from heat in the engine, everything expanding beyond the point of clearance. If your coolant is cold its obviously not circulating at all.
 
I dont believe theres an overheat shut off, Im assuming the coolant or oil light never came on? Or was flashing? Sounds like it was starved of oil or the oil pump quit, but if your coolers were cold it could also be your water pump.

The coolers under the running boards should be warm after about 5-10min of running depending on outside temp, I usually check mine before I leave the house, if they dont get warm I dont leave.

Is there play on the primary? (can you pull it in and out to see if there is play in the crank?) I know the cranks on the triples had a tendency to twist throwing the timing off, did it feel down on power before it died?
 
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My girlfreinds SxR 700 did the exact same thing. Center cylinder wasnt getting very much fuel. As cylinder heated up it would seize. Cool down grab clutch and free engine fired back up and seized again. Jug and psiton, gasket set and some yamabond and 800 miles later still running like a champ.
 
So what do you guys suggest i do? Is there any way to diagnose those without tearing the whole engine apart? If i could do this with just taking the jugs off ill be pretty happy. I have never have torn to deep into the engine before so im not to comfortable with it bit im sure ill be fine. Just hope its simple but i don't think i will b that lucky
 
Pulling plugs and the ehxaust manifold/pipe off is a good place to start. With any luck you shouldnt see any shiney peices floating around in them. With manifold off you should be able to get a ppek at the front of the pistons as well. Unfortunateley I would recomend pulling the motor. Any foreign material down in cases is BAD for longevity of crank/rods.
 
if its not moving coolant, first i would remove the waterpump cover and see if the impeller is still attached firmly to the shaft, they can sometimes eat up the splines if it comes loose.

if thats good, your not going to like what i tell you to check next..............


and thats the brass gear on the crank is likely junk, that involves taking the crank all apart and replacing it, or just get another good used crank. i have run into this before on the redhead triples a few times.
 
Got the engine apart and both center and mag side cylinders anf pistons are shot. Also found the cause some how the oil cable came undone from the throttle so the engine was not getting any oil. Bummer
 
YZViper366 said:
Got the engine apart and both center and mag side cylinders anf pistons are shot. Also found the cause some how the oil cable came undone from the throttle so the engine was not getting any oil. Bummer
Click to expand...

If those cylinders werent getting oil then neither was most of the rest of the engine. Hows the crank look? When the center cylinder burnt down on the GFs SxR 700 I had checked aound and had found several complete running red heads for not much more than it would cost to have crank rebuilt. Got lucky and crank was ok. Is she ready for a 700?
 
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The crank doesnt look to bad i think that i am going to run it there isnt a lot of wobble in the rod and it feels like it is turning nicely.

And to be honest i think she is due for an updated sled. I hate to say it but we want to do more mountain riding so we are looking at a 2011 rmk. I would rather her have a yamaha but everthing is to eavy for her or it doesnt hanfle or its to expensive to make handle well.
 
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