Bad first ride, a few questions for the pros! See PICS

thats my plan, getting a puller today to get the flywheel/stator off and finish splitting the case, clean it out, yamabond it, reassemble with new crank seals, clean carbs again and check jetting, etc and then run a mile, check plugs, etc. until I think its running fine.
 
Also take a real good second look at your carb boots while your at it. Small cracks open up when vacum is applied, look them over good and try to flex the rubber when you're doing it.
 
gil7247 said:
Also take a real good second look at your carb boots while your at it. Small cracks open up when vacum is applied, look them over good and try to flex the rubber when you're doing it.

Thats where the starting fluid trick is a life saver. Any air leak will suck in the starting fluid and engine will rev up. You want to do this as soon as sled will idle, less time for stuff to get hot. the starting fluid will evaporate rather quickly and it dont hurt as a cleaner for the bottom of the bell pan. Pay attention to the boots from carb to box, reed cage boots and case-end seals.
 
biglsells said:
Here are two pics of the actual piston, first is intake side the second exhaust.
it just seems like the left side had no lube! Anyway let me know what you think so I can chase down the cause of this thing continually failing.

Thanks RX1, I thought I needed an actual gasket for the case..


that piston looks just like the one i pulled out of my wifes sled when the oil pump bolts backed out and the pump quit turning.is your oil pump/housing/waterpump/belt all ok?
 
The symptoms are consistent with a lack of oil. Were you running premix? Check the oil pump drive.
 
I was not running pre-mix, was assuming the oil pump was doing its job. The belt is fine, housing is fine, pump looks just fine. If the pump failed, wouldnt both pistons have melted down?
 
Usually when the oil pump fails it dumps too much oil in with the fuel. Make sure and premix the first tank full and also make sure the oil pump cable is adjusted properly. Marks must line up on pump at WOT.
 
I'll check the oil pump and the marks upon reassembly, thank you!

OK I split the case tonight, interesting what I found. No debris in the two crank areas where the rods are but on the PTO side there was a large chunk of hard molten plastic that came out with the seal. Also the seal looked a little rough, I'll attach pictures of all these things. ALSO - the far left bearing on the PTO side, I noticed after the burn up as I pulled it over it sounded "clicky", well that is the bearing that has the "dowel" like rollers in it, not balls, and it looks like it could have at least 4 or 5 more of them, should it be chock full of them or is it supposed to be missing a few? Anyway, here are pics of the case split open, pto seal, molten hard mass, let me know if this helps at all.

Lawrence
 

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yamabond is a form in place gasket (goop) that you can get for 8 bucks almost anywhere. i recently rebuilt a 99 SRX and used yamabond 5 per the manual. spread a thin layer on both halves of the crankcase before resealing. when you torque everything down you should see the material push out from between the case halves, meaning you've used enough. if yoyu dont see thuis you probably should seperate and give it another go
 
biglsells said:
I cleaned the carbs a month ago during the rebuild but since I have the motor out now I'll go ahead and take them apart and do it again. I do have a replacement seal for the PTO side, how do I get the old one out? I'll have to order one for the pull start side. Thanks for the reply stein700sx

I have a leftover pair of new crank seals from the 1996 Vmax 600 that I had. I am not sure if they are the same or not but you can have them if they are the same. I also live in Grand Rapids.
 
twyztid thanks a ton, when I redid the top end I ended up buying a full gasket kit so I've got the two crank seals, wishing I would have put them on then!
 
it looks like an oil issue i had a sx exciter that did the same thing oil pump was bad rebuilt complete with new oil pump put 22000 kilos on after problem solved.if its a lean condition usually its the exhaust side of the piston that scuffs.ive seen cold seizer look like that but i would suspect oil pump.
 
The pre-mix suggestion is that any time you have oiling system apart your going to end up with a bubble or two. By pre-mixing some fuel and having pump giving it more you end up with a too much oil rather than not enough. Did you pull motor first time around? If no than pre-mixing then wouldnt have mattered. Know that you have I would recomend some pre-mix.Dont think I would go a whole tank of pre-mix as you cant really tell whats going on with reading plugs and piston wash while double oiling so to speak.
 
I'm checking the oil pump tonight, I thought I would spin it with a drill, would this suffice? I'll also run double oil, a couple gallons anyway to see how it does the first time out.

Had to replace the PTO side bearing, it was junk, the metal brace that holds the rollers in place was non-existant and the small "dowel like" rollers were just flopping around in there, what a mess - got that bearing ordered today. The inner chase looks to be pressed on and appears to be in fine condition, does anyone know if this is a pressed on piece? Picking up yamabond and the bearing Thursday to begin the rebuld. New piston/rings/gaskets will be here Weds. I cleaned the crank and all the bearings on it with cleaner, should I lube them all up with 2-stroke oil before re-assembly? Also there are lots of little ports and holes on the case that seem dirty or almost plugged, gonna clean those up so its nice and new. I hope this thing runs.
 
ok cleaned the crases really well, cleaned the surfaces, got yamabond 4 to put them back together. Got the new PTO side bearing but when I was spinning all the other bearings I noticed something. There are two bearings on the pto side outter, the outter most one which I just replaced and then one right next to it. The 2nd bearing in (right next to the one I just replaced) makes some noise when spinning it and feels a little rougher than any of the other bearings, there is no play or give with it, just noise and feeling. Will this be ok or do I need to replace that bearing as well? That one looks like its press on, just like the inner race of the bearing I just replaced, am I correct and if so is this going to be expensive? I've almost spend as much as I could have spent on a complete replacement engine locally so not sure if I should move forward and finish fixing it or part it out and go get the other motor.
 
Did you lightly oil the bearings after cleaning? If you didn't even a new bearing would sound rough with NO oil in it.
 
no I have not oiled any of them yet, I'll oil them all with 2stroke oil before reassembly but being "dry" that bearing made noise where the others did not. It just feels like it took the brunt of the load since the outter most failed, just wonder if it is ok now that I have a nice new bearing on the outside. I am guessing this bearing will be another hundred bucks, then at least another hundred to have the old parts pulled from the crank and re pressed on. Buy a replacement motor?
 
600 engine

FYI, there's a 600 engine on GR Craigslist for $500 in Whitehall, and an SX600 partout on GR Craigslist as well. Not mine, just happened to see them listed.
 
OK - I love it when people follow up and "close out" a thread, not that I am closing this but I am posting what I believe will be helpful information for some. I finally got my sled all repaired and running nicely and there were several things causing this engine to continually blow. For one, I had a shot pto crank bearing which I think aided in wearing out the pto crank seal causing the pto piston to run lean. Fixed the bearing, new seals everywhere, etc.
After a few others said it looked like lack of oil I began to wonder about my oil pump so I took it off, hooked up my drill to it and held it at WOT and sure enough, pumped out oil nicely but when I put the pump back on and pulled it over, nothing came out. I also noticed that it went on rather easily, I figured the first time I had the flat shaft luckily lined up with the groove in the water pump shaft. As it turns out, my oil pump had not been spinning whatsoever, the tab shaft on the pump was worn down on both corners and was sitting, still, while the motor hummed away.

THANKS to a very generous person here on TY who sent me a pump for free, I have a fully functional machine again however I think I need to share pics as a lot of models used these pumps and I suspect they are prone to wearing down. I found several for sale on ebay and other internet parts houses with pictures and they were ALL WORN DOWN and useless.

The two pictures show the BAD PUMP with worn out corners, it will not spin and you will cook a motor. I actually bought a replacement pump from another user on these forums that was just like this, hope he will refund me wink wink. The GOOD PUMP has a nice full tab and you can actually see the wear markings a little bit where the shaft spins it.

Anyway, everyone on here has been extremely helpful and generous and I wanted to thank you all. Now, if we could just have a nice winter next year I can put more than 2.5 miles on this thing.
 

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