Xp 800 pistons stuck !

[Britrick]

Been trying to remove the pistons from this 96 XP800 , had plus gas in the barrels for a week then tried to move them but no luck , unbolted the barrels(jugs i believe you guys call them, lol, jugs here are womens .......) and managed to then gently tap down the mag piston and free the rings which were corroded to the barrel with the wooden butt of a mallet ,after about an inch of movement the piston became very reluctant to go any further but did eventually come out .Theres not really much visable damage on this piston apart from some light rubbing inline with the transfer port .The PTO piston however is refusing to budge at all !! i still keep putting plus gas in the barrel which dissapears after a few hours so it must be getting down past the piston rings which would mean the rings are no longer stuck to the walls but the piston just will not move!! again on this piston i can see no visable damage the top is in nice condition ,very clean , and the piston skirt that can be seen through the exhaust port is again like new !
So could the pistons of expanded for some reason and not shrunken back again ?
How do i get this last piston out? any ideas ,could i heat it ? but that would just expand it more surely ?
On the up side now the mag piston is off and the barrels are loose i can see the crank is not siezed and looks clean although may need a rebuild.
Alot of the water ways are clogged with a clear/white wax like substance ,but i dont know if they have gone like this over time whilst the engine has not run or if it was running like this and overheated , but then cant see any heat damage to the pistons.
My guess is that the bores have been honed ,can still see the cross hatching , and the pistons cleaned and put back in ,still has original pistons , then not long after this it has suffered a problem , or has been left and not winterized.
Any ideas apprieciated,
Thanks in advance
Richard.

 

[Dr Honda]

The reason they are stuck is because it sounds like the rings are rusted to the cyl walls. Don't use gas. Use ATF, or a real penetrating oil. (like PB blaster)

Since they are stuck... I'm going to say the crank is rotten too.

The reason for it is... the engine had water in it.

 

[Britrick]

Hi, yes on the mag piston the rings were rusted to the walls ,after a week of plus gas ,(penetrating oil ,best there is in UK) , i tapped the piston down but after an inch of movement it became very reluctant to move again as if it were to tight for the bore.
The PTO piston seems worse , i made a puller with a brake caliper piston compressor ,bolted it in to the head bolts and tried to wide down the piston and therefore pull the barrel upwards but again it was haveing none of it ,just bent the 3mm steel bar bolted across the bore!
yes i presumed the crank would want rebuilding but at least its not corroded and stuck solid like i feared!
Thanks.

 

[racerxxx]

You can't force it. Leave the jugs bolted down and get an impeller tool like I suggested in your other thread(I think?). You need to rock the engine back and forth and back and forth. I have un-seized V-8 engines that have sat untouched for 25+ years, and then got them running. The rings might seize to the walls, but what I have seen in vintage Ski-Doo snowmobiles is the aluminum piston oxidizes to the metal cylinder wall. But by rocking the crank left to right will allow a bit of oil in with each rock. You might also be surprised at what the crank looks like. I just brought back 2 old Ski-Doo's that have sat for 18 years and didn't run. The one needed a piston but the crank was mint, amazing that such a thin coat of oil on the bearings can keep them from rusting, now if there was water in the bottom end of your engine then that is a whole nother story. The other thing you might be facing is if there was moisture in the bottom end the bottoms of the cylinders could have rusted, again oil and the rocking action will SLOWLY get you past this. You can't rush it, the only way those jugs are coming off is up. Go get an impeller tool.

 

[Spimothy Leary]

You can't force it. Leave the jugs bolted down and get an impeller tool like I suggested in your other thread(I think?). You need to rock the engine back and forth and back and forth. I have un-seized V-8 engines that have sat untouched for 25+ years, and then got them running. The rings might seize to the walls, but what I have seen in vintage Ski-Doo snowmobiles is the aluminum piston oxidizes to the metal cylinder wall. But by rocking the crank left to right will allow a bit of oil in with each rock. You might also be surprised at what the crank looks like. I just brought back 2 old Ski-Doo's that have sat for 18 years and didn't run. The one needed a piston but the crank was mint, amazing that such a thin coat of oil on the bearings can keep them from rusting, now if there was water in the bottom end of your engine then that is a whole nother story. The other thing you might be facing is if there was moisture in the bottom end the bottoms of the cylinders could have rusted, again oil and the rocking action will SLOWLY get you past this. You can't rush it, the only way those jugs are coming off is up. Go get an impeller tool.

well this is a much more practical approach, i was going to suggest using a cutoff tool to cut off the rod, then take an impact hammer to the piston thru the jugs since I was assuming a fubar crank and a re-bore on the cyl's.

 

[Britrick]

You can't force it. Leave the jugs bolted down and get an impeller tool like I suggested in your other thread(I think?). You need to rock the engine back and forth and back and forth. I have un-seized V-8 engines that have sat untouched for 25+ years, and then got them running. The rings might seize to the walls, but what I have seen in vintage Ski-Doo snowmobiles is the aluminum piston oxidizes to the metal cylinder wall. But by rocking the crank left to right will allow a bit of oil in with each rock. You might also be surprised at what the crank looks like. I just brought back 2 old Ski-Doo's that have sat for 18 years and didn't run. The one needed a piston but the crank was mint, amazing that such a thin coat of oil on the bearings can keep them from rusting, now if there was water in the bottom end of your engine then that is a whole nother story. The other thing you might be facing is if there was moisture in the bottom end the bottoms of the cylinders could have rusted, again oil and the rocking action will SLOWLY get you past this. You can't rush it, the only way those jugs are coming off is up. Go get an impeller tool.

Hi Racerxxx,thanks ,yes this was my first plan of action but unfortunatly wasnt able to rock the crank , found an impeller tool here http://www.thejetworks.co.uk/shop/sea-doo-impeller-tool-p-211.html , so may have to order this and bolt the barrel back down and revert to this plan , not so easy to find this tool here in the UK ,ebay has dozens available in the USA but not here .Have you ever encountered one where the piston has expanded ? seems to be more to it than simply rusted the rings to the walls.
To look at the pistons appear fine and with a little cleaning would be able to use again likewise the bores look ok too which is why i cant see why the piston is putting up such a fight to move! Wish i could post pics ,must learn. Do you use oil on top off the piston or penetrating fluid? doesnt help that the piston is frozen part way down the exhaust port and fluid runs straight out there if not kept leaning over.
The crank looks in alot better condition than i feared but not sure if theres much play yet and it will have to come out anyway as lots of crud from the waterways has fallen into the crankcase , i reakon this thing hasnt run in years looking at all the stuff in the waterways ,dont know what it is!

 

[racerxxx]

Brit,

Here you go Seadoo impeller tool on Ebay in the UK You need the 18mm splines--choose the correct one from the drop down.

Yes, being stuck through the ports SUCKS. I'm not sure if your working on this on a bench or if it's still in the ski. If it's out of the ski you might have to get creative to hold it. Possibly use a long piece of wood and a lag bolt to go through the front mount hole then the same for the rear but cut wedges for the rear mounts but also use a long piece of wood. It's not going to be a fast process, and you'll probably use more than a can of penetrating oil. If you have it out look through the intake ports on the Rotary valve cover and look at the counter weights of the crank, if they look clean open the magneto/stator cover on the front. Pull the housing off and look at the bearings if they look clean I would proceed with caution as to not damage the crank, it MIGHT still be useable. If it looks like the bearings are rusty you might just have to use any means necessary to get this thing apart. Do not use the nut on the front of the crank to rotate the crank, you'll run the risk of stripping the threads.


See if you can locate this stuff Kroil penetrating oil or WD-40, or PB blaster. Just keep soaking it. It's not so much the piston expanding, but when the aluminum oxidizes that expands and will "rust" the cylinder. Think of it like a doorstop that looks like a wedge. The oil needs to get worked down around the cylinder and the piston. And yes, I have had a piston oxidize to a cylinder wall. I have spent the good part of a week trying to free a snowmobile engine before, just to tear it down. I just wouldn't beat on the crown(top) of the pistons, especially if you think you MIGHT want to re-use them. That will depend on what the rest of the bores look like, I'm gonna say you need new ones and probably a bore job. And then when you get it all free you'll need to put the head back on and put a rope in the cylinder to get the PTO off with your new puller.

http://www.ebay.co.uk/itm/Kroil-1-G...t=Motors_Automotive_Tools&hash=item41634bea72

If you want to post pics got to photobucket.com or any free picture hosting site and upload your pics. From there you can get the IMG links and put them in the body of your post. So your link when inserted into the post would look like this:

 

[Britrick]

Cheers racerxxx , spline tool ordered . It is on the bench now , it was still in the hull when I got the first barrel off but I figured it would be easier with a bit more space .can't get the carbs off at the moment as some butcher has rounded the hex heads ! But that's another story for another day. I shone a torch through the pto Venturi and it looks pretty good in there , the stator is off but it's very rusty in there , not sure about the bearing didn't realise it could be seen . It looks like yours did inside the front cover at the beginning of your rebuild thread . Just amazed at what a fight this piston is putting up , it would be understandable if it was brown and rusty in there or it had run lean and had a massive meltdown !

 

[racerxxx]

Yep, the inside of my 787 was nasty for sure. Be sure to check that front bearing, lets hope that MAG seal kept the junk out of it and your crank might still be useable. You can replace the outer bearings on your crank if they are bad-- as long as the center ones are good that is. Well, you never know what your going to find once you get that jug:thumbsup: off. So which one do you have off PTO of MAG Jug? and how does the crank look from the top down?

The stainless bolts going through the carbs get white and powdery inside the carbs and will lock up tighter than a frogs ass in a pond. You might need to carefully drill the heads off the screws. Start with one that will just fit inside where the allen wrench would go(6mm) and drill in. If you drill in about 4mm with the bit and stop then slowly work up in diameter to a 13mm drill bit you should be able to drill just the heads off the screws, then soak the heck out of the white powder and pull the carbs off the bolts. Just take your time!

I assume your "torch" is a flashlight and not a real torch

Gotta love the differences in terminology! The torches in the U.S. pack a bit more punch then in the U.K. :lols:

 

[Britrick]

Lol yeah that sort of torch may of caused a few more problems , and the only jugs at my place belong to the wife ........
It's the mag barrel that's off and yeah it looks nice and clean down there to be honest , I was worried it would brown solid rust ! Bit of side to side movement in the con rod But no play up and down on the big end bearing .
Yes I figured the carb bolts would have to be drilled , that White powder was all over the manifold bolts as well but they were 8mm so easier to remove but damn tight and tricky to get to , would be a real pig of a job to remove if I couldn't of rolled the engine onto it's side in the hull .

 

[Britrick]

Well got the impeller socket , popped the engine back in the hull and bolted it down , couldnt turn it with the socket and breaker bar so soaked it for a few more days with duck oil , and kept trying it back and forth ,then this morning success ! the piston moved 3/4 inch and will now go up and down about 3/4 inch so the rings are unstuck ,still wouldnt go further than that though which is what the first piston did ,got stuck the further it went down , however now its moving should be able to get it out soon .Problem now is ,tried to get a bit to clever and put more pressure on the bar and snapped the impellor tool clean in half sending me flying back into the wall ,lucky no body was watching lol.

 

[racerxxx]

You can't try to force it. Now that you have it moving you now have to rock it bit by bit time back and forth lathering the oil to get past the rough spot. Time and patience like I've been saying. You must have had an extension bar on the handle to snap the tool. Keep soaking it with oil and go back to it every day. Now find a socket that will fit snug on the broken tool and weld it on or contact the seller and tell them it snapped and see if you can get a new one. You can't rush it! You'll get it apart and spinning.

 

[Britrick]

You can't try to force it. Now that you have it moving you now have to rock it bit by bit time back and forth lathering the oil to get past the rough spot. Time and patience like I've been saying. You must have had an extension bar on the handle to snap the tool. Keep soaking it with oil and go back to it every day. Now find a socket that will fit snug on the broken tool and weld it on or contact the seller and tell them it snapped and see if you can get a new one. You can't rush it! You'll get it apart and spinning.

Yeah i know ,got a bit excited seeing it finally move and pushed it to far i guess.
Still i wouldnt expect a spline key that thick to snap ,must of been made in China.