BS 350 pistons stuck?

[bsforever]

I hope someone that reads this post could possibly give some input for a 'stuck pistons' on the 350 BS. I pulled the heads off today, found there was no head gaskets  , but anyway, the cylinder walls look very good as far as i could see with no damage on them whatsoever (6,000 miles on the odometer)....so yes, i am a happy camper seeing that. However, since there isn't any appearance of any rust or damage that i could see of, why would the pistons not budge? Could there be another problem some where else within the engine that would make the appearance of having stuck pistons? I have had the bike in gear to rock it back and forth to hopefully see some movement with the pistons , but there is no movement. I just want to know if there is any input/answers to the problem i have with regards to another area within the engine itself , and if there would be, i would not want to further any more damage to the engine if there is something else other than 'stuck pistons'. I have been spraying PB Blaster in the cylinders daily since i got the bike (4-23-11), but something should have moved by now and hasn't.

[ztnoo]

Well, you say you have the heads off, but you don't mention having the barrels (cylinders) off or attempting to get the barrels off, so I'm wondering how you can make the evaluation the pistons aren't "stuck" in the bores below where you are viewing them?

You might want to review the "It be stuck....." thread:
http://bridgestonemotorcycleparts.com/index.php?topic=772.0

Just my worth....

[Toystoretom]

It wouldn't be a bad idea to drop the exhaust pipes and try and pull the cylinders up off of the pistons. If the cylinders do come off you are a lucky young man ....

Keep in mind that the crankshaft may be frozen and will not turn. This may fool you into thinking the pistons are seized in their bores when they are not. This is why you should try and pull the cylinders up off of the pistons.

Lets speculate that the cylinders DO come off, then how did the crank get locked up? A bearing may have rusted after sitting for so many years, or maybe there is some kind of mechanical damage that happened way back when, which may very well be the reason the bike was parked in the first place.

I'm afraid that you will probably have to tear this thing down and scope out the damage, something is wrong somewhere. If this is more than you want to do there are folks on the board that may be able to rebuild the motor for you (for a price, I'm sure) or you could just sell it to me  .

I suggest you look at the GTR shop manual posted on this website and it will give you an idea how the engine assembly was built and what it takes to tear one down. I would much rather have bad bearings in the crank than damaged cylinder bores. You can probably get all the bearings and seals that you need from Richard and have someone like Bill Bune enterprises rebuild the crank for you, a very do-able deal. Foo Bared cylinders are some bad mo jo, you won't find any NOS any time soon so if they are savable you would have to have them nikasil lined. Not impossible but not cheap either.

Keep us posted, we like to help. I'm worried about the no head gasket thing, maybe someone tried to free this engine up in the past and gave up and put it back together. Does the guy you got it from have any insight as to the condition of the bike or what happened to it? Any kind of clues or info may help...

[bsforever]

The previous owner of the bike died from a heart attack ( age 36) his widow put the bike on consignment auction, and i had won the bidding....... she did not say anything about what was wrong with it, i am sure she did not know, only thing she said to me was that her deceased husband was going to restore it....unfortunately he was not going to get to restore it. I did pay closer attention to what was going on with the engine after the previous reponse ztnoo had given, and although the cylinders looked to be good , closer inspection of the cylinders that were exposed above the piston let me know that something did happen , woke me up to the details of the lack of the headgaskets, left side of the engine was missing screws ( was only one ) to hold the cover over the carb on the engine.....well,i hate to say it, but have a scoured cylinder ( left one ), it was unnoticed at first , but it is definately damaged  I will not make assumptions in engine condition until i have the jugs off, could happen the right cylinder might be junk as well..... but will not assume anything until i will see the full inner bore of both of the cylinders. thank you for your input, i was looking if there would have been any other possible illusions that would look like stuck pistons. I will post my findings when i have the jugs pulled. Thanks ztnoo,& toystore .........very much appreciate the input

[bsforever]

Got it all freed up today and cylinders up from the pistons, will need to remove the engine to pull the jugs off all the way, but it is not stuck anymore. I did not incur any damage to the walls during the process of lifting the cylinders, but can see down the length of them and does look that there scratch on the left cylinder is just above the exhast port...the right one has a smaller amount portion of the chrome missing  on the rear side of the cylinder (towards the back but in the cylinder), but neither cylinder has damage the full stroke of the pistons. I would like to say also that this was not part of my doing , but who ever was last working on the bike messed up big..... when i did have the jugs up i could see the counter weights on the crank and i could not believe what i saw........one of the screws that holds the air cleaner was laying on the counter weight, when the piston came towards the bottom of the stroke, the counter weight was up (visual) well, that screw would not allow the piston to come to a complete down stroke and could not go any more downward!!! I suspect that whomever it was at that time did not know that a screw was dropped in there and could not kick the motor over and parked it, and as a result of the years of sitting accumulated the moisture and stuck the pistons where it sat. I am not at all familiar with how the engine would run with the cylinders in the condition they are in, but i know the 2 cycle engines are very sensitive when it comes to running decent....not sure what to do next. 

[reed]

bsforever
Maybe we can help,how about some pictures of your engine from the inside etc.
I do a lot this type of work  in fact i am rebuilding my crankshaft on my GTR.
Right now!
Thanks.
Reed.

[Toystoretom]

Steve Reed is da man 

If you just had scratches you might be OK, but I would worry about missing chrome or spots where the chrome had flaked off. I don't think the remaining chrome would last very long if you ran it, but you never know. I would look into having them re-lined.

But hey... you are making some progress. Once you know what you are up against and what you need the project becomes fun and kind of takes on a life of its own.

That's strange about the screw down on the crank. It would be cool to be able to go back in time and slap people 

[bsforever]

I will try to pull the engine out over this weekend. My digital cam is out, but i will see if i can get a relative that has a working cam to take some pics and i can post them. I was checking out some processes of the re-chroming, i am not sure what the story would be, but i ran across a web site that offers the Nikasil plating and also say something about sleeving cylinders in aluminum block small engines. Web link: http://www.kenoconnorracing.com/Cylinder%20plating%20VS%20Cylinder%20Sleeves.html  Yes, i would atleast like to have explained to them that screws and such do not belong loosely inside any engine. Thanks again for the motivation to get me going on the jugs Toystore.

[OldSwartout]

but i ran across a web site that offers the Nikasil plating and also say something about sleeving cylinders in aluminum block small engines. Web link: http://www.kenoconnorracing.com/Cylinder%20plating%20VS%20Cylinder%20Sleeves.html

One of the most-used services to refinish the chrome cylinders is Millenium Technologies  www.mt-llc.com . They can do chrome or Nikasil (personally, the Nikasil seems to be better). There are a few others, usually advertising in the back of Cycle magazines. It costs $175-$200 per cylinder.  Richard Clark still has pistons and rings. 

That price for sleeving is interesting as it seems to be cheaper than just a replate but with more machine work required. The advantage they talk about of being able to rebore for oversize doesn't hold true for the 350 as there are no oversize pistons available.  However, other than that, it sounds promising.  i wouldn't expect any BS to get enough miles these days to ever require a rebore.