New problem! BIG Problem

[John Sharp]

I was ridin my sl780 when all the sudden it just died. I tried to start it back and it just clanked, like when the battery was dead, except I have a full charge on the battery.

I took the seat off and there was black oily stuff around #3 and the spark plug was loose, and the insulator in around the electrode was broke.

I fear that the push rod may have broke and allowed the piston to smack the spark plug. Is there anything else I can do to ekiminate say a bad crank before I try to tear into it? Oh and the spark plug was black with a little ashiness on it.





[ May 17, 2002, 08:47 AM: Message edited by: Bryan Glynn ]

[Bryan Glynn]

More likely, you had some detonation and part of the piston/rings broke the spark plug. Pop the head and take a look.

[John Sharp]

Okay I took the head off and there is definitely some debris in there. I guess it is the ring. I dont guess I can get away with replacing the piston and rings w/o removing the crank can I.

The cylinder walls are perfect, but you can see the damge to the piston edges and the head.

I have pics at webshots.com...my name is SharpTJ or I can email them to you if you like. I just dont have anywhere to host them.

[Bryan Glynn]

email them to me and I'll post them in your thread.

[John Sharp]

You got mail!! Thanks

John

[Bryan Glynn]

OK I got them - and it looks like detonation and parts of the piston/ring bouncing around - I'll post them inthe morning - my ftp session is taken up right now with the PWCtv episodes going up...you need at least a top-end job.

[John Sharp]

Great :( what all does top end job entail. What all should I replace, and what are the chances of something having gotten in the crank area? Thanks for your help.

[Bryan Glynn]

A top-end job is pistons, rings, and at least honing the cylinders. Your cylinders do look good, so most likely you can get away with just honing the one, and installing a new piston, of the same size. You probably won't need to go up a size, in which case you would want to do all three cylinders.

The chances are that that debris was contained to the top end and all went out the exhaust port - it's not severe enough to have likely contaminated the bottom end, but certainly inspect the crank while you have it disassembled doing the top-end.

[Joe St. Louis]

I hate to put a damper on your top end rebuild planes but it really looks like a piece of bearing cage on top of the piston, meaning one of the crank bearings came apart. Even if it is a broken ring only, you should disassemble the bottom end and at least clean the crank. I have never seen an engine have metal pieces bouncing around inside it and some pieces not find there way to the crankshaft. :D [img]/graemlins/winkanim.gif[/img] [img]graemlins/cwm3.gif[/img]

[Rider X]

I agree with Joe. Actually you had a lower rod bearing come apart. You will find when you pull the cylinder the lower bearing on the rod will have messed up the spacer washer on both sides of the piston rod. Very easy to see. Once you pull off the cylinder turn and see if the rod turns freely, my guess you will have lots of play or no movement at all. And the two bearings at least the two bearings closes to that crank journal will have to be replaced. have your crank rebuild with new rod. Those rust out pretty easy and do come apart often.
Sorry about that.

[John Sharp]

Thanks for your all help. I will probably dive into it Monday since school had finished. I guess I had better plan on a complete engine rebuild? I have heard about SBT engines, and have read some on the site but havent found prices or anything.

If I was to just do an OEM rebuild, where is the best place to get parts, cause the Polaris dealer here wouldnt know a piston from a battery.

If I do do this myself, you all will be hearing from me ALOT. So please bear with me and all my stupid questions.

John

[John Sharp]

Weel problem solved. I started looking more closely and there is a huge hole in the port side of the block!! So I am parting her out in hopes of gethering enough money to buy another. Thanks for your all's help. If you need any parts just holler. How much can I hope to make back from parts.