1988 SB50 sputters high speed

[smanke]

I did the compression test with WOT and 75psi was what I got. So that is bad news for me. I will be tearing it down this morning. I will post what I find. Where is the best place to get parts?

[smanke]

So I took off the cylinder head. The cylinder head is not warped. I can see into the cylinder and it's scored along the exhaust side of the wall. It's not too bad and should just need to be slightly honed. I didn't have enough time to get the cylinder broken loose and removed. I am assuming I will need to get new piston rings. As well I will need new base and head gasket. Is this sounding like the right path?

[Bear45-70]

So I took off the cylinder head. The cylinder head is not warped. I can see into the cylinder and it's scored along the exhaust side of the wall. It's not too bad and should just need to be slightly honed. I didn't have enough time to get the cylinder broken loose and removed. I am assuming I will need to get new piston rings. As well I will need new base and head gasket. Is this sounding like the right path?

If you can catch your fingernail in any of the score marks, honing will not work. You will have to bore the jug. You are also gonna need rings minimum and depending on what the piston looks like will determine whether you need a piston, if you don't have to bore it that is. If you have to bore it, you are better off getting a BBK.

[smanke]

Once I get the cylinder off I will determine what I will do next. If I decide to get a BBK where should I get one? Where can I get parts if I just need gaskets and piston rings?

[noiseguy]

He could also try to run down a servicable, used piston / jug somewhere from a reputable seller. Not the easiest thing though. As Bear says, even with a $30 aftermarket piston/rings (if you can find it) you'll be another $40 for bore job (unless you have the tools); you quickly get to the point of just starting with a bore kit.

Take a picture of the inside of your bore and we'll pontificate more

[smanke]

I am on a trip right now. I won't be home to take a pic til Thursday. I hope I can just get by with honing,new gaskets and piston rings. So what would be a good BBK for my scooter if I decide to get one? What else would I need to change if I do it? Thank you for the help!

[smanke]

So I got the cylinder off today. I checked to see if it's warped and it's not. I took a few pics of the bore. It's slightly scored on the exhaust port side as you will see in the pic. The piston rings weren't stuck to the piston. So where do you think I should go from here? I think a light hone, new piston rings and new gaskets would suffice. Or should I just get a BBK?
Here are the links for the bore pics.
http://i1000.photobucket.com/albums/af1 ... photo1.jpg
http://i1000.photobucket.com/albums/af1 ... /photo.jpg

[smanke]

So scooter gods what do you think I should do?

[Bear45-70]

Unless you can catch your finger nail in those scratches in the cylinder wall, all you need to do is hone the cylinder. The same applies to the piston, if you can't catch your finger nail in the scratches, the piston is OK. If you hone the cylinder you have to get new rings.

[smanke]

Well the scores in the cylinder do catch my fingernail. So the best thing to do is get a BBK then right? So where can I get one for a reasonable price? What choices do I have to choose from?

[Bear45-70]

Well the scores in the cylinder do catch my fingernail. So the best thing to do is get a BBK then right? So where can I get one for a reasonable price? What choices do I have to choose from?

The SB50 uses the same piston as the Spree, so if you want to go with just the oversized 44 mm piston and bore you cylinder, I think Taz sells them or the BBK which he also sells. Contact him via PM here on the forum. tazland001

[smanke]

I sent a message to tazland. Is there anywhere else I can get a BBK? Where can I get parts if I just decide to bore it? I'm going to need at least new gaskets, piston rings and piston.

[Bear45-70]

I sent a message to tazland. Is there anywhere else I can get a BBK? Where can I get parts if I just decide to bore it? I'm going to need at least new gaskets, piston rings and piston.

Not for a Spree or the SB50. Taz is the only game in town or the country, * maybe the world. He is a good guy and will take care of you.

[smanke]

I saw there is a 48mm BBK on ebay in Nevada. Is this from the same guy?

[Bear45-70]

I saw there is a 48mm BBK on ebay in Nevada. Is this from the same guy?

That's the guy, chopchop*123 is tazland001 here on the forum but he will give you a better price than on flea-bay by contacting him thru the forum here. He also has a 44 mm BBK that works better with the stock carb and exhaust. The 48 mm BBK need a better intake and exhaust system to get the most out of it. When Taz comes out with the intake, carb and exhaust then the 48 mm will be the way to go. The proceeding is of course is my opinion.