New Engine after 18,000 miles

[sidthesloth]

My gauge has a flexible hose. It is hard to get at. I take off the seat and met-in box, then screw in the fitting by twisting the hose by reaching under the body plastic and guiding with my right hand. If you want to remove the engine shroud, you can without removing the exhaust but it takes a lot of twisting and is a big pain. How did you go about removing the side panel? I have only taken the whole lot off as one piece.

[rigpa]

After much weirdness with the parts dept at stadium yamaha, i finally have my rings, circlips, and head gasket.  My order came with a little black o-ring, but the parts guy doesn't seem to know where that goes.  Does anyone know if that fits in the groove on the head gasket? 

Also, I'm going to deglaze my cylinder bore with a scotchbrite pad.  Does it matter how i clean it in terms of going up and down or sideways with the pad?  I also read somewhere that you can use oven cleaner to deglaze.  Anyone think this is good/bad?  Thanks.

[sidthesloth]

No, nothing goes im the groove of the head gasket, that squashes flat when you torque down the head. For the bore, I would use a hone, mine was only $20. You will be on your way in no time. You dont need to remove the body but it does make it easier.

[Hoolander2]

Scotch Brite should be fine.  Move it mostly at an angle -- neither straight up and down nor sideways. Whatever deglazer solvent you use, be sure not to breath in a lot of it.  Have a fan blowing across your work area and have door or windows open.  Oven cleaner requires gloves usually. After deglazing, a thorough spraying with WD-40 to get the oven cleaner off and flush debris out of all ports.  Finally, wipe fresh motor oil or two stroke oil all over inside the bore. 

Maybe you'll find out where that o-ring goes when you take it apart. 

Did you get a new piston wrist pin?

[rigpa]

i got two new wrist pins.  anything special about installing these?

[rigpa]

i haven't yet done the compression test.  I will when i start to tear into the cylinder, well b4 actually.  I'm suspecting i have at least a poor, worn oil ring.  the scoot's been consuming oil and spitting it for a couple of years now.  plus once or twice the oil pump feed that goes into the carb came out and it stopped running/seized.  from what i've been reading 2 strokes get a lot of carbon build up.  i don't think the oil leaking helps.

one day last week, while going up my one very extended hill on my commute, let's say i'm wot for 10-15 seconds going very slowly due to whatever, poor compression, carbon blockage in the muffler, exhaust port, the scooter started to die, so i backed off the throttle and hit it again and she regained her slow but steady pace.  any ideas why this might have happened?

[thebatman]

well my scoot drinks the oil.. i get around 13-15 tanks of gas per bottle.... yeah, you may have carbon build up.. i recently discovered my nasty buildup.. seafoam does seem to have really helped this very quickly....you really need to test things......... the carb may need some cleaning......as i recently learned, check ALL the gaskets for leaks while at it.. ..

[wordslinger]

seafoam does seem to have really helped this very quickly

..it only gets better...

..keep using it..i have, and my a50s exhaust just keeps on opening up...

..i've had to up jet 3 times...

[Hoolander2]

Strange you should get 2 wrist pins.  Maybe one is a couple thousandths larger than the other just in case there is wear inside conn rod? You can try to test fit both through conn rod.     

Well, you just don't want to force the piston back and forth too much when removing/installing it.  Take out the circlips which hold in in place with needlenose pliars.  They'll deform easily so hope you got new ones with your parts.  If not, can bend em back into shape but better to have new ones. Once they're out, sometimes the wrist pin will just slide right out with a little pressure.  Sometimes have to bang on it.  If so, back up behind piston with rags or small pieces of wood.  Same for new one going in.  Oil it and it's races in piston and conn rod first. 

[Hoolander2]

Just a thought:  Check for inscribed writing/numbers on the ends of those wrist pins.  Maybe size info there? 

[sidthesloth]

Early zx had 10mm wrist pin and later had12mm pin. They may have given you one of each? But the pin would have to fit the piston.

[thebatman]

sid is right..the 01-02 models have a weaker 10mm ...the 03-04+ went to the stronger 12mm.

[sidthesloth]

Thanks batman, I wasnt sure of the year, I was thinking 04.

[rigpa]

that little white plastic thing underneath the gas tank is the fuel filter right?  how does one clean those?

[sidthesloth]

The inline filter is usually disposable. The screen in the tank is reusable, to get to this one you need to drain the fuel from the tank and remove the fuel cock. Be aware there is an o-ring in there too.