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Sick Little Scoot -> Update(No Compression)

Posted: Sun Sep 18, 2005 12:58 pm
by twsnagel
Thanks, everyone, for your continuing advice.

I opened the LHS, removed the starter bendix. Cranked the engine, no dice. I'm getting a spark, the carb is getting gas.

I bought a compression meter, there is NO compression. The meter starts at 50psi and there is no movement on the needle.

I pulled the cylinder head, the head gasket looked good so I knew the problem was deeper. I pulled the cylinder, and the cylinder gasket was in poor shape, but even worse, the top piston ring was completely destroyed.

The cylinder, the piston, and the head look in good condition.

There are no honda dealers open today, so I have to wait until tomorrow to order new gaskets and rings.

Do you folks think this will solve the compression problem, or is it a lost cause?

Thanks, folks.

Tyler

Posted: Sun Sep 18, 2005 1:12 pm
by vette76
should fix it. just make sure the cylinder wall/piston is in good shape. i recommend honing but its not always nessisary.

Posted: Sun Sep 18, 2005 1:31 pm
by Justinsane
well you might as well bore it out now that your gonna be cleanin in up.. :twisted:

Posted: Sun Sep 18, 2005 2:03 pm
by zoom
i heard boring a spree out does nothing is this true and if it is why?

Posted: Sun Sep 18, 2005 7:16 pm
by vette76
they only go 50 over. this is not much to make a difference. i have 50 over in my spree rite now. maybe if it was ported???

Posted: Sun Sep 18, 2005 8:44 pm
by noiseguy
If the cylinder is scored, you'll need a bore, if not just hone. If you don't know what you're looking for, take the jug to the dealer's shop for inspection. A $10 brake hone and some engine oil do a good job honing these.

With a hone job, you just need new rings. Otherwise, you'll need a new piston, circlips. etc as well as a bore job.

Posted: Sun Sep 18, 2005 9:07 pm
by burnt_toast
if the ring is destroyed, it most likely scortched the cylinder walls in the process of breaking. This is what happened when I went down a hill onetime and later had to replace piston and cylinder.

Just feel the cylinder w/ ur finger and see if its smooth all around, if the scratches are too deep, boring might not even work. Thats whathappened in my case, and I needed a diff. cylinder.

Posted: Sun Sep 18, 2005 10:50 pm
by twsnagel
OK, I'm still pretty new to engine work... What is honing, how do you do it?

Also, which direction is the main pulley supposed to turn when you are looking at it sitting next to the scoot, looking straight at it?

Posted: Sun Sep 18, 2005 11:05 pm
by vette76
the pulley turns the same direction as the rear tire. honing is somthing you do to take all the tiny imperfections out off a cylinder to make it super smooth. it is a special tool they sell for brake calipers that goes on a drill. if you have no knolage of doing this i would recommend you have it professionally done. its not that expensive.

Posted: Mon Sep 19, 2005 9:59 am
by noiseguy
vette76 wrote:the pulley turns the same direction as the rear tire. honing is somthing you do to take all the tiny imperfections out off a cylinder to make it super smooth. it is a special tool they sell for brake calipers that goes on a drill. if you have no knolage of doing this i would recommend you have it professionally done. its not that expensive.
The engine turns CW looking at the driven face, and turns the opposite direction of the wheel. Which, interestingly, is the opposite way the Aero 50 turns. 2 vs. 3 gears in the rear diff.

Posted: Mon Sep 19, 2005 10:28 am
by twsnagel
So which way does it turn? I see two different answers! I need to know because I'm starting it with a drill!

Posted: Mon Sep 19, 2005 3:22 pm
by vette76
whoops. sorry i was thinking of my dio engine. my bad.