|
|
Post by riderboy on Aug 5, 2012 19:25:08 GMT -5
Hi guys there a scooter I want to buy. I know I will be needing to do stuff. Guy want 550. And they just got tags paid which is 90 bucks. Hes selling for 550. I went to his house and did a compression test. I'm not sure if it's my guage or really his piston and rings are worn out including cylinder. But didn't tight up the adapter to the plug hole to tight so maybe it's leaking? I'm affraid to strip it. Anyways. Here a pic and engine number.   |
|
|
|
Post by OverReved on Aug 5, 2012 19:47:30 GMT -5
I always do a compression test with a small squirt of oil in the cylinder and the engine at WOT while cranking.
Any other way seems like a cheat to me.
If you do it like I do and still get same results that cylinder is looking weak and you may want to consider replacing the hole and the piston-rings.
|
|
|
|
Post by kixome on Aug 5, 2012 20:21:24 GMT -5
Just had a guy last night on here testing everything and changing everything on his motor just to find out he kept reading 50psi because his guage was bad.
|
|
|
|
Post by kixome on Aug 5, 2012 20:21:51 GMT -5
iF guage is good then you might want to consider not buying it.
|
|
|
|
Post by riderboy on Aug 5, 2012 22:24:47 GMT -5
|
|
|
|
Post by riderboy on Aug 6, 2012 0:17:32 GMT -5
iF guage is good then you might want to consider not buying it. I know could have string attach. |
|
|
|
Post by gatekeeper on Aug 6, 2012 4:21:02 GMT -5
Screw the adapter in nice and snug, just like you would a spark plug. Hold the throttle at wide open while cranking the starter. Continue cranking until the gauge needle stops climbing on the dial. If the reading is still low, THEN put a little oil in the plug hole, re-install the adapter and retest. If the reading goes up by much then that indicates bad rings.
The scooter sounds like it starts easy and runs decently based on the video. That would indicate compression higher than 90psi but it is no guarantee.
|
|
|
|
Post by riderboy on Aug 6, 2012 6:10:14 GMT -5
Screw the adapter in nice and snug, just like you would a spark plug. Hold the throttle at wide open while cranking the starter. Continue cranking until the gauge needle stops climbing on the dial. If the reading is still low, THEN put a little oil in the plug hole, re-install the adapter and retest. If the reading goes up by much then that indicates bad rings. The scooter sounds like it starts easy and runs decently based on the video. That would indicate compression higher than 90psi but it is no guarantee. Oh crap forgot to tell the guy to hold full throttle. Would that be the cause? |
|
|
|
Post by gatekeeper on Aug 6, 2012 6:40:19 GMT -5
Yes, you need to hold WOT to help fill the cylinder fully with air. Not doing so will result in lower readings.
|
|
|
|
Post by riderboy on Aug 6, 2012 13:50:51 GMT -5
Yes, you need to hold WOT to help fill the cylinder fully with air. Not doing so will result in lower readings. Thank you. Darn he get out afternoon and I go into work afternoon. |
|
