2003 RX1 -Compression Test or Leakage test???

[tanglefoots]

Anybody know the what the differents is between a compression test and a leakage test on a RX1 2003?

 

[Buckeye]

A leak down test is a more accurate measure of the ability of the rings to hold a pressure seal. Poor sealing rings can still make pressure. With the leak down, you pressurize the cylinder and check the ability to hold the pressure with a gauge. The compression tests the ability of the cylinder to pump up the pressure.

Imagine a tire with a slow leak. You can pump it up to full but it will not hold pressure and go flat. The same is true with poor rings. A leak down test will reveal this.

 

[tanglefoots]

results of compression and leak down test on 2003 RX!

2003 RX1 mileage is 8000 miles or 12000 kms (My opion RED is FAST FASTER)

Compression Test done results
#1 cylinder 117
#2 cylinder 115
#3 cylinder 112
#4 cylinder 110

when a Wet test was done all cylinder went to 250

Yamaha say in service manual that 179 is poor 209 is normal and 225 is good.

Yamaha requested a leak down test the results were
# 1, 2 , 3, at 8%
# 4 at 38%


Know why the differents in results of test compression or leak down???

 

[Buckeye]

Something is wrong with those compression readings. The cylinders must have been very dry. As for the leak down, the #4 is in trouble. I have heard of others having cylinders out of round, probably from overheatingor detonation.
Were you using alot of oil?

 

[tanglefoots]

Did Cold compression test, warm up to temp to do the test results the same.
Did another test cold same results.
Only burning about 2 lts per 4000 miles.

no power, only will rev a 9000, after shift goes to 8000 rpms

 

[1xr]

I have found thay not all compression gauges read the same. Try another gauge or try your gauge on another rx1. It deos'nt sound right low compression and very little oil comsumption.

 

[tanglefoots]

did a compresion test on my 2004 rx 1 and it was 225 lbs all across we did a compresion test on a 2003 rx 1 with 4000 miles on it and it was 220 all across so we did a leak down test on it and it was between 8 to 12%between the 4 cyl this 2003 is supose to take a litter of oil per 100 miles that wy it was in the shop

 

[looking4speed]

When the compression test is done you need the throttle wide open.Do the vacuum slides need to be held open when the test is run?

 

[Birdman]

Wont a leaking valve have the same effect during a leakdown test as a leaking piston ring ?

 

[Mikey]

When doing the leak down test you have to listen with a stethascope to hear where the air is leaking from when you pressurise the cylinders then you will know where the problem is. It will either leak into the carbs or exaust then its a valve but if it leaks into the crankcase breather then its the rings,or you could have a possible head gasket leak if the air comes up in bubbles in the coolant. Basicly you are pressure testing your engine for leaks when you perform this test the hard part is finding where the air is leaking from.

 

[Sled Dog]

When doing the leak down test you have to listen with a stethascope to hear where the air is leaking from when you pressurise the cylinders then you will know where the problem is. It will either leak into the carbs or exaust then its a valve but if it leaks into the crankcase breather then its the rings,or you could have a possible head gasket leak if the air comes up in bubbles in the coolant. Basicly you are pressure testing your engine for leaks when you perform this test the hard part is finding where the air is leaking from.

Well said Mikey!