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Aq130c compression - Valves or Rings

P

pcmpete

Member
My AQ130c compression readings are as follows:

Dry Psi
125
150
150
140


Oil Psi

150
175
180
174

Is this a sign of bad valves or pistons rings (or both)

I do get some blow by and use about a quart of oil on a full day outing.

All help and advise welcome :confused:
 
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Thank you for the good advice, I will try the seafoam first, then the leak down. How much and for long will I get a smoke cloud from the seafoam. I live in a HOA area and neighbors can get a bit fussy. Or is it a good idea to use the seafoam at the lake?
 
kimcrwbr1 said:
All I can find is 12 degrees base timing and 27-29 DBTDC at 2000 rpm, WOT rpm 5100
Click to expand...

Ignition advance that is Full In @ 2k RPM does not sound correct.
You'd best check your OEM manual for this.
Your ignition TA (total advance) is more important than than your BASE advance, as long as BASE is within reason.
Any change to BASE will render an equal change to TA.

As for oiling cylinders to check cylinder pressure failure rings -vs- valves:
This being an inline vertical cylinder engine renders this an OK test in that the piston decks are horizontal, which eliminates oil pooling on an otherwise low side.... such as V engines.

Make sure that you add an equal amount of oil to each cylinder.
Reason; oil alone consumes volume, of which will intrinsically increase cylinder pressure.
IOW, an un-equal amount of oil can give us a "False Positive".


.
 
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RicardoMarine said:
Ignition advance that is Full In @ 2k RPM does not sound correct.
You'd best check your OEM manual for this.
Click to expand...

I can confirm that for the AQ130C, there are no other timing specs mentioned in the OEM (or Seloc) manual other than what kimcrwbr1 posted above.
 
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