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View Full Version : What compression shoud i get from a aq130



tonyr5500
08-31-2009, 09:29 AM
"hi again guys, did a compression test today and all 4 are reading the same at 75 psi 4.5bar is this the right reading for the aq130 or should it be higher? does any one know or where would i find out?

many thanks tony"

barryf
08-31-2009, 09:51 AM
"Tony, that compression is too low. Try pouring a table spoon of oil in the spark plug hole and doing the compression test again. Since all cylinders are low, it sounds like your timing belt has jumped a tooth or you are leaking past the rings. The wet test will help identify which. Does the engine run?"

olddawg
08-31-2009, 10:18 AM
"I don't have my book in front of me right now, but I believe that the 130 should be in the 140 to 160 range."

joe_merchant
08-31-2009, 11:03 AM
"Obviously, the manual is the best source of information. You really should have one if you're going to do any work on the engine.
Here are the compression numbers for the different versions:
AQ130A - 170-200
AQ130B - 145-170
AQ130C&D - 170-200

Your motor sounds like it's getting pretty tired. There is no timing belt on those. Some tips for getting accurate readings:
Throttle full open and all plugs out.
Battery fully charged so you get maximum cranking speed."

tonyr5500
08-31-2009, 11:28 AM
"hi guys thanks for your input, the engine runs a ok but can only get her up to 3000rpm was'nt sure if this is the prop being to big or its the engine i did see abit of oil that had looked like it had come out of the oil filler cap would this have sumthing to do with it? but there is a bit to much oil inher so was'nt sure if that would be why there is oil coming out of the filler cap?

"Some tips for getting accurate readings:
Throttle full open and all plugs out"
do you mean with the engine running or not?

thanks again tony"

joe_merchant
08-31-2009, 11:45 AM
"I was referring to the compression test so if the spark plugs are all out then it might have problems running!

It's really hard to tell why you're only getting 3000 rpm. It could be a combination of many things. A full tuneup is a start but realistically, with compression numbers that low and blowby from the valves and seals, you might want to take it easy on the motor so it doesn't come apart on you. It really sounds like some major work is in order. Just be careful how much money you spend. Rebuilding an old engine can put you upside down on the boats value really quick."

tonyr5500
08-31-2009, 12:03 PM
""I was referring to the compression test so if the spark plugs are all out then it might have problems running"
sorry abit of a silly thing to ask after rereading what you said,
thanks for the info joe will have along hard think about what iam going to do, have already spent alot of money on a new leg,alternator,batterys, ect ect the list goes on but as with any boat there is always things to be done,
thanks again tony."

joe_merchant
09-01-2009, 12:13 PM
"There are still some things to check to see if you can get the motor up to full rpm. With the tuneup, you should also verify that the distributor is advancing as rpm increases. The carb and the fuel delivery system is another area that you need to check.

If it turns out that the engine needs major work, most parts are still available for a rebuild. You've also got the option of switching to a newer overhead cam engine. From what I understand, the only major change is the exhaust pipe."