Compression

[ED.D]

Hello to all, 1st time post, so I will run through a little background and introduce myself. I am running an A4 in a 1977 Tartan 34. I bought the boat in 2001 and with the help of the Moyer manual I have learned the necessary maintenance and adjustments to keep it running. The engine has been dependable, and over the years I have added electronic ignition, fresh water cooling and a 80 amp alternator. While I have owned the boat (I believe I am the forth owner) the engine has never been run hard or for long periods with well under 50 hours per season and an occasional eight hour day. it burns a little oil, only noticeable from the occasional light blue/gray smoke exiting the exhaust, this is not always noticeable. I am hoping to take the boat south from Rhode Island next fall and I am in the process of deciding what to do this winter. Already on my list is a carburetor and fuel pump rebuild. Please take a look at the compression numbers below, any comments would be appreciated.

Wet was a tablespoon± of 10-40 oil.

Dry psi #1) 102 # 2) 92 #3) 95 #4) 101 - These are the average of 3 readings
Wet #1) 125 #2) 120 #3) 120 #4) 121

I also checked the compressions warm bringing the engine up to 180°
#1) 102 #2) 93 #3) 94 #4) 112

The reading on cylinder #4 is a mystery to me and I have not had time to return to the boat and clarify it.
Thanks for any input you may have Ed

[Nahart]

I wish I had those numbers...I'm doing a valve job as we speak.

[Dave Neptune]

Those numbers do look high however I would suspect the gage. They're all within ten pounds so all is OK.

RE the smoke and oil consumption try backing the timing off a couple of degrees and do check the C-advance for sticking while at it.

Dave Neptune

[joe_db]

Looks good to me

[sastanley]

I agree with Dave..a little high, but what is most important is they are all close!!

The C-advance is the weights in the distributor, under the plate. Make sure those operate freely. A timing light would help a lot to check this and to make sure you have the idle speed timing set correctly. We have other recent threads running to discuss this too. Does the T-34 have the engine up in the middle of the boat like the T-30? Some of us with poor access to the flywheel have found a great way to check timing (we think very precisely) with the accessory drive pulley. I am sorry I can't remember where the T-34 engine is located.

[ED.D]

Thanks to those who have taken the time to post so far. Yes the engine on the T34 sits in the middle of the floor providing better then normal access and the enclosure makes a good seat once the engine has cooled. I did see the posts about using the accessory drive for timing and it seems like it would be more accurate than the fat pin on the front of the flywheel.