Happy New Year everyone.
I have a few of questions about my 9.9 rebuild project.
First, I did a compression test on the engine. Initially, I sprayed fogging oil in the spark plug holes and ran the test. Came up with 120 on one cylinder, and 115 on the other. I then ran the engine for a few minutes. A day later I performed another compression test, this time without the fogging oil. The compression came up as 90 on one and 95 on the other.
First question: which set of readings is the correct one? Does fogging oil contribute to a higher compression reading?
The engine was used in the Chesapeake (brackish water) without a zinc anode on it. The previous owner flushed it after each use (he knew enough to do that), but the engine still has some corrosion issues. I was able to fire up the engine briefly and it stayed at temperature with good apparent water flow.
I removed the exhaust cover and dremelled out the thin layer of corrosion buildup that was in the water passages. It now looks pretty good. I'll do the same for the intake cover and the water jacket.
My second question is: should I remove the head to clean out any corrosion that's present in those water passages as well? Obvious concern here is stuck bolts (I've had a few, but managed to get most out).
Third question: if I remove the head, is there anything I can do to improve the compression on the engine (if necessary)?
And now a question that does not involve the powerhead. The tilt bolt assembly appears to be frozen. In its current state, the engine can be tilted, but only with a lot of torque. I'm afraid that I won't be able to tilt the engine once I get it on the boat, so I'm trying to loosed it up. I've been able to remove the tilt bolt nut (#0306319), exposing the tilt bolt spring, but it's still just as stiff. I assume the problem must be the conical washer on the other side of the bracket.
Fourth question: any suggestion on how to loosen the tilt bolt assembly?
As always, thanks for all the great advice from this forum. I've really enjoyed tearing this thing down. Hopefully I'll get it back together and working again. :happy:
Regards,
Jonathan
I have a few of questions about my 9.9 rebuild project.
First, I did a compression test on the engine. Initially, I sprayed fogging oil in the spark plug holes and ran the test. Came up with 120 on one cylinder, and 115 on the other. I then ran the engine for a few minutes. A day later I performed another compression test, this time without the fogging oil. The compression came up as 90 on one and 95 on the other.
First question: which set of readings is the correct one? Does fogging oil contribute to a higher compression reading?
The engine was used in the Chesapeake (brackish water) without a zinc anode on it. The previous owner flushed it after each use (he knew enough to do that), but the engine still has some corrosion issues. I was able to fire up the engine briefly and it stayed at temperature with good apparent water flow.
I removed the exhaust cover and dremelled out the thin layer of corrosion buildup that was in the water passages. It now looks pretty good. I'll do the same for the intake cover and the water jacket.
My second question is: should I remove the head to clean out any corrosion that's present in those water passages as well? Obvious concern here is stuck bolts (I've had a few, but managed to get most out).
Third question: if I remove the head, is there anything I can do to improve the compression on the engine (if necessary)?
And now a question that does not involve the powerhead. The tilt bolt assembly appears to be frozen. In its current state, the engine can be tilted, but only with a lot of torque. I'm afraid that I won't be able to tilt the engine once I get it on the boat, so I'm trying to loosed it up. I've been able to remove the tilt bolt nut (#0306319), exposing the tilt bolt spring, but it's still just as stiff. I assume the problem must be the conical washer on the other side of the bracket.
Fourth question: any suggestion on how to loosen the tilt bolt assembly?
As always, thanks for all the great advice from this forum. I've really enjoyed tearing this thing down. Hopefully I'll get it back together and working again. :happy:
Regards,
Jonathan
