Found a Top Gun on a tropical island!
#121
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From: Malaysia

#123
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From: Malaysia
Engine assembly is almost completed, pre-oiling with a drill showed a nice oil pressure, so I tried to turn over the engine with the starter. Went all well until I discovered that cylinder #1 has zero compression, all others are fine. Well, didnīt try with a tester, just with a finger but it is obvious that one cylinder has a problem.
Valves seem to open and close the whole way, but I donīt really know how to measure it. Took off the oil pan, all nice and clean, no debris or metal flake. Couldnīt see anything wrong at the cylinder walls or the piston from below.
Any suggestions what I can do before taking the cylinder head off?
Before I noticed that I had an issue I made a short video. Itīs not really focussed on the first cylinder, but something can be seen.
Valves seem to open and close the whole way, but I donīt really know how to measure it. Took off the oil pan, all nice and clean, no debris or metal flake. Couldnīt see anything wrong at the cylinder walls or the piston from below.
Any suggestions what I can do before taking the cylinder head off?
Before I noticed that I had an issue I made a short video. Itīs not really focussed on the first cylinder, but something can be seen.
#124
Engine assembly is almost completed, pre-oiling with a drill showed a nice oil pressure, so I tried to turn over the engine with the starter. Went all well until I discovered that cylinder #1 has zero compression, all others are fine. Well, didnīt try with a tester, just with a finger but it is obvious that one cylinder has a problem.
Valves seem to open and close the whole way, but I donīt really know how to measure it. Took off the oil pan, all nice and clean, no debris or metal flake. Couldnīt see anything wrong at the cylinder walls or the piston from below.
Any suggestions what I can do before taking the cylinder head off?
Before I noticed that I had an issue I made a short video. Itīs not really focussed on the first cylinder, but something can be seen.
https://youtu.be/eZuQHT9hiLc
Valves seem to open and close the whole way, but I donīt really know how to measure it. Took off the oil pan, all nice and clean, no debris or metal flake. Couldnīt see anything wrong at the cylinder walls or the piston from below.
Any suggestions what I can do before taking the cylinder head off?
Before I noticed that I had an issue I made a short video. Itīs not really focussed on the first cylinder, but something can be seen.
https://youtu.be/eZuQHT9hiLc
#125
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From: Malaysia
I guess I know why you are asking, if the valves are not completely closed it could explain the compression loss. In fact, there is no lash at all especially on the exhaust side.
Frankly, I never fully understood how hydraulic lifters work, how they manage to adjust the lash autmatically.
I set the valves to zero lash with the pushrod turning method, but I canīt say for sure if the lifters were filled with oil or not. Now they should be as after pre-oiling oil has traveled up all the way into the rockers.
Shall I just loosen a little until I have some lash? I was concerned that without access to the pushrods I canīt fully control it.
Frankly, I never fully understood how hydraulic lifters work, how they manage to adjust the lash autmatically.
I set the valves to zero lash with the pushrod turning method, but I canīt say for sure if the lifters were filled with oil or not. Now they should be as after pre-oiling oil has traveled up all the way into the rockers.
Shall I just loosen a little until I have some lash? I was concerned that without access to the pushrods I canīt fully control it.
#126
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From: KY
Lash is set with the up and down movement, not the turning method. Its turned a little back n forth to just keep it centered, but your going up and down until all that is out. Once all up and down is gone, this is zero lash point.
Since all have been done with the turning method, need to loosen all of them and get some oil back in them.
Since all have been done with the turning method, need to loosen all of them and get some oil back in them.
#127
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From: Malaysia
Lash is set with the up and down movement, not the turning method. Its turned a little back n forth to just keep it centered, but your going up and down until all that is out. Once all up and down is gone, this is zero lash point.
Since all have been done with the turning method, need to loosen all of them and get some oil back in them.
Since all have been done with the turning method, need to loosen all of them and get some oil back in them.
I used the wrong expression, I meant spin the pushrods between my fingers and tighten the rockers until the pushrod just canīt spin anymore to have zero lash. Then another half turn on the nut. Just by the book, but I might have made a mistake on the first cylinder.
Anyway next time I go the boat I will try to loosen it and see if thereīs some compression coming and the issue can be solved that easy.
#128
I used the wrong expression, I meant spin the pushrods between my fingers and tighten the rockers until the pushrod just canīt spin anymore to have zero lash. Then another half turn on the nut. Just by the book, but I might have made a mistake on the first cylinder.
Anyway next time I go the boat I will try to loosen it and see if thereīs some compression coming and the issue can be solved that easy.
Anyway next time I go the boat I will try to loosen it and see if thereīs some compression coming and the issue can be solved that easy.
#129
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From: Malaysia
Another lockdown, another lost month, but yesterday finally I had my big day. 10 months passed since I pulled the seized engine and it was very exciting to start my first rebuilt engine.
Adjusted the valves again and got a quite high compression around 170 on all cylinders except #7 which is at 145 psi. Good enough for now. Checked all hoses, ignition and connections again, took a deep breath and hit the starter. Fired up almost immediately, idled without throttle, didnīt make any strange noises, no smoke, no vibration, no problems. That was easy. Even the timing was only slightly off so there was actually not much to do. Let it run for a while and that was it.
Now I have two running engines. Thinking about opening the other one too, take the cylinder heads off to see if everything is ok.
Or skip it and start something new? The outdrives need attention, Iīm sure they are in bad shape.

completed engine before first start
Adjusted the valves again and got a quite high compression around 170 on all cylinders except #7 which is at 145 psi. Good enough for now. Checked all hoses, ignition and connections again, took a deep breath and hit the starter. Fired up almost immediately, idled without throttle, didnīt make any strange noises, no smoke, no vibration, no problems. That was easy. Even the timing was only slightly off so there was actually not much to do. Let it run for a while and that was it.
Now I have two running engines. Thinking about opening the other one too, take the cylinder heads off to see if everything is ok.
Or skip it and start something new? The outdrives need attention, Iīm sure they are in bad shape.

completed engine before first start
#130
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Posts: 130
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From: Malaysia
I left the country shortly after that last post above in May 2021 to escape yet another strict lockdown and what I thought would be a short trip to Europe. Instead it took me 6 months to be allowed back into Malaysia.
In the meantime somebody broke into my workshop, damaged the big roller shutter and stole some tools and parts, most notably my precious two-bank marine charger.
Took me a couple of weeks to have everything replaced and repaired, had a surveillance camera system installed and so on.
I was eager to fire up the engines, port engine hadnīt run in 10 months without any preparation whatsoever. But even with the weak battery it started immediately as did the starboard. Iīm always surprised how easy these engines start having carburator and no electronics.
With that out of the way I took the outdrives off. They are not too bad but both transom assemblies are heavily corroded to the point that I canīt even disassemble them without destroying parts. Need to find replacements. Flying them in will cost a fortune but itīs probably the way I have to go.
In the meantime somebody broke into my workshop, damaged the big roller shutter and stole some tools and parts, most notably my precious two-bank marine charger.
Took me a couple of weeks to have everything replaced and repaired, had a surveillance camera system installed and so on.
I was eager to fire up the engines, port engine hadnīt run in 10 months without any preparation whatsoever. But even with the weak battery it started immediately as did the starboard. Iīm always surprised how easy these engines start having carburator and no electronics.
With that out of the way I took the outdrives off. They are not too bad but both transom assemblies are heavily corroded to the point that I canīt even disassemble them without destroying parts. Need to find replacements. Flying them in will cost a fortune but itīs probably the way I have to go.
Last edited by musthave1; 02-14-2022 at 07:06 AM.






