I am new to posting but have learned alot form reading over the past year. Here goes:
We have a 1968 merc1000 (100 HP in line 6) ser #2837868 which has been a great motor since we fixed it up last spring. The top cowl says its a BP but it has a regular tiger block and lower unit - so we think that's probably just a red herring. It hadn't run in a few years, but we did a carb job, got it to pee, and made a few other small adjustments and it ran hard all summer - once or twice a week fishing or skiing.
This is a "TIGER" block. Compression was 135 - 140 in all 6 cyinders. It ran at around 5100 rpm on the top end, like I said with no issues all last summer.
On our last trip up to Alton Lake - I still remember it well - it was a sunny fall day - tha day of the Notre Dame/Michigan football game - the boys and I were cruising around nicely when all of a sudden then engine "clanked" a few times and stopped. We tried once to start again and it moved a little but then "froze". We thought we had perhaps thrown a rod. We were towed in (across the main channel and around some barges, but still listening to the football game of course) by the "AVEC" (Alton Volunteer Emergency Corps) who are great guys and gals, but I dont' want to make a habit of calling them if you know what I mean.
Well, we ran our spare motor (a 1968 650) the rest of the fall, but I finally got around to taking off the flywheel, removing the power head, and opening her up today.
The top 5 cylinders were fine and the psitons slid right out. But the bottom cylinder had these small - about 1/4 inch -cylindrical shaped things which were falling out of the spark plug hole, and it was tough to get out. When we did get it out - these little cylinders were all melted onto the piston and some actually embedded into the piston and cylinder wall - WOW! (See pics.)
I have since figured out that these appear to be the "bearings" (like ballberings but cylindrical) which go around the end of the piston which attaches to the crankshaft - somehow these little bearings must have popped off and then got sucked into the cylinder to do their damage. The rings were basically all gone and in chunks. The piston arm (rod) has alot of play on the shaft and is missing these little bearings.
Of course, my questions are
1. How? (there seemed to be a slight difference in the cylinders as far as amount of lube - but the top 5 pistons were sliding nicely when I took them out. Could a lean bottom carb somehow cuase this?)
2. Is this repairable, and if so, how would you go about fixing - this, at least to my untrained eye - seems to have been a good strong block - so if this type of damage is repairable by re-boring or otherwise repairing the cylinder wall and then getting a new piston and rings, etc. I guess it might be worth it. I would really like to try as this motor was our first real project and it was alot of fun for me and the family.
Any help from experienced merc guys and gals is greatly appreciated!
We have a 1968 merc1000 (100 HP in line 6) ser #2837868 which has been a great motor since we fixed it up last spring. The top cowl says its a BP but it has a regular tiger block and lower unit - so we think that's probably just a red herring. It hadn't run in a few years, but we did a carb job, got it to pee, and made a few other small adjustments and it ran hard all summer - once or twice a week fishing or skiing.
This is a "TIGER" block. Compression was 135 - 140 in all 6 cyinders. It ran at around 5100 rpm on the top end, like I said with no issues all last summer.
On our last trip up to Alton Lake - I still remember it well - it was a sunny fall day - tha day of the Notre Dame/Michigan football game - the boys and I were cruising around nicely when all of a sudden then engine "clanked" a few times and stopped. We tried once to start again and it moved a little but then "froze". We thought we had perhaps thrown a rod. We were towed in (across the main channel and around some barges, but still listening to the football game of course) by the "AVEC" (Alton Volunteer Emergency Corps) who are great guys and gals, but I dont' want to make a habit of calling them if you know what I mean.
Well, we ran our spare motor (a 1968 650) the rest of the fall, but I finally got around to taking off the flywheel, removing the power head, and opening her up today.
The top 5 cylinders were fine and the psitons slid right out. But the bottom cylinder had these small - about 1/4 inch -cylindrical shaped things which were falling out of the spark plug hole, and it was tough to get out. When we did get it out - these little cylinders were all melted onto the piston and some actually embedded into the piston and cylinder wall - WOW! (See pics.)
I have since figured out that these appear to be the "bearings" (like ballberings but cylindrical) which go around the end of the piston which attaches to the crankshaft - somehow these little bearings must have popped off and then got sucked into the cylinder to do their damage. The rings were basically all gone and in chunks. The piston arm (rod) has alot of play on the shaft and is missing these little bearings.
Of course, my questions are
1. How? (there seemed to be a slight difference in the cylinders as far as amount of lube - but the top 5 pistons were sliding nicely when I took them out. Could a lean bottom carb somehow cuase this?)
2. Is this repairable, and if so, how would you go about fixing - this, at least to my untrained eye - seems to have been a good strong block - so if this type of damage is repairable by re-boring or otherwise repairing the cylinder wall and then getting a new piston and rings, etc. I guess it might be worth it. I would really like to try as this motor was our first real project and it was alot of fun for me and the family.
Any help from experienced merc guys and gals is greatly appreciated!
