Need advice on purchase

[the daydreamer]

if owner says over 200 on each cyl he is blowing compression up someones A** !!!!! i am like spare 90 to 120 is what they will be!!!!

[Larryrsf]

Originally Posted by spareparts

if that engine has 200 psi on the compression test, someone is lying or needs a new compression tester(should have been in the 120 range). I'm not a big fan of those engines although some people like them. Keep in mind, they were not made for very long , have a history of corrosion issues, and a lot of engine components are no longer available, from any one. i wouldn't have gone any higher than $5000. I'll go ahead and fly the flag on this one

My factory-trained mechanic said the compression numbers should be within a few pounds of each other-- which is more important than the number itself. He declared my old Evinrude 150 in "new" or recently overhauled internal condition with compression just over 100# in ALL 6 Cylinders. If one had been several pounds lower, that would have indicated problems with rings or valves, etc.

Larry

[THEFERMANATOR]

Originally Posted by Larryrsf

My factory-trained mechanic said the compression numbers should be within a few pounds of each other-- which is more important than the number itself. He declared my old Evinrude 150 in "new" or recently overhauled internal condition with compression just over 100# in ALL 6 Cylinders. If one had been several pounds lower, that would have indicated problems with rings or valves, etc.

Larry

Ideally you want all cylinders within 5% of each other, but 10% is considered accepteable. You also want to make sure they are within a certain range though as I have seen engines wore slam slap out have compression with 2% of each cylinder, but were shot internally. Had a V4 with all cylinders at 60, but a good engine like it should have been at 115-120. Turns out it had standard pistons in a .020 bore engine. When I finally got it to run, it rattled like a metal can filled with rocks.

[spareparts]

Originally Posted by Larryrsf

My factory-trained mechanic said the compression numbers should be within a few pounds of each other-- which is more important than the number itself. He declared my old Evinrude 150 in "new" or recently overhauled internal condition with compression just over 100# in ALL 6 Cylinders. If one had been several pounds lower, that would have indicated problems with rings or valves, etc.

Larry

what your factory trained mechanic told you is true, the % between the cylinders tell more than the actual numbers them selves. But when I see compression numbers on a 2 stroke so far out of range that they can't be realist, I usually call BS on the numbers

[Big-G]

I may have mis- spoken when I said 200 on each cylinder. The seller gave me the numbers but I was more interested in his comment that compression was okayed by his mechanic. Either way I am no longer interested in the boat and motor. I would offer $ for the boat and trailer, however.

[spareparts]

Ferm, what years were those engines available? I didn't think they were around that long. Did Bomb continue to build them in carb form?

[THEFERMANATOR]

Originally Posted by spareparts

Ferm, what years were those engines available? I didn't think they were around that long. Did Bomb continue to build them in carb form?

OMC came out with the 60 degree looper in 90 for the 91 model year, and BRP kept them around under the JOHNSON name until 04 carbed when emissions completely phased them out. Throughout that whole run they were basically unchanged internally from what I have found. They were one of OMC/BRP's longest production run engines without major changes to them like the V-6 loopers got(small bore for 2 years, standard large bore for 4 years, and then switched over to the lightened and choked finger ported engines for about the last 8 years). The only other engines I can think of that had a longer run largely unchanged would have been the 3 cylinder loopers(probably the longest running engine without major changes of ANY manufacturer), or the 2.0L MERCURY's. It should also be of note the 150/175 FICHT engines were basically the same engine internally, and I believe even the current 150/175/and small block 200 has it's roots going back to that first 60 degree looper.