Today I discovered a problem with the air cleaner on my Universal M25XP, 1988 model.
We have been trouble-shooting a problem with the engine stumbling and shuddering at about 1300 rpm. Since it's been a while since the valves were adjusted, that was done -- they were indeed out quite a ways.
Then we removed the air cleaner with it's hose clamp that holds the base on.
I should note that the top part has been vibrating with engine shakes for many years, and I just took it as "normal" that the top part would freely rotate round n round the part where it was swaged onto the base where the clamp is.
Our mechanic said to fix this (!) -- Turns out that another boat in the moorage had some valve and piston damage from many years and hours of that same part vibrating (same engine model), and that this wore the metal to the point where some bits of the inner swaged part broke off and were ingested by the engine.
I had previously removed the whole round 'can' many years ago and washed it in thinner, and, getting little dirt out, left it alone.
Today I opened it up by removing the two long screws that hold the top on. My oh My. :0
Inside was a thick "donut" or ball of aluminum filter material. On the bottom was a fine metal screen to catch…. um…. bits of the aluminum filter media that had broken off and stuck in the mesh. Some could have worked their way through.
I cleaned up all the parts and picked every piece of aluminum shavings (which is what the stuff resembles) out of the screen.
Our mechanic sez this inner donut-shaped filter should not be there to threaten the cylinders with loose bits that work their way through it. This may or may not be a stock part for this engine. It's hard to know for sure at this point.
So now it's all clean. i peened down the inner little flange on the base so that it grips the filter-can floor tightly and no longer will turn.
The "mesh" donut is staying out. The fine screen stays in.
I have cleaned up the outside foam sound-reduction "filter" and will put it back later.
Anyhow, amazing what you can find where you never before thought to look!
Cheers,
Loren
We have been trouble-shooting a problem with the engine stumbling and shuddering at about 1300 rpm. Since it's been a while since the valves were adjusted, that was done -- they were indeed out quite a ways.
Then we removed the air cleaner with it's hose clamp that holds the base on.
I should note that the top part has been vibrating with engine shakes for many years, and I just took it as "normal" that the top part would freely rotate round n round the part where it was swaged onto the base where the clamp is.
Our mechanic said to fix this (!) -- Turns out that another boat in the moorage had some valve and piston damage from many years and hours of that same part vibrating (same engine model), and that this wore the metal to the point where some bits of the inner swaged part broke off and were ingested by the engine.
I had previously removed the whole round 'can' many years ago and washed it in thinner, and, getting little dirt out, left it alone.
Today I opened it up by removing the two long screws that hold the top on. My oh My. :0
Inside was a thick "donut" or ball of aluminum filter material. On the bottom was a fine metal screen to catch…. um…. bits of the aluminum filter media that had broken off and stuck in the mesh. Some could have worked their way through.
I cleaned up all the parts and picked every piece of aluminum shavings (which is what the stuff resembles) out of the screen.
Our mechanic sez this inner donut-shaped filter should not be there to threaten the cylinders with loose bits that work their way through it. This may or may not be a stock part for this engine. It's hard to know for sure at this point.
So now it's all clean. i peened down the inner little flange on the base so that it grips the filter-can floor tightly and no longer will turn.
The "mesh" donut is staying out. The fine screen stays in.
I have cleaned up the outside foam sound-reduction "filter" and will put it back later.
Anyhow, amazing what you can find where you never before thought to look!
Cheers,
Loren
Attachments
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Filter parts cleaned.jpg -
inner can peened.jpg -
plugged screen & donut.jpg -
screen bits.jpg -
Screen and mesh.jpg
So that is why I suggested something from the tractor world. Those filters are designed for rough environments and are very effective.
