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Ring catching something

C

Chad Noben

Member
69 25hp Johnson. I honed the cylinder, put the pistons in backwards, then after disconnecting them from the crank(to fix that stupid mistake) I just turned them 180 degrees while in the cylinder. Now when I push down on a piston it catches somewhere it feels like. It didn't do that when they were installed backwards. I put all the rings around that pin in the groove also. They all had a .030 gap. Any ideas on why it's doing this all of a sudden. What should I do?
 
Pull em out and inspect as it sounds like end of ring has rolled over locating pin and .030 end gap is way to much gap as .015 is maximum!!!
 
Haha! Ya my dad was helping.... But after HE told me they were in backwards. I'm gonna re measure the gap in the rings! He thought they were fine cuz they are very close to touching together. I'm just gonna rip it apart AGAIN and make sure the rings are in the same position. Don't see how they could have moved, but I guess it's possible. And no I didn't get a repair manual. I have you guys! :) I'll let u know what I've figured out. Going back to wrenching on it in a couple hrs. Any other suggestions???
 
When you turn a piston 180 degrees while still within the cylinder, you are sliding the ends of the piston rings past the ports. The ring springs outwards.... uh oh!
 
Will the end caps make it catchy cuz I noticed I had em on the opposite rods and switch em and everything was fine after that!! Weird I thought. Also which way do you put the impeller in the housing? The blades curved which way? If it happens to be backwards, will it fix itself? I'm gonna try and get a vid on YouTube tomorrow of the first start. Will let you know. Thanks again!!!
 
Actually it makes no difference which way you install the impeller. As soon as the engine turns over in the proper direction, the impeller blades will flex in the proper direction. However, if you had the housing upside down in your left hand, the normal rotation direction would be that you would want to spin the impeller into it in a counter clockwise direction.
 
For what it's worth..... In addition to my last post which pertains to the installation/rotation positioning of the impeller....

Even the most experienced outboard technician, when working on any outboard regardless of its make or horsepower, will at times encounter moments when he/she will turn the engine over backwards (counter clockwise). This might be to check for an evasive/intermitent tick, click, knock, tap, whatever, or simply to inspect some internal portion of the powerhead for example. This is nothing unusual.

Obviously, when this counter clockwise procedure is performed for whatever reason, the impeller is being turned in the opposite of its normal rotation. This creates no problem as the impeller is a flexible component which sets within a housing where the center of the impeller is offset. As such, the impeller blades are in a curved compressed position within the housing for a portion of its rotation and near fully extended for the duration of its rotation.

Due to the design of the water pump assembly as stated above, regardless of what direction the flexible impeller blades might be facing, as soon as that engine starts, the impeller blades will flex into their proper operating position.

This is assuming that the impeller was not shipped over on the Santa Maria which has most likely caused it to encounter a non flex rigor mortis like condition.
 
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