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New Member - 95 Mariner 25 Problem

S

Spoiled Daddy

New member
Hello to all. New to the forum and of course, have my first question.

Just bought a 95 Mariner "Marathon" 25HP 2 stroke motor to put on a 15' Smokercraft Alaskan (aluminum) boat. Starts right up, spits water and shifts appropriately while on the motor stand. After servicing the motor, I put it on the boat and tried to do some fishing. It will go into forward gear at idle speed, but as soon as any throttle is added, the prop slips out of gear and the engine races. As soon as it goes back to idle speed, it goes back into gear. Works fine in reverse, just not in forward gear. No gear grinding sound, just slips in and out of gear when any torque/throttle is added in forward gear.

When I serviced the motor, the lower unit fluid looked good (ie; no water contamination), but the drive shaft and prop assembly was completely free of any lube products and dry, but it pulled apart OK. When off and in forward gear, I can turn the prop. When in reverse, it will not turn. I don't know if this is normal or not, because I haven't owned a two stroke or worked on one in years.

I've pulled the prop, thrust hub assembly and drive shaft. All the teeth look good in comparison to pictures of parts available.

Any suggestions? Forward gear assembly maybe gone? This is not my first Mercury/Mariner 2 stroke, but the first time I've encountered this problem.

Thanks in advance for any help. Tom
 

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Sounds like the rubber hub in the prop is slipping----------Cheap and easy to mark the prop and hub and see if marks move.----Or try another prop.
 
Racerone,

Do you know if I should be able to move the prop (while the engine is off) in forward gear by hand, but not in reverse? The prop that is on it is chipped, but not beat up badly, on all three blades. I will mark it as you suggested, give it a try at the local marina and see if it is slipping.

Thanks
 
I marked the hub and test ran the motor today. Same results. Checked the lower gear case fluid and it is still ok with no obvious metal shavings in it.

Any other suggestions?
 
Hi, just a few items , you said you had leg off , ?

When you replaced leg did you ensure shaft was in nuetral , leg out.

When gear lever is in neutral , place to gether ,

When i did mine 25mariner 4st , i had similiar problems,

i found that the clip that connects to the gear shaft was not connecting properly at the top of the motor, (difficult to see)

Maybe this might be clue

Going Again.!
 
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