plastic gear on 200 h.p. Mercury xri

moffett cr.

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How often does the plastic gear on crank need replacing ? How many hrs. can it normally last? Is their an up date or any options? Is this something a person can do (with some mechanical exsperiance)? The motor is a 1995 Thanks GT
 

Dukedog

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Re: plastic gear on 200 h.p. Mercury xri

Questions for you. Do you know tha history of this motor? Having any kinda problems with tha oiler stuff?

Yes, it is a major deal to replace/service. Motor is "almost" a complete teardown to get to it.
 
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moffett cr.

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Re: plastic gear on 200 h.p. Mercury xri

Questions for you. Do you know tha history of this motor? Having any kinda problems with tha oiler stuff?

Yes, it is a major deal to replace/service. Motor is "almost" a complete teardown to get to it.

Thank you Dukedog, I just bought the boat and read a thread about gear troubles. Just thought their might be some prevention before something did happen. Thanks GT
 

Dukedog

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Re: plastic gear on 200 h.p. Mercury xri

Reason I asked 'bout tha history! Tha thing 'bout tha oiler gear problem is way over rated. All ya gonna hear 'bout is tha ones that do give up. Usually by an owner that doesn't know better or simply doesn't care about how its taken care of. Ya not gonna hear 'bout tha thousands that are still kickin'. Merc/Mariner would not stay with tha same "basic system" for 20+ years if its bad. One that age and no history known to ya, probably best ta go ta pre-mix and do away with it so ya can sleep at night. Tha main reason for failure of tha gear is heat. A severe over heat one time can do it damage right then. Several slight over heat problems will take a toll with it eventually goin' south. This not ta say that's your case but without knowin' for sure!!!.........jmo
 
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Kvon

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Re: plastic gear on 200 h.p. Mercury xri

Bought a new 1991 200HP Merc -- babied it its entire life and as I watched the hour meter turn 700 hours the piston came out the side of the block. Replaced it with a new 2002 200 hp and got 12 hours on that engine before the plastic drive gear for the oil injection pump stripped out and cooked the powerhead. Got that replaced under warranty and make it all the way to 230 hours before it happened again. I'm a Yamaha guy now.
 

sam am I

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Re: plastic gear on 200 h.p. Mercury xri

Ran a 92 175 (original owner) almost yearly, normal use, never over heated, just tore it down this fall,(not oil pump related) gear is perfect........ :juggle:
 
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Dukedog

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Re: plastic gear on 200 h.p. Mercury xri

Like said, "ya only hear 'bout tha bad ones". They're ALL mechanical no mater what color they are................
 

sam am I

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Re: plastic gear on 200 h.p. Mercury xri

I wonder though....seems that in looking at it, the components as I tore it down, the pump and/or bushing/s and/or drive shaft would have to have locked up to strip/melt those teeth.

Seriously, the drive shaft essentially just floats on the plastic gear while free spinning in its bushing, the drive shaft then is just keyed into the face of a worm gear in the pump. The only resistance should be friction in the bushings and the back pressure from pumping oil. Those bushings went dry somehow or the pump broke apart inside and locked the pump up. I guess that doesn't help, it failed regardless but, I'm stumped (not hard to do) with how they fail when they're so simple.

Even heating the "plastic" PHENOLIC, whatever to where it's so brittle, if you dropped it it would shatter, with such little back forces here (I never measure it, just assuming based on tearing it down), the reports of it melting and striping sound like it's (the pump or drive component/s) are locking up to me.........the gear is just the effect, not the cause...JMO, again.

But I'm so paranoid now, I'm instrumenting the whole damn thing and running a out of range signal into the low oil circuit!!!
 
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Dukedog

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Re: plastic gear on 200 h.p. Mercury xri

.........the gear is just the effect, not the cause...JMO, again.

Tha VERY few I've actually seen and ones I've talked ta other people about. Tha pinion was still "free" but tha ring gear was broken.........
No mater its up ta him as to what he wants ta do with it...........
I would think, if its an older motor and you could eliminate a possible future problem with a LITTLE inconvenience so be it.......... jmo
 

sam am I

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Re: plastic gear on 200 h.p. Mercury xri

Tha VERY few I've actually seen and ones I've talked ta other people about. Tha pinion was still "free" but tha ring gear was broken.........
No mater its up ta him as to what he wants ta do with it...........
I would think, if its an older motor and you could eliminate a possible future problem with a LITTLE inconvenience so be it.......... jmo

Ahhhhhhhh, so those gears just broke....that's different then all the other horror stories of stripping/melting etc.......hmmmm. I suppose I could buy that, shock (expansions/contractions and the like) could certainly just cause it to break into pieces, well hells bells, i might have hair lines in mine.....GASP!!!

I recall back in the day, Chevy used a phenolic timing gear (was phenolic coating on top of the steel timing gears) on my 350's 327's and such. To limit noise I believe. Those were always breaking but that was due to shear force of the timing chain on the crank, they soon went to just steel.........I'm still fighting the mixing............I'll mill out a metal gear if I have too!! :rolleyes:
 
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Dukedog

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Re: plastic gear on 200 h.p. Mercury xri

Stripped, melted or broken gears.. BROKE is broke. All definitions are included!............Tha pinion was still free.
 

moffett cr.

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Re: plastic gear on 200 h.p. Mercury xri

Thanks ,so should i fix what is not broke or go for it? I'm not reel good with a paddle
 

boobie

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Re: plastic gear on 200 h.p. Mercury xri

First time I read about the plastic gear but heard of it some years back. O' Well, OMC has the VRO. Just wondering when these manufactures will smarten up and stop useing CPS ??
 

wired247

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Re: plastic gear on 200 h.p. Mercury xri

To answer your question you can do it yourself but it requires pulling the powerhead and pulling the block apart. Probably a good time for a inspection and re-ring. Its a good long weekend job.

I like the oil injection on low performance motors. I wouldnt spin one over 6K for very long though. Its just much easier and more confidence inspiring to use pre mix on go fast motors. I try to stop being a go fast guy every now and then but it never sticks.
 

moffett cr.

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Re: plastic gear on 200 h.p. Mercury xri

Any idea what it would run to get the gear replaced? Thank for all the info.
 

wired247

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Re: plastic gear on 200 h.p. Mercury xri

Its just short of an engine rebuild. Probably cost quite a bit to get a shop to do it.
 

Dukedog

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Re: plastic gear on 200 h.p. Mercury xri

Thanks ,so should i fix what is not broke or go for it? I'm not reel good with a paddle

If it were mine, I'd lose tha oiler stuff, idle stabilizer then just pre-mix.............Has tha thing hada check up? ie: comp. electrics etc?
 

sam am I

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Re: plastic gear on 200 h.p. Mercury xri

Grain of Salt...

"A common failure. The metal worm gear heats up and then the plastic crankshaft teeth are melted,and wiped.Mercury did a recall about the top bushing it was reduced in size,so it would not expand too large and create drag by binding against the hole in the block, but the part number remained the same.The new bushing was identified by a symbol on the flange end.I have a replacement Quicksilver engine,that was replaced under warrenty(becase of the problem),and it wiped the crankshaft gear again.The cause was the top bushing was not changed when new engine was installed.

Mercury is well aware of the problem,there solution in later years is to delete the rotation pickup alarm on the oil pump that sounded and announced the oil pump drive failure(mainly not in time to advoid problems),so now you don't know about the failure until the engine seises up and stops cold.

The problem is in the 2.5 liter V6 line."

:facepalm:

{{{{Runs to check symbol on bushing flange}}}} Sry moff........Maybe a direct call to Merc is in my(your) near future.

IF and I mean IF, I have no clue, I'm just reporting the news.....heat expansion is in fact stopping the drive gear(maybe some but not all), perhaps by the time a guy can get his hands on the things, it's cooled down and rotating freely, thus masking itself....yes broke is broke, pre-mix and be done, agreed.

Would be nice to know though if there is just one failure mode or two or three......Dog reports one type, this guy reports another, both seeming reasonable.

I have done some research and seem to hear more of stripping/melting mixed in with bits and pieces of teeth everywhere type....indicating(IMO)a locking(heat expansion induced evidently) up by the drive gear. Perhaps a sudden locking up snaps the gear into pieces as well....IDK.
 
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Dukedog

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Re: plastic gear on 200 h.p. Mercury xri

Seen a whole bunch a "bulletins" and recalls over tha years but if that's one, it musta slipped by me. Merc has never changed a part and not tha number that I know of. Where did ya get that information?

Reread your post again and a little confused 'bout this part.

".Mercury did a recall about the top bushing it was reduced in size, .so it would not expand too large and create drag by binding against the hole in the block,"

Tha top isn't a bushing anyway. Its a bearing............
 
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sam am I

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Re: plastic gear on 200 h.p. Mercury xri

Copy and paste, got it off another web site.....shhhhhhhh.........So, I have no clue how legit it is but, same here as well, take these things with a grain of salt. The guy is a senior member for what it's worth. Nobody beat him to death over what he wrote/states...

He reported thou...."but the part number remained the same"

Mine is a bushing, just looked w no symbol :yield:

SAM_3555_a.jpg
 
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