25hp Lots of ? Need some help

[Gamblerman]

Ok Ill start with I got a motor for cheap. When I got the motor the guy told me it ran but the last time he had it out it overheated on him on his way back to the dock .He let me know that he shut it down and trolled back and didnt run the motor. Ok so now I get the motor from him but he at one point had the lower unit of to change the water pump propeller and never got back around to putting back together. Well I have what I think is most of the parts but I feel something is wrong .I have changed the water pump on my bigger outboards but never had a smaller motor so Im a little lost. My ? is in the shaft that the propeller mounts to there should be a key and a flat spot on the shaft to hold the propeller but this one only has a pin that looks like it was broke off in the shaft but the propeller itself has a keyway so Im up in awww with this.Now I did run it for a second just to see if it ran.This is a super clean motor and I would have to say it maybe a 1983 1984 model but cant find any on the motor or mounts so if anyone can fill me in that would be great.

 

[Jim Hawkins]

Re: 25hp Lots of ? Need some help

Why not just pull up a parts diagram for your motor online and compare parts?

 

[Gamblerman]

Re: 25hp Lots of ? Need some help

I did just that but I don't see a spot for the key on the shaft . There is only a pin.I have never seen this before.In the diagram or any kit I look at it has a key way .

 

[Gamblerman]

Re: 25hp Lots of ? Need some help

I can look up the motor because i don't see any number unless someone know if there is a spot on the block that may have the number to look up info for this unit.

 

[Will Bark]

Re: 25hp Lots of ? Need some help

Look for a silver welch plug on the block it is supposed to have the serial # at least; you can call BRP with # and they are supposed to be able to tell you what model engine you have. Good luck

 

[HighTrim]

Re: 25hp Lots of ? Need some help

Just a little terminology issue here. I believe you are referring to the impeller, not propeller. The impeller is what cools your motor. The propeller pushes the boat. Different shafts, different keys etc...

So, for the impeller, there were different methods used for keying it. I just did a '84 25hp the other day, and it did have a half round key with a flat spot on the drive shaft. Maybe someone swapped shafts?

 

[steelespike]

Re: 25hp Lots of ? Need some help

I did just that but I don't see a spot for the key on the shaft . There is only a pin.I have never seen this before.In the diagram or any kit I look at it has a key way .

My aftermarket ser. manual indicates motors prior to 85 use a pin to drive the impeller.
Also for reference the gear case is a 2 piece prior to 85.85 on is a thru hub exhaust.with a one piece gear case.
Also for reference 79-84 use the same impeller 18-3051 Sierra number.

 

[AlTn]

Re: 25hp Lots of ? Need some help

as info..last time I called Bombardier I was told that they could not cross match model no. w/ serial no. as OMC did not keep keep this info....might have just been a "blow off", don't know, disappointing to hear tho'

 

[racerone]

Re: 25hp Lots of ? Need some help

If cowling is original ( not painted ) it will be easy to pinpoint the year.---Post a bunch of pictures of this motor.

 

[Gamblerman]

Re: 25hp Lots of ? Need some help

Thanks for all the info and sorry I didn't realize I was typing propeller and not impeller must have been a blonde moment lol.

 

[HighTrim]

Re: 25hp Lots of ? Need some help

as info..last time I called Bombardier I was told that they could not cross match model no. w/ serial no. as OMC did not keep keep this info....might have just been a "blow off", don't know, disappointing to hear tho'

They can get a year from a serial number alone.

 

[Jim Hawkins]

Re: 25hp Lots of ? Need some help

How about a picture of the driveshaft where the impeller goes including the (broken?) pin?

 

[oldboat1]

Re: 25hp Lots of ? Need some help

There are some impellers that have a keyway slot that runs the full width(?) of the hub, and some that stop halfway (presumably, to be used with a pin). I have always used the impeller for the model I was working on, usually after-market. The last motor I worked on was a Chrysler sailor with a pin style key, but the impeller for that model came with the full slot (as if for the other kind of shaft key). As far as I can tell, there is no functional difference in impellers where the key slot is concerned. There is no vertical movement of the impeller on the shaft, so pin style key will remain engaged.

The main issue for you seems to be a broken pin? Is there any way you can grip it, perhaps with a vice-grip? It might be that too short a key was used (not broken, but inserted too far into the shaft) -- might have happened if a pin for a smaller diameter shaft (smaller hp) was used in a larger diameter shaft. But I'm guessing here. First thing to do is grip and pull or drill out the pin, and replace it with a correct one. It's probably heresy, but I don't think it matters whether the replacement pin is a piece you come up with or is provided in a waterpump kit for your model. In other words, as long as the piece you use is the right diameter for the shaft hole and is long enough to lock in the impeller, you should be good to go.

 

[AlTn]

Re: 25hp Lots of ? Need some help

thanks, High

 

[HighTrim]

Re: 25hp Lots of ? Need some help

thanks, High

I have the serial numbers tracked for both American and Canadian motors up to a certain point. Don't have anything too new, as I don't care about them.

 

[oldboat1]

Re: 25hp Lots of ? Need some help

so...you have the ser. number, but not the model number? You called Bombardier to ask about a serial number match, but you don't have the number?

Like Racerone says, pics would probably help. If you have or think you have the serial number, post it.