Hi,  I got a new-to-me oil-water pump from a guy I know which I'm going to use to replace the leaking pump on my K75.  I've successfully removed the pump and cover plate from the engine block, however the impeller gear is stuck.  It won't come out with just pulling by hand. I don't want to apply any force at the moment until I confirm how it should be removed.

Question: should this part just pull out of the block or do I have to get into the oil reservoir to release it?

Hi Rob
That guy should just pull straight out - resistance is probably the o-ring.

Cheers SuziQ. I'll use more persuasion.

That thing has been living, on it's own, in the bottom of my box of engine bits for a few years now. Thing is, I have two oil/water pumps in there as well, and they are both complete with those shafts in place. Which is worrying...

Yeah. I had to use the two screwdriver trick to get the last one out. It warn't comin out not no way no other way.

I have the same issue, cannot pull the small Oil Pump gear from the the output shaft.  Has anyone used a tap and install a bolt so that a hammer can be used?  If so what size tap?  Thanks in advance for any advice!

I doubt that a tap will work as the shaft is, at the very least, semi-case hardened. Have you tried levering it off using two screwdrivers? If not, make sure you put a piece of cloth between the screwdriver and the pump housing to protect the housing.

Re: Protecting the surface of the oil/water pump housing from damage if levering it off with 2 levers such as screw drivers. 
For years I used commercially made curved plastic/rubber rim protectors with a piece of cord attached to protect wheel rims when tyre changing using tyre levers. The down side is that they cost $, quickly become damaged and have to be thrown away and are too thick, making their removal sometimes difficult. I have changed to making my own disposable rim protectors. I cut out pieces of thin wall semi hard plastic found in plastic milk and drink containers and the like. 
Consider this easy option to protect the housing surface when levering.

Dai,

That's what I was fearing...  this is all my bad...  I installed the pump assy with both gears in the pump housing...  I should have installed the small oil pump driving gear into the engine case and lined it up with the offset notches of the output shaft, then install the pump assy (with the driven larger gear installed lining the large gear up with the small gear by turning the water pump impeller).  

I've done this twice before  on this very bike (Original owner)!!!!  In this case in a time constraint hurry, thought the driving small gear was notched equally with the output shaft meaning it could only go in one way even though it could be 180 degrees either way!!!  NO!!!!  like the airheads Ignition trigger assy's the notches are offset! 

I thought during the the assembly at the time of the Oil pump/water pump went in smoothly until it matted with the engine front case, the notches must have been 180 off!!!

When I went to start the engine it cranked over and started briefly, then locked up!  Think the engine is toast!!  I have a spare with 25K Miles on the clock, this one has 310,000 (but still going strong until this debacle)!!!!

I work as a Aircraft Mechanic and cannot believe I did this!!!   And I know better.

Moral of the story!!!  I was in a hurry to get this little job done as we have our national rally in Oregon this coming week..  wanted to ride the bike up  and tried to fit this job into a tight work schedule!!!

I've been beating my self up these past few days mentally on how this could have been prevented, however, looking forward now to do the engine swap after the rally and will "Take my Time" Slow  and methodical is good!!!

Taking My modified 1986 R80 to a 100RS to the rally.  It will be cooler ride however...  which is a very small benefit of this man induced disaster (in my head of course)!!  

Don't be so uppity that a simple job can be done in a hurry!!!

The pump might be toast but I doubt that the engine is. Drain the oil and coolant, pull the pump and see if the engine will turn over.

Now, which airline do you work for...?  

My guess is FBO? What are you qualified on? I used to fly GAT-115s (hi Aussies!) and PA-140s until I had an unwanted high-speed meeting with the asphalt in the 1980s.

acftfliehr wrote:thought the driving small gear was notched equally with the output shaft meaning it could only go in one way even though it could be 180 degrees either way!!!  NO!!!!  like the airheads Ignition trigger assy's the notches are offset!

I thought during the the assembly at the time of the Oil pump/water pump went in smoothly until it matted with the engine front case,

I don't see how you could get the pump to mate up and bolt with the engine at all if the problem were as you describe. The pump would be standing off from the case by the length of the pump gears's stub shaft that should have entered the engine output shaft but was instead hitting the edge of the output shaft's opening because the notch was out of synch with the slot.

If it's any consolation, the whole pitch of your distress makes me believe that you're mistaken, mainly because I've performed a few of those self-recriminating melodramas, too. I've abandoned them as diagnostic tools because the solutions always came from different and more benign directions. 

Maybe the source of the problem is actually within the pump. You didn't drop a nose ring into the oil pump gears during reassembly, did you?

All Thanks for your support on this issue...  Will not work on this until 2 weeks as off to the the rally tomorrow..

Laitch, it did seem to mate up perfectly as I was turning the gears until it matted...  However....  the starter actually won't turn the motor over and the engine was seized, the driving gear is freaking stuck solid to the output shaft.  Tried some pretty aggressive techniques minus tapping for slide hammer use.

DAI, Started under my dad overseas 1964 to 1974 (India, Iran and Afghanistan) on Convair embassy aircraft (C-131's as a cleaner then third wipe) came back to the states in 1974 became a B-52 Crew Chief, got out after 4 years and after A&P school, tried to get in the airlines, but went the corporate route...  Jet Stars, DH-125's Falcons, then DOM duties on Falcons, and Gulfstreams...  to this day...

Learned how to ride in Afghanistan 1972...  Honda CD90...  Wow that is years ago!!!  Guys thanks for all the support don't do stupid stuff like I did!!!

If the engine is seized in both directions, I'd empty a can off Freeze Off on the face off that gear and go have a piece of Key Lime pie.

Enjoy the rally!

I am watching this with interest. I have a complete rebuilt oil/water pump on its way to me for my K100 Sprint.

My plan is to 'simply take the old one off and put the new one on....' then refurb the old one as a spare for my RS.

I am not naive enough to believe it will be that simple...........but am hopeful.

The first time you do a pump rebuild, you will bugger up the seal. The next time you do a pump rebuild, you will remember that buggered up seal and will proceed to get it right every time thereafter.

-Confuscious