Purchased a replacement oil pump from mikes and installed it. Problem is, I can't turn the pump by hand. With all the parts back on, I thought I should be able to turn the large gear manually. Is this normal? Are the replacement parts that much tighter? Granted the old pump had an unknown amount of miles and turned easily. I don't want to start the engine and shear the pump shaft pin.
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pcoumbe
BicolXS650
Sounds to me like you may want to read the NOS oil pump section of this thread then remove your pump again before turning your engine over.
http://www.xs650.com/forum/showthread.php?t=2426
http://www.xs650.com/forum/showthread.php?t=2426
The article there is for a mod on the stock oil pump. This increases the volume of the stock pump.
If you have bought a new one off Mikes then do some research, i have a vague notion there is a thread on this. ??????????
If you have bought a new one off Mikes then do some research, i have a vague notion there is a thread on this. ??????????
Brian902
XS650 Junkie
XSJohn may not be a literary genius but he sure new his stuff about the XS650.
Leo
Leo
I did the same replacement for the other 650, without having this problem. Knowing the cases on both bikes are 30+ years old, I am wondering if the other case is worn. The rotor is steel, the case aluminum, wear should be on the case more than the rotor. The other bike has an oil pressure guage so I am not worried about the case being worn out and causing a flow problem. Now I also wonder how close of a tolerance the replacement rotors are compared to an OEM or the other one that I purchased from Mike.
Dug through my box of spares and found another mikes rotor. It is new and just as oversized as the other recent purchase. Also found a spare oil pump cap. I now have two oversized rotors that will not fit into the caps. Compared to what I believe is a genuine Yamaha rotor there is a significant difference in all dimensions. I guess the only fix is to fit the rotor by modifying the cap. That is not a smart repair. Changing a hard to find part to fit a cheap part. To bad the only available source is so far out of spec.
Brian902
XS650 Junkie
Modifying the cap would be my last choice.
Can the new pieces be re-sized?
Or ask members here for a good used replacement?
Can the new pieces be re-sized?
Or ask members here for a good used replacement?
After another search found an OEM at Cheap Cycle Parts. More expensive but worth having just to compare the parts. Will measure the various parts and let everyone know. Getting a used part is no better than one that doesn't fit. You won't know what problems might happen until the bike is on the road.
New OEM rotor assembly available at boats.net for $40
New rotors seem to be out of stock everywhere. In the computer age there is no excuse for any company to not list available inventory on the information page. Until then I think I might try to fit the out of spec part from Mike's. Will try my bench mounted horizontal sander to thin the rotor down to spec. At this point I don't have anything to lose. I am surprised there are no past posts on this subject. I looked through about ten pages with no luck at all.
Been 40 years, memory on this a little fuzzy. My XS1B had the original pump. Friend at Yamaha shop mentioned upgraded pump, a little bit wider (I think it went from 6mm to 8mm), pumps more oil, supercedes older pump (XS1), plugs right in. Sounded good, swapped out pumps, donated original to our 'salvage parts' shop.
The parts books show the two pumps, the first/original had the pressure relief on the pump body, later units used pressure relief in filter body.
There's a short reference to it in this thread: http://www.xs650.com/forum/showthread.php?t=72
Long thread, try thread search for the word 'relief'....
The parts books show the two pumps, the first/original had the pressure relief on the pump body, later units used pressure relief in filter body.
There's a short reference to it in this thread: http://www.xs650.com/forum/showthread.php?t=72
Long thread, try thread search for the word 'relief'....
Last edited:
In my 70-74 Factory manual it has technical bulletins in the back. It has one about oil pumps. They upgraded the oil pumps on the XS1's It doesn't spec just what was done but it has to be replaced as a unit. No mixing of old and new parts.
The new pumps started with engine number 004130.
I think TwoManyXS1B's has the specs right. The rotors are thicker, may be slightly large diameter too.
Leo
The new pumps started with engine number 004130.
I think TwoManyXS1B's has the specs right. The rotors are thicker, may be slightly large diameter too.
Leo
A lil' thread update to address this issue of binding MikesXS pump rotors.
Another relevant thread:
http://www.xs650.com/threads/mikes-xs-oil-pump-rotors.16545/
The OEM rotors should measure right at 8.00mm (0.3145").
On receipt of new rotors, you MUST measure the diameters and widths.
My measurements showed slightly thicker rotors. This is both a good thing and a bad thing. Bad, if you just plop them in there and install. The pump may bind and not rotate. However, it can be a good thing since the rotors can be easily lapped to a desired thickness, perhaps leaving them slightly thicker to reduce the side clearance.
Measurements of my rotors:
The outer rotor was 0.0025" oversized in thickness, the inner was 0.001" over.
Easily solved by lapping with #400 wet-or-dry on a flat plate. Occasionally spray some brake cleaner on all that to help with cutting and preventing load-up.
Using an orbital motion with medium pressure, make about 3-5 sweeps, then rotate the part about 90°, another 3-5 sweeps, continue. Do both sides, and occasionally measure all about to ensure that the thickness is consistent. It only took me about 2 minutes to knock off 0.002" from the outer's thickness, much less to knock off 0.0005" from the inner.
That left the new rotors with smooth lapped sides, and a finished width of 0.3150" (8.05mm).
Just enough extra width, 0.0005" (0.05mm) to bring the side clearance back to spec.
Interestingly, the outer rotor has a slightly concave/dished shape on one side. And, that is the side to do most of the lapping. This pic shows the lapped surface that appears about the edge of the outer rotor.
The assembled oil pump now spins freely...
Another relevant thread:
http://www.xs650.com/threads/mikes-xs-oil-pump-rotors.16545/
The OEM rotors should measure right at 8.00mm (0.3145").
On receipt of new rotors, you MUST measure the diameters and widths.
My measurements showed slightly thicker rotors. This is both a good thing and a bad thing. Bad, if you just plop them in there and install. The pump may bind and not rotate. However, it can be a good thing since the rotors can be easily lapped to a desired thickness, perhaps leaving them slightly thicker to reduce the side clearance.
Measurements of my rotors:
The outer rotor was 0.0025" oversized in thickness, the inner was 0.001" over.
Easily solved by lapping with #400 wet-or-dry on a flat plate. Occasionally spray some brake cleaner on all that to help with cutting and preventing load-up.
Using an orbital motion with medium pressure, make about 3-5 sweeps, then rotate the part about 90°, another 3-5 sweeps, continue. Do both sides, and occasionally measure all about to ensure that the thickness is consistent. It only took me about 2 minutes to knock off 0.002" from the outer's thickness, much less to knock off 0.0005" from the inner.
That left the new rotors with smooth lapped sides, and a finished width of 0.3150" (8.05mm).
Just enough extra width, 0.0005" (0.05mm) to bring the side clearance back to spec.
Interestingly, the outer rotor has a slightly concave/dished shape on one side. And, that is the side to do most of the lapping. This pic shows the lapped surface that appears about the edge of the outer rotor.
The assembled oil pump now spins freely...
