HP Oil Pump from Mike's

[Spockwerks]

Guys,

I've ordered a high output oil pump from Mike's XS, you can easily reference it if you like. It is on his sight under "engine" then "oil pump". They show the standard pump first, then this one that reputes to put out twice the volume.
Does anyone have any first hand knowledge of this product? I am sure the fit and finish are up there with the standard of fabrication. What I am wondering is can I keep the tach drive (I don't want to) But if it does not need the tach gear to hold the pump gear on won't the pump gear interfere with the crank gear and result in the destruction of everything? They still need to line up properly.
Maybe I should find a good reference point and measure the height of the stock gear and pump first. Then shoot for that with the new assembly.
And how about blowing seals?
Believe me, ANY input about this mod will be appreciated.

 

[XSLeo]

I can't say I have run one. But from what I understand the housing fit under the tach drive, this allows you to run the tach.
There are two gears on the oil pump. One is the gear driven by the engine. The other gear drives the tach shaft.
The oil system gets a bit if pressure on first start up on a cold engine, It may be as high as 12-15 lbs. After it gets warmed up this drops to zero.
With the HP pump the cold pressure may be more, once warmed up I don't think it will read much higher than the stock pump. There are a few places oil pressure gets near a seal. This is in the transmission. Oil gets pumped in between the seal and the bearing. The bearings are roller bearings. This type of bearing won't hold oil well enough to build pressure. So I doubt a seal will be damaged by the extra volume of the HP pump.
From what I've read there isn't much need of the extra oil. Racers have raced these bikes for years with stock pumps with no failures because of it.
A lot of us check the clearances of the pump. We can't do much with the rotor to rotor clearances but the side clearance we can. With the two rotors in the pump body, use a straight edge along the body and use a feeler gauge to check the clearance between the straight edge and rotors.
In my pumps the clearances I found was that the thinnest feeler in my gauge set would just fit with one rotor and wouldn't fit the other. So my clearances were .0015 or better.
I don't recall the rotor to rotor clearance.
I'm not worried about my oil supply I think it's more than good enough.
Leo

 

[gggGary]

Once you get it you should check clearances like Leo did on his. There were several older threads where the new parts were binding on the housing and that created problems.

 

[Jack]

Your not gonna push any more volume of oil through the pre-jetted oil jet orifices that are in the case's with that pump,if anything higher pressure would be created at those points IMO.

 

[angus67]

The check valve behind the side sieve decides the pressure, and what ever the pressure is coming out of the jets that squirt the crank, is already maxed out. Just go stock. Too many have had probs with the hp pump.

 

[CDNTX650]

Even the regular replacement from mikes was a pos. Stock is the way to go.

 

[angus67]

I didn't even check my pump other than clean it out when I rebiult my 1980. Sprays oil everywhere with out the valve caps on.

 

[CDNTX650]

I reclearanced mine. But I'm sure it was fine before. Wasn't way out of spec.

 

[Spockwerks]

The reason I am doing this is partly superstitious, what I mean by that is I have no scientific data to prove a need for more oil flow. I have been wanting to try this out for a very long time and now the opportunity presents itself. I do believe the more oil the better in our case.
A roller element bearing like the ones we use do not require high pressure, that could even be detrimental causing the rollers to skate rather than roll and that creates damage. High volume is another story as it promotes heat transfer away from the bearing, It is more likely to flush out contaminates that our bearings are highly susceptible to, and it increases the rate of filtration, something the spin on filter guys will relate to.
Here in New Jersey a 100mi high speed ride @100*F returned an oil temp of 220*F. No need for an oil cooler, but I do use synthetic oil just in case of getting stuck in traffic or whatever. We plan to move to Florida in a few years so I am hanging on to the ol' Derale cooler in preparation for the change in climate. You know that in any fluid circulation system the more bends and kinks there are the higher the resistance to flow.
With a little bit of luck I hope to reap some benefit from all these oil mods I've done, or at least not commit any damage.
Trivia question. When installing a spin on filter with an anti drain back valve, and you put the hoses on backwards, how long does it take the stock oil pump to build up enough pressure to explode that rubber drain back valve out through it's own intake holes?
A. About 3sec. Sounds like a firecracker.

 

[retiredgentleman]

The reason I am doing this is partly superstitious, what I mean by that is I have no scientific data to prove a need for more oil flow. I have been wanting to try this out for a very long time and now the opportunity presents itself. I do believe the more oil the better in our case.
A roller element bearing like the ones we use do not require high pressure, that could even be detrimental causing the rollers to skate rather than roll and that creates damage. High volume is another story as it promotes heat transfer away from the bearing, It is more likely to flush out contaminates that our bearings are highly susceptible to, and it increases the rate of filtration, something the spin on filter guys will relate to.
Here in New Jersey a 100mi high speed ride @100*F returned an oil temp of 220*F. No need for an oil cooler, but I do use synthetic oil just in case of getting stuck in traffic or whatever. We plan to move to Florida in a few years so I am hanging on to the ol' Derale cooler in preparation for the change in climate. You know that in any fluid circulation system the more bends and kinks there are the higher the resistance to flow.
With a little bit of luck I hope to reap some benefit from all these oil mods I've done, or at least not commit any damage.
Trivia question. When installing a spin on filter with an anti drain back valve, and you put the hoses on backwards, how long does it take the stock oil pump to build up enough pressure to explode that rubber drain back valve out through it's own intake holes?
A. About 3sec. Sounds like a firecracker.

I think you're fooling yourself, if you think you will get double the oil flow as compared to a stock pump. I agree with Jack, saying that the designed in oil orifices inside the engine, and the orifice in the external pipe going to the camshaft, will only pass what their capacity will allow. You can't force more oil through just by doubling the size of the pump. You would have to enlarge the oil orifices in order to have increased flow.

Mikesxs sells a lot of parts of sub standard quality. The $200 seems like a lot of money for very little if any gain. The stock oil pump is high quality and pumps the design oil flow.

The extra flow may increase the pressure at the side cover oil strainer/filter, and cause the relief valve to open. That means you could have unfiltered oil going into the engine.

Best thing for the engine lubrication...................frequent oil changes, a real paper oil filter, allow the engine to warm up while idling to prevent ripping the sump filter, and if moving to Florida, install a good 100% flow oil cooler.

 

[CDNTX650]

It's a shitty product regardless. My quality mikes pump rotors bound up so bad it went in the trash. I did the external paper filter instead.

 

[650performance]

When Yamaha created the OU race engines in 1976 they used the stock oil pumps. This suggests the engineers believed the stock units would be sufficient for about 90 HP at the crank and 9000 rpm overrev capability. Also, Lillie, Axtell, Branch, Shell, etc. all used stock pumps in the hundreds of race engines they built.
I think it is fair to conclude from this that any street ridden XS engine can probably get by with a stock oil pump that is in decent shape and properly clearanced.

 

[Spockwerks]

It's a shitty product regardless. My quality mikes pump rotors bound up so bad it went in the trash. I did the external paper filter instead.

Oh wow man, I really didn't want to hear that. For 200 bucks, or even for 20 bucks I expect a quality product. If this pump fails on me I will sure make some noise about it.

I did the spin-on filter thing too, quite a while ago and it has been flawless. I do change the hoses every 2 years or so.

 

[Spockwerks]

When Yamaha created the OU race engines in 1976 they used the stock oil pumps. This suggests the engineers believed the stock units would be sufficient for about 90 HP at the crank and 9000 rpm overrev capability. Also, Lillie, Axtell, Branch, Shell, etc. all used stock pumps in the hundreds of race engines they built.
I think it is fair to conclude from this that any street ridden XS engine can probably get by with a stock oil pump that is in decent shape and properly clearanced.

Sounds a little like apples and oranges. Over here we have engines thrashed within inches of their lives that are torn down and renewed after every race with unlimited spares. The primary concern is getting every scrap of horse power to the ground. Longevity is no virtue.
Street bikes are usually required to perform at far more sedate levels but over a time span measured in years or even decades between major maintenance events. I have had this bike for 30 years and this is the third time it has been apart. Unachievable by race bike standards.
Someone once told me about a XS650 that had the oil passage to the valves plugged up for a terribly long time, yet it showed no unusual wear, the top end lubricated by splash from the chain. I have no doubt that any number of racers experimented with ditching the pump altogether. May be an easy 3~4 horsepower gain for a while. Husqvarna built 4 stroke thumpers with no oil pumps at all for years with much success.
I agree, racing improves the breed.
But racing mods are not necessarily where it's at here in custom land.

 

[angus67]

would you rather hear this before you buy it? or after your pump seizes at 100 mph?
Just go with the stocker, and check clearances. odds are, you'll be fine.

 

[angus67]

Sounds a little like apples and oranges. Over here we have engines thrashed within inches of their lives that are torn down and renewed after every race with unlimited spares. The primary concern is getting every scrap of horse power to the ground. Longevity is no virtue.
Street bikes are usually required to perform at far more sedate levels but over a time span measured in years or even decades between major maintenance events. I have had this bike for 30 years and this is the third time it has been apart. Unachievable by race bike standards.
Someone once told me about a XS650 that had the oil passage to the valves plugged up for a terribly long time, yet it showed no unusual wear, the top end lubricated by splash from the chain. I have no doubt that any number of racers experimented with ditching the pump altogether. May be an easy 3~4 horsepower gain for a while. Husqvarna built 4 stroke thumpers with no oil pumps at all for years with much success.
I agree, racing improves the breed.
But racing mods are not necessarily where it's at here in custom land.

huh. then maybe I should install a oil pump on my wifes standard bread horse so I not scared shitless to ride it? Would take out 3-4 hp if I read that rite? lol What kind of balls out racing are you planning to do on this motor?
I agree with the street bike statement. I have a 2003 Suzuki marauder I call my long runner. Its my cruiser, never sees the redline at a embarrassing 5k, mostly because of the over sized front sprocket and undersize rear sprocket.
I cant imagine oil splash getting to the outer lobes of the cam. Centrifical force throws it up, not around, even with splash off the top of the cam cover, I just cant see in my mind enuf oil to get over there.
I think those husq's were 2 strokes?
I just cant believe someone would run without a oil pump in a race bike, or anyother bike. Not only does it lubricates, it cools.
Dragsters and funny cars have oil pumps, and they rebuild them after every race. That there is a high dollar hobbie. If they could pick up 4 hp with out a pump, they would do it. They already run without water pumps, radiators.

 

[pcoumbe]

I run a high output pump I bought from De-Muede in Germany. They call it a "plus 50%" pump.
I bought my bike used and had a top end failure due to lack of oil shortly after, repaired that then had a crankshaft bearing fail.
Rebuilt the engine and had to replace the pump as the ring the rotor runs in was cracked so thought, what the hell. I fitted a paper filter and spin on sump filter at the same time.
I spent a bit of time getting the pump right but believe I was lucky and got a pretty good one.
May not add a lot of value but was piece of mind in my case as I think extra oil can only be a plus in a clean engine.
I change oil and filters every 1500klm, use standard motorcycle 4T 20W50 and it runs quiet, has clean filters every service as I always cut and inspect.
I don't dispute the opinions of all here and don't claim to be an authority on the XS engine but am a mechanic. As guys here are advising, which ever way you go, your pump must turn freely without binding and you should be good to go and yes, I run a tacho with the fatter pump.
Good luck which ever way you go.
Pete.

 

[CDNTX650]

Oh wow man, I really didn't want to hear that. For 200 bucks, or even for 20 bucks I expect a quality product. If this pump fails on me I will sure make some noise about it.

I did the spin-on filter thing too, quite a while ago and it has been flawless. I do change the hoses every 2 years or so.

It's not that it just fails. It binds solid and shatters the pump cover and..bends the shaft and sends all those shitty pieces through the engine. It's just not a needed mod anyways. I never had mine break....when it was binding so bad I couldn't spin it by hand i decided it was a junk product.

 

[Spockwerks]

This has got to be the worlds best XS650 discussion group, It's far and away the best one I have ever been part of. Tons of great info and it's all free.
The pump arrived today. First thing I did was assemble it, and holding the housing in one hand gave the shaft a whirl. Smooth as silk, not what I expected, not at all. Then
I took the feeler gauge and tried to force it between the 4 tips of the inner rotor and the 5 bulges of the outer rotor. Not one had more than 0.0015". There is no binding or rubbing anywhere. It has the appearance of a nicely machined piece of kit. There is at this point no good reason to hesitate so am going to proceed and keep you guys posted if anything strange happens

 

[CDNTX650]

See what it does assembled and go from there I guess.