Oil pump mod (650)

Anyone seen or heard of this? Had my pan off 10-12 years ago for stripped drain plug so went ahead and did it. Apparently been working fine all these years. Forgot I did it until looking thru my Clymers book in improvement section. Some extra pressure is a good thing!



Post edited by: Bluemeanie, at: 2008/01/17 12:51

I do the same thing on the race car engines I build, works well

Does the 1000 use the same method? This is a great trick and in the manual hhhmmm.

I'm not familer with 1000's but would think so. My clymers manual has a chapter 12, performance improvement. They recommened (old school)Gerex, Andrews coils, RC electronic ign. RC header and big bore kit (717cc). S&W shocks, springs, 29mm smooth bores, etc. Pretty cool stuff. Check your or a friend Clymer for it.

galaxian wrote:

Does the 1000 use the same method? This is a great trick and in the manual hhhmmm.

the 900-1000 motors are a differant beast,very little presssure needed.you sand/mill a little off the housing to tighten up the clearance between gears and housing.the 650 style motors on the other hand use bearing inserts like a car and require more oil pressure.be carefull shimming the spring on oil pump because too much oil pressure is not good either.on v8 motors a good rule has always been 10psi for each 1000 rpms,ive seen the results of people trying to run 120 psi of oil pressure it aint a purdy sight!:blink: :ohmy: :sick: :S :dry: :huh: :blush: :whistle:

Plummen is right 10 lbs per 1000 rpm , car engine, I think the 1000 only runs like 5 to 8 lbs, but they have a roller bearing set up and dont require the pressure, the 650 uses a std type bearing

My 1000 runs about 6psi when riding. Little more when reved up, little less at ldle. I would love to bump it up a bit just for peace of mind, maybe 9-10psi. I don't think it would hurt anything would it?

The point of the pressure is to get the oil to move uphill from the sump all the way up to the cams. The oil journals are pretty direct in the openings around the studs. I think there might be a problem in a very high performance bike which sloshes oil to the rear of the pan so a combination of an oil gate in the pan AND a bit higher pressure would be helpful... the extra pressure would ensure a bit more oil to the cams. Most boy-racers use external lines for this reason I think. I don't ride all that hard but I use a gate in almost all my bikes because it is REAL EASY for the pump to have no oil to push if the oil is sloshed to the rear of the pan. I think the big problem with too much pressure would be more chance of leaks around the cam plugs, tach drive seal and valve cover gasket which tend to dribble anyway. I would guess a bit higher pressure would not have any symptoms if you sealed all three of these things good. Higher pressure would also find out any bad engine seals like around the shift shaft or crank end or kicker shaft, etc but unless these are damaged, I can't imagine 3 or 4 lbs of pressure making them seep. Don't the turbo bikes run more pressure? If so, you could ask Saunders or someone about where you might have issues.

Yea, I did this oil mod long time ago but everything works great with over 53,000mi on motor. I did it with the confidence that it would not be overkill such as too much harmful pressure. I think whoever experimented with this found a helpful increase in pressure for the benefit of the motor. I had the usual tach drive leak and end cam plugs (hard as a rock) but crankshaft and other seals are dry as a bone. My engine is stock but I do enjoy winding it up quite a bit and I think the slight increase in pressure has helped the motor. They say it also helps in the cooling process too.

turbo bikes do need a little more pressure to oil bearings on turboB)