oil pump gear mod

[Anonymous]

Hello all. I had my engine totally apart right after I first bought the bike about a year ago. I discovered that the original oil pump gears had been changed to ones that spun the oil pump faster, at a given rpm. Since I didn`t trust the fellow who owned the bike before me (he didn`t have a clue on maintenance) I went and replaced em with the stock gears. Sooo-my question is has anyone heard of this mod before, is it a Rube Goldberg idea or does it actually help things out in the lubrication department?
Thanks in advance.

[Anonymous]

Pumpin oil.....

45:
First off.....what do you have....which GS model, displacement?
My impressions of the GS line is that they all have just fine oiling systems...mind you MOST GS's have a low pressure oil-pump, far less pressure than most. (It has to do with the crankshaft bearings being of the roller type). It just doesn't make sense why anyone would want to modify this pump.
Rick.......

[Dink]

Let us assume that you have an 1100 or 1000 cc Suzuki . the oil pump gears that were fitted were probably from a 750 that does in fact help, it slightly raises oil pressure and increases oil volume around the motor and is a common mod done to these engines. If the previous owner was a bit suspect it is likely that this mod was done by a different previouys owner.
Dink

[Hap Call]

I have done this mod myself. If you have a 16-valve motor that is 1000cc or 1100cc you can install oil pump gears from a 16 valve 750 motor to increase oil flow. The pressure increase is almost non-existent. All the 16 valve motors share the same oil pump. Because the 750 motor requires a high pressure oil system to lubricate its' plain bearings, the oil pump is spun at a higher rate (thus the different gear ratio) than the 1000cc and 1100cc motors, which have ball bearings on the bottom end. Due to different gearing on the primary gears and secondary gears the overall increase in rpm of the oil pump with the 750 gears is only about 12% as I recall.

The idea is to increase flow to the top end where your cams ride directly in the head. This becomes critical if you start to install higher lift and duration cams. Another option is to install a top end lube kit, which allows an increase in oil flow to the cams. You have to install this kit when you are using aftermarket cylinder studs. Normally the oil flows to the top end via the space around the studs. If the new studs are larger in diameter, this will restrict your flow to the top end.


Hap

[Paul]

You can also use the 750 oil pump gears on a 2-valve GS1000. It pumps the oil round faster, & so the pressure increases slightly. It is mainly for increased oil flow to the top end - more important in a motor with high-lift cams etc - but still a very good mod for a standard bike.
Star Racing, Vance & Hines etc used to sell a kit which was a pair of gears which just happened to be the same as GSX750 gears!! Only they were a lot more money than a set of gears off a wrecked 750!

[Anonymous]

You can also use the 750 oil pump gears on a 2-valve GS1000. It pumps the oil round faster, & so the pressure increases slightly. It is mainly for increased oil flow to the top end - more important in a motor with high-lift cams etc - but still a very good mod for a standard bike.
Star Racing, Vance & Hines etc used to sell a kit which was a pair of gears which just happened to be the same as GSX750 gears!! Only they were a lot more money than a set of gears off a wrecked 750!

I think I paid $40 from murdoch racing for rmy 750 oil pump mod.

[Jeff Tate]

I got a set from Vance and Hines years ago. No problems. '82 GS1100EZ

[Hap Call]

Mine came out of a wrecked '81 GS750...$20. These are getting harder to find!

Hap

[Anonymous]

oil pump gear mod

Wow, lots of great replies!. Sorry I didn`t elaborate on the bike.
Yes it`s an 1982 1100E, and the gears I were questioning are from the 750, thanks to the local dealer checking out the number of teeth on the gears for me. I appreciate you guys enlightening me. I`m going to have the clutch off of the thing soon, and I`ll be able to change the gears easy enough. If it makes the beast last longer, I`ll do it. That was my main concern. The reason I got the bike cheap and had to take the engine apart was due to the oil pump seizing, the gear coming off the pump shaft and chewing up the gear and the clutch basket and then the engine running dry long enough to waste the cams and the head. Definitely an expensive experience. But worth it because the engine is fresh now and these bikes have a high fun factor built into them.

[Anonymous]

Re: oil pump gear mod

Wow, lots of great replies!. Sorry I didn`t elaborate on the bike.
Yes it`s an 1982 1100E, and the gears I were questioning are from the 750, thanks to the local dealer checking out the number of teeth on the gears for me. I appreciate you guys enlightening me. I`m going to have the clutch off of the thing soon, and I`ll be able to change the gears easy enough. If it makes the beast last longer, I`ll do it. That was my main concern. The reason I got the bike cheap and had to take the engine apart was due to the oil pump seizing, the gear coming off the pump shaft and chewing up the gear and the clutch basket and then the engine running dry long enough to waste the cams and the head. Definitely an expensive experience. But worth it because the engine is fresh now and these bikes have a high fun factor built into them.

You are just tasting the icing on the cake with that 1100cc thing.

[Anonymous]

Mods...mods.....

I have done this mod myself. If you have a 16-valve motor that is 1000cc or 1100cc you can install oil pump gears from a 16 valve 750 motor to increase oil flow. The pressure increase is almost non-existent. All the 16 valve motors share the same oil pump. Because the 750 motor requires a high pressure oil system to lubricate its' plain bearings, the oil pump is spun at a higher rate (thus the different gear ratio) than the 1000cc and 1100cc motors, which have ball bearings on the bottom end. Due to different gearing on the primary gears and secondary gears the overall increase in rpm of the oil pump with the 750 gears is only about 12% as I recall.

The idea is to increase flow to the top end where your cams ride directly in the head. This becomes critical if you start to install higher lift and duration cams. Another option is to install a top end lube kit, which allows an increase in oil flow to the cams. You have to install this kit when you are using aftermarket cylinder studs. Normally the oil flows to the top end via the space around the studs. If the new studs are larger in diameter, this will restrict your flow to the top end.
Gadzooks!!.........learn something new everyday!!
Rick......


Hap