Thread: oil pump question

Ive been replacing the stock oil pumps when I have a motor apart with the aftermarket pump that Dr ATV sells.Its supposed to have 250% more oil pressure and I thought it would be a improvement.Does anyone else use these or is the stockpump adequite lubrication.They're cheap enough ,24$just for saftys sake I always thought it would be an improvement.Does anyone else use these and have you ever seen the stock pump fail,Thanks in advance,Greg

I would think it's a good ideal the price is right. You would definitely want to if you do any mods to the motor.

The extra oil also helps cool the engine. Helps with big bore kits and more compresion.

Honda has a pretty good reputation for engineering things to last, so for "normal" use the stock pump should be fine. (But whose definition of normal should we use??) That being said, more pressure and volume, within reason, shouldn't cause any problems, and it's kind of like having an extra margin of insurance, right? And when we start boosting the performance, and adding oil coolers, and running for extended periods near peak revs, more insurance in the lubrication department makes sense. At least it makes sense to me.

-kevin

one oil pump came with a drill bit to enlarge the opening,another didnt.anyone remember the size of the bit for the new oil opening

Two key points: these engines started out as 49cc lumps; the original style oil pump is long-discontinued.

Taking a 49cc engine putting out 3hp and increasing displacement to 72cc and output to 4-5hp puts a lot more stress on the lower end & cooling system. Ultimately, Honda took the design out as far as 90cc and made it work reliably, in later years. Now consider that the "cooling system" is the finned area of the upper end. The only way to increase cooling capacity is via the oil. The larger, late-model oil pump is a clean & simple solution. These motors need flow volume, not pressure. Excessive oil pressure at the pump would place extra stress on the oil pump drive (cam chain & drive sprocket) hence the need for a larger metering orifice. Added oil flow through the head should keep things cooler and, should one decide to add an external oil cooler it will be more effective with the larger pump. It's not like there's much of a choice; the way this works out, that's not a bad thing.