New-style connecting rod for Onan 18 to 20 horsepower twin-cylinder engines, replacing Onan part number 114-0397. 114-0397 superseded the earlier 114-0257. Onan built these rods two ways. The new style is a solid I-beam and carries casting number 170-4447 A, B or C. The old style has a hole cast through the lower end of the I-beam and carries casting 170-4105 A, B or C. They weigh differently, so the casting number on the rod is what identifies the part, not the engine serial number and not the model badge. If the rod you are replacing has the same casting number as this one, replacing a single rod is fine. If you are moving an engine from old style to new style, replace both rods so the reciprocating weight stays matched. Fits P218G, P218V, P220G, P220V, B48G, B48M, P248V, BGA, BGAL, BGD, BGDL, BGE, BGEL, BGM, OL18, OL20, OLV20, LX770, LXV770, LX790 and LXV790. The near miss to watch for is the 16 horsepower rod, part number 114-0394, casting 170-4444 new style or 170-2429 and 170-3439 old style. One digit separates 170-4444 from 170-4447. Rod bolts are included. Rod bolt torque is 12 to 14 ft-lb. Sold as one connecting rod in standard size. Bearing inserts, the second rod and the piston are not included. Gravity cast,
- NEW STYLE SOLID I-BEAM ROD - CHECK YOUR CASTING NUMBER FIRST - This is the new-style Onan connecting rod. The casting number 170-4447 A, B or C is cast into the rod itself. The old style has a hole cast through the I-beam near the big end and carries casting 170-4105 A, B or C. The two do not weigh the same. Read the number off the rod you are pulling out, not off the engine tag.
- FITS 18 TO 20 HORSEPOWER ONAN TWINS - P218G, P218V, P220G, P220V, B48G, B48M, P248V, BGA, BGAL, BGD, BGDL, BGE, BGEL, BGM, OL18, OL20, OLV20, LX770, LXV770, LX790 and LXV790. Replaces Onan part number 114-0397, which superseded 114-0257.
- DO NOT MIX OLD AND NEW STYLE IN ONE ENGINE - If the rod you are replacing carries the same casting number as this one, you can change just the one. If you are going from old style to new style, change both rods so the engine stays in balance. That is the rule that matters here.
- THE 16 HORSEPOWER ROD IS A DIFFERENT PART - The 16 HP rod is 114-0394, casting 170-4444 new style, or 170-2429 and 170-3439 old style. 170-4444 and 170-4447 are one digit apart and that digit is the difference between a 16 HP engine and an 18 to 20 HP engine. Confirm the casting before you order.
- CHECK THE CRANK JOURNAL WHILE THE PAN IS OFF - A new rod will not save a journal that is scored or out of round, and this is the only moment you will get a proper look at it. Mic it against the service limit before you close the engine up. Rod bolts are included, torqued to 12 to 14 ft-lb. Sold as one connecting rod in standard size. The second rod and the piston are not included.