Hi I've got a rover thoroughbred 16" cylinder mower and would like to fit a reliable new engine to it for every day use. It had the B/S 3.5hp on it. I'd like to fit a Honda 4stroke if I can find a replacement with the same specs. Thanks Dan.
The small Briggs engines conform to a set of standard dimensions for location of base mounting holes, and location of output shaft. This means that most standard small horizontal shaft engines will fit directly as substitutes, except for the length and diameter of output shafts: manufacturers usually offer several options for these dimensions. So, the process is to measure your output shaft diameter where it goes into the clutch (not back where it goes through the crankcase oil seal into the engine), as well as the length of the output shaft measured from a line joining the two engine base mounting bolts on the output shaft side. The slightly awkward way of measuring the shaft length is necessary because the depth of the engine's crankcase cover is not a standardised dimension.
The direct replacement Honda engine is the GX120. It is rated at 4 h.p.
On looking through the Thoroughbred specs, I see that the 16" machine had a Briggs and Stratton Model 80202 engine fitted with a spacer underneath, to raise the engine to the same operational height as the optional engine, which was a Kirby Model H4. This spacer may or may not be required if a Honda GX120 is fitted.
Please do not PM me asking for support. Please post your questions in the appropriate forums, as the replies it may receive may help all members, not just the individual member. Kindest Regards, Darryl
Thanks for the info. I've ordered a b/s 3.5 with 3/4" shaft. When you match up the numbers on the cowling to the briggs web site this seems to be the right motor. while I was waiting for the new motor i reground the valves and this made a big improvement to its performance.
