1977 Liquifire KEC 440/23LC Crank Bearing Info

[tweiss612]

Does anyone have information on the part number or cross reference number of the outer crank bearings for this engine? Looking at doing a top end rebuild on mine and thinking if I have it apart I should replace the bearings as well.

Also, mine only revs to about 5800 rpm. I gutted the pipe on it to get a little more sound out of it, didn't really pay attention to if it started right after I modified the pipe or not. Did a little racing this weekend and noticed its not revving up as much as it should. Wondering if anyone has had a similar experience. Runs and drives perfectly fine, takes off out of the hole quick, just lacking top end.
I also have a stiffer primary spring in but don't think that should affect final RPM. Everything in the clutches is in fairly good condition.

[Green and Gold]

PTO bearings. JD AM53977. Jobber number 6206. 62 x 30mm
Mag bearing. JD AM53392. Jobber number 6305, 62x25mm

The Mag bearing on the NOS late numbered cyclone cranks I have are marked 6305 C3 , which designates a with more bearing to race clearance. Don’t have a liquefier to check, sorry, but the bearing share the same JD P/N. The PTO bearings are not marked C3.

As far as the low revs go, my checklist would include obstructions in intake or exhaust, belt width wear, clutch wear, drive train obstructions/binding.

Good luck

[400brian]

If it needs bearings, I would suggest it needs center seals as well. Send it to Jerome and have all the bearings, and center seals replaced.

Just a thought, they do not run well if the center seals are leaking. Firsthand experience on that.