What are the torque specs for a 1990 harley Davidson fxrp head bolts?

Answer 1

It's not so much a single number as a sequence. The head bolts must be tightened in steps and in a particular order.

First make sure there's a light coating of motor oil on the bolt threads and on the undersides of the bolt heads to ensure accurate torque figures.

The tightening order is:

Front Cylinder:

1) Front left bolt

2) Rear left bolt

3) Front right bolt

4) Rear right bolt

Rear Cylinder:

1) Rear left bolt

2) Front left bolt

3) Rear right bolt

4) Front right bolt

Torquing procedure for both heads:

A) Tighten bolt #1 to 7 ft-lbs.

B) Tighten bolts #2 through #4 to 7-9 ft-lbs.

C) Tighten bolts #1 through #4 to 12-14 ft-lbs.

D) Tighten bolts #1 through #4 EXACTLY 1/4 turn (90 degrees). Use a felt marker to ensure accuracy.

Do not attempt to further tighten them at any point in the future. Always allow the motor to reach full operating temperature before riding at high RPM to prevent blown head/base gaskets.

Note: Certain aftermarket head gaskets (like Cometic EST multi-layered metal gaskets) require a different torquing procedure but the above applies to all brands of non-metal gaskets, including OEM.