How to Inspect a Used Vintage Honda Motorcycle Engine

 So last summer we were coming back from Mid-Ohio and had the unfortunate situation of blowing our shop CB550 engine due to a small oil leak. Maybe you have been in this situation before. A lot of us find ourselves here when you ride these older bikes long enough. Our solution was to pick up a used engine at a junk yard here in town so we can keep riding in the meantime. Rather than rebuild a engine that more then likely still has some miles left to go on it, we are going to open up the side covers and accessible parts of this CB550 engine to inspect and clean it before loading it into our bike.

Regardless if you are working on a CB350, CB360, CB450, CL350 Scrambler or any other vintage Honda engine from this era, Performing these critical inspections before installing the engine in the frame will make any repairs significantly easier. Follow along in these videos and print out the downloadable checklist to inspect your engine along side us. 

1. Clean the Engine

• Spray your engine down with degreaser, plug your intake and exhaust ports and pressure wash.

2. Verify the Motor is not Stuck / Frozen

• Remove spark plugs and spray penetrating oil into cylinders. If stuck here are common causes:      -Starter motor/clutch binding                                                                                                                  -Rust in cylinders / rings                                                                                                                           -Bent valves / broken cam chain                                                                                                               Take your time investigating, don’t force it. If it does not free up, rebuild the top end.

3. Drain Oil & Replace / Clean Oil Filter

• Drain old oil and either:                                                                                                                             -Replace oil filter (CB500K /CB550 / CB750)                                                                                        -Clean oil rotor (CB/CL/SL/CJ 175, 200,350, 360, 450, 500T) 

4. Inspect the Camshaft and Rocker Arms

• Remove cam covers to inspect camshaft. Bearing journals and lobes need to be free of pitting, galling, and  overheating / discoloration. The Rocker arms should have clean follower pads and tips. Throughly lubricate using assembly lube and oiled before reassembling. Tighten cover bolts w/correct pattern see  Honda Service Manual.

5. Remove Right Side Engine Cover

• Open the clutch and check your friction discs for wear, replace if needed. Clean dirt, sludge and residue from all visual parts. Grease new gasket for easy removal at next service.

6. Remove, Clean and Inspect the Oil Pan

• CB550, CB500f or CB750 only. Check your primary chain for wear. If your engines high mileage and its loose you need to do a full rebuild. Replace pan gasket.

7. Remove, Clean and Inspect the Oil Pump & Pick up Screen

• Use assembly lube and fill your oil pump with oil. This will prime the system. Use caution not to damage filter screen, best to leave attached to pump during cleaning

8. Remove, Clean and Inspect Underneath the Stator Cover

• Remove cover and inspect for any damage. Clean any dirt, sludge and debris out. Grease and replace gasket.

Final tips: Replace your JIS screws on your engine with Allen Head Bolts and cover threads with anti-seize. You will smile upon this decision next time you have to remove these bolts and covers.

↓ Click the link to download the printable version for use during your actual Engine Inspection.