Description
Honda CB500F
1975 Honda CB500F
Superb cosmetic condition
Recent fengine rebuild - details below :
Repairs to Honda CB500K2 Reg. KAW421P
Engine analysis & repairs carried out to cure smoking engine as follows :-
Analysis
Compression test
1st cylinder – 115 PSI, leak down 22%
2nd cylinder – 135 PSI, leak down 10%
3rd cylinder – 140 PSI, leak down 8%
4th cylinder – 140 PSI, leak down 10%
Note:
Normal reading 135-160 PSI, leak down 25% maximum allowable.
Piston/ bore clearances 1st piston/ bore - . 12mm 2nd piston/ bore - . 12mm 3rd piston/ bore - . 07mm 4th piston/ bore - . 13mm Note:
Max allowed . 25mm
New piston ring end gaps as fitted
st 1
nd 2
rd 3
nd – top . 35mm 2
nd - top . 53mm 2
nd – top . 35mm 2
. 46mm . 41mm . 46mm
th 4
nd – top. 33mm 2
. 33mm . 6mm maximum allowable.
Suspected cause of excessive engine smoke was worn oil control rings. All rings replaced.
Scope of work completed:
Engine disassembled to top of crankcase.
Cylinders re honed.
New rings installed on pistons.
All valves removed, cleaned, re lapped. New valve seals installed
Note:
Head reassembled, installed, all valve clearances rest , 002” intake, 003” exhaust. New gasket set used.
Replaced rocker box assembly due to broken edge.
Oil & filter changed.
Carbs checked & bench set. New spark plugs installed.
New battery supplied by MIS and fitted by self.
New parts supplied by self : Spark plugs.
Piston rings.
1 gallon premium petrol Gasket set
M8 x 1. 25 flanged nuts
Piston retainer clips
Rocker box assembly (2nd hand)
Oil & filter
Shop materials. Gasket cement, solvent, paper towels.
Motorcycle now in superb mechanical and cosmetic condition
Beautiful example of a quite rare motorcycle the CB500 four is widely regarded as one of the very best versions of Honda first generation four cylinder motorcycles.
Model history
It was introduced at the London Racing and Sporting Motorcycle Show in February 1972, and sold in the US market until 1973, replaced by the CB 550 in the 1974 model year, while continuing in the European market until 1978. The CB 500 Four is styled like the CB 750, but smaller and lighter, with a claimed of 50hp output and a top speed of 185 kmh. Like the earlier CB 750 it has a single front hydraulic disc brake, rear drum brake, electric starter, and sohc eight-valve engine. The four-into-four exhaust pipes echoed those of the CB 750. Unlike the earlier dry sump CB 750, the smaller bike has a wet sump engine. Also, the primary drives were different, the CB 750 having a duplex chain, while the CB 500 had a "Hy-Vo" Morse chain.
