If you like this website or have found what you were looking for, then please support us by donating a small amount!
Thank you very much!

Smart Search

Advanced Search

Login here

By logging in, you also log into the forum, the download sec- tion and the photo album.

Follow us!

twitter youtube
rss-feed   atom-feed
RSS Feed   ATOM Feed


Hi and welcome! This website is entirely dedicated to the Honda fourstroke moped and motorcycle family.
Whether you have for example a Honda C50, CB50, SS50, PC50 or CB350, this is where you need to be!

Use the search field on the left, or use the menu to navigate yourself through a maze of data!

If you want to add data to our archive project, please upload it to us!
To upload, you need to be registered and logged in. You can register for free.


User Rating:  / 2

This tutorial describes the general way of adjusting the valve tappet clearance of a Honda engine. The mentioned clearances are applicable to Honda C50, SS50, PF50, PS50 and PC50. But just to be sure, double check the clerances for your model.

Alright, first of all, you need a so-called feeler gauge, which you can see here: http://en.wikipedia.org/wiki/Feeler_gauge
They can be found sometimes cheap in the dollar bin at the gas station.

Settings to remember:

Intake valve tappet clearance : 0.05mm (0.002in)
Outlet valve tappet clearance : 0.08mm (0.003in) (note that this is not the factory setting, but a setting "from experience"

The picture of the cylinder head you see is from a PC50, but that is the book I have at hand now. PF and PC do not differ in the way of adjusting the tappet clearance.

Here we go:
The tappet clearance will have a great deal of effect on the valve timing. Further, if the clearance is too small, it may prevent the valve from fully closing and result in pressure leak at the valve or even a burnt valve seat. On the other hand, an excessive tappet clearance will produce tappet noise, causing noisy engine operation. The tappet clearance will also have a varying degree of effect on the engine power output and engine operation.

1. Remove the dynamo cover and align the timing mark "T" on the flywheel with the timing index mark on the crank case. To be absolutely sure that your piston is at the top-dead-center, remove the spark plug and carefully feel the position of the piston with a small screwdriver. If you do not want to do this, then you can check it by feeling both rocker arms. They should be loose at the "T" mark. The screwdriver way is better, because it also gives you the opportunity to clean and check the spark plug.

fig 1-8

Fig 1.8

2. Remove the tappet adjusting cap on the cylinder head and check the clearance between the adjusting screw and the valve. If the valve is actuated by the screw, rotate the flywheel one complete revolution and realign the timing marks to set the piston at top-dead-center (TDC) of the compression stroke. Check the tappet clearance with the gauge to see if it is of standard clearance as described in the list above. If adjustment is necessary, loosen the adjusting screw. Lock the adjusting screw after adjustment has been completed.

fig 1-9

Fig 1.9

How to FEEL the thickness: It's always a debate what is the best way to determine the correct clearance, but my way of feeling is if you have to wedge the gauge in and the gauge is really difficult to move back and forth, then the clearance is too tight. If the gauge easily slips through, the clearance is too loose. When you move the gauge back and forth and it's moving "sticky", then you are on the right way and the setting is probably right.

Of course, there is no such thing as a 0.08mm valve gauge, that would make tings too easy. So, of you have set the exhaust tappet clearance to 0.05, loosen up the screw a very tiny little bit. That should cover it.

1. The adjustment must be made with a cold engine.
2. Hold on to the screw while tightening the cock nut. Sometimes the screw is dragged along a bit while locking.

We're sorry, but it appears that you have no permission to posts a comment. Perhaps you forgot to log in?

Free Kilometers

Current amount of free kilometers earned due to people littering:

Earned so far: 61,05 Km

Thank you, but please be a civilized human being and clean up after yourself...

English Dutch French German Portuguese Spanish

Quick Guide

Simply register and you have free access to:
Our user-friendly forum is multi-lingual!
We are open and helpful to any question and we offer you help in Dutch and English.
Specifications per model/type
We are gathering as much data as possible about every single
model that Honda produced, from sizes to colours to spark plugs.
Workshop manuals
If you are looking for a Honda Workshop Manual, go have a look in our extensive library.
Setup manuals
We managed to get our hands on some Honda setup manuals for the C50
Parts lists
Honda Part Lists are crucial for any restoration work
Owners Manuals
Every new bike that left the dealer got delivered with a Honda Owners Manual. Always handy for quick maintenance tips!
Exploded views
Forgot how things needed to be put back together? These help a lot!
Wiring diagrams
Turn spaghetti wires back to order with these Honda Wiring Diagrams

Fuel Consumption

Honda PC50 - 1965
59-DBP-8 / VID: 641393


Honda SS50 - 1976
**-***-* /  VID: 641399
(out of order)


Honda PS50
(not set up yet, engine repair)

Honda PS50
(not set up yet, total overhaul)

Honda P50
(not set up yet, total overhaul)

Honda P50
(not set up yet, various repairs)

Honda PC50
(not set up yet, various repairs)



Legal Stuff

            Copyrights and Sources - Privacy Policy - DMCA Claims
                                  Proud member of the 3XN Network

Safety First

Meet our blood hounds...
@ Member of Project Honey Pot [Link]
SHPN provided by Unspam [Link]
SBC by VI-Solutions [Link]
Domain Ban List by 3XN.nl
syringe-icon SQL Injection protection by 3XN.nl
lightning-64x64 copy Software Monitoring by 3XN.nl

Free SSL Secured By StartCom