Hi guys

How i can remove carbon deposits from piston and cylinder head . Appologize this is c15 . :(

Regards
JH

Strip everything down to the base castings...(piston and head) and find someone with a vapour blaster...

Bead blasting or vapour blasting is the only way to get them completely clean..Ian

email (option): ian@wright52.plus.com

If it is the C15 head and piston you are cleaning use a scraper that is not harder than the material that the cylinder head / piston is made of - Both alloy in the case of the C15 so a piece of wood or plastic will be fine. The valve inserts are hardened steel so a roatary wire brush on an electric drill will be O.K. I use a well worn piece of emery paper for the valves whemselves - and for speed these can be fitted to a fixed drill to spin them faster. Obviously then it is just a case of grinding in the valves etc and reassembly - This, of course, is the low-tech slow-tech process. Ian's will be much faster but I fear I am only a mere mortal and do not have access to such gadgets as vapour blasters, etc.

email (option): cliveandjo@lineone.net

Leave the valves in the head and use a brass wire brush in a drill or something - make sure you get a brass wire brush as some steel ones are brass colored.

Then remove valve and clean backside again with a wire brush - steel or brass.

AS for the piston top - i have found that brake cleaner liquid and sometime cellulose thinners will start to dissolve/soften the carbon - then try sometime gentle like an abrasive pan scrubber.

For gods sake don't try 'Sivit Bang', drain ceaners or some oven cleaners - highly alkily and can eat your piston.

I understand some dish washer detergents can shift carbon, though never tried.

Bead blasting and aqua blasting is a lovely way to clean inside and outside of heads - you may be surprised to find someone local ?

['clean backside again with a wire brush']...

Once is too much I would say.. ...Ian

email (option): ian@wright52.plus.com

Thanks lan/nigp/andrew for advise . Points noted
There is a blasting company in town i will check out.

One last question . I have another cylinder head in better condition but have broken valve guide .
How to remove valve guide from other cylinder head . ?
I am thinkjng take out valve/guide puting in better one.?

Sorry im newbie with british bikes ..

Valve guides are usually drifted out using a hammer and a punch made for the job..

Warm the head to approx. 100 degrees before removing the guide and before fitting a replacement...
There isn't much point in fitting a 'better' guide...Fit a new one..

After fitting the guide bore will need to be reamed/honed to size to match the valve (which shouldn't have too much wear on the stem and should have a good valve seat face...)

Finally the valve seat will have to be recut after the guide is fitted to ensure it is totally true to the axis of the new guide...

This work is best carried out by an engine refurbishment shop if you are unfamiliar with the work/don't have the equipment...Look for somewhere that does rebores and they will probably be able to do the work...

It's not expensive work, however, you will need to supply a guide and the stem clearance figure for the engineers and take the valve along so they can check it for condition, measure it for clearance and to regrind the valve face...

If you are unsure of when they were last replaced I would fit new valve springs as well...

If needed you can get guides/valves/springs and other C15 parts from C&D Autos....You'll find them without difficulty if you google it...

If you don't have it already, get the factory manual/worksheets for your C15 model for all the clearance information etc. etc.....Ian

email (option): ian@wright52.plus.com

Don't have the head sand/grit blasted - aquablast is best (water is the carrying medium) followed by glass-bead. If in doubt have a feel at a sample - wants to me nice and smooth/silky - go with grubby fingers and see if the sample marks up and cannot be cleaned (TEE HEE).

If the guides broken, it will have been cast iron (grey material)- this is the best material !
Sadly replacements will be various grades of brass/bronze - often, complete crap!
PSS/CCM sell wonderful quality guides - at a price!

Chucking the head in the oven while the wife's out, will heat it enough to help knock the guide out - what explanation you give for the smell/smoke is up to you!

Fitting a new guide - check thst you cannot press the new guide into place @ room temperature, if you can, its no good (all too common) - oversize guides are available!

If the guide is good - throw it into the deep-freeze for a day or so, then when wifey is out again - heat the head up, until when you spit on it, the spit bounces off.
The cold guide should now, lightly knock into place - make sure it bottoms on its flange.
Let it all cool, then find someone to cut the seat - you can have a try and see if the valve will form a seal, but don't go mad with the electric drill and grinding paste - it rarely works out.

RE valve springs - again we are plagued with poor pattern parts - measure the old spring length and if anywhere near the correct length - re-use them!

Certainly, if there is anyone local who can do a head for you, get a price, but its not hard to do yourself.
One of the enjoyable things about this hobby is that often some old fart at the head/blasting company will reconize the head as a C15, then you have to listen to all his stories about them - before he does the job for you for a £5 !!!!

This happened to me a couple of days ago - at a local machine shop (HeadMasters - Bently, South Yorkshire), i mentioned our Bonneville plans - turns out he did the 2015 M/C CannonBall run on a 1926 Rudge (diagonally across USA)and is doing the 2016 run on a pre1917 Triumph H ....!
We could be buddying up on the shipping costs !!!!!

Thanks lan/nigp for your advise i am noting down these brillant techniques
the main issue she is not going out when i want .. i think i need to buy her cinema tickets or something ..

Regards
JH

I seem to remember the HOBBIT films are overly long ..... should give you enough time.

Failing that a camping gaz stove, or in my case two plumbers blow torch will do.

I think i stated PSS - that should have been PES/CCM they make some truley nice valve guides in varous oversize.

For you M20/21's out here, he also has various bits of engine for these as well - valves, pistons etc.
Don't bother trying to phone him as he has his wife now working the CNC machines instead of manning the phone - use email which he checks once a week .......... not very business minded is our Mr Cook!!