Hitchcocks Forum

Hi guys----------- I hope you can see that there are 2 different types of exhaust valve seats fitted to these two heads...One is quite deeply recessed and I believe this to be from a home market bike. ..Is the other an English one, from our hosts maybe ??( It's known to have come off an English Bullet ('cos it's off my No.2 bike--which IS English spec)..... Any elp much appreciated.

Well--------------- it would help if I were to download those photos, eh ?? ------------------------------------------------------------- -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

That is quite deep. I suspect the seat has been regressing into the head.

Alan - I had a very helpful gentleman assist me with getting new seats fitted to mine when it was needed - if you want I can forward his details to you? I bought the parts from our hosts and sent them to him along with my cylinder head and he arranged for the whole thing to be done, very reasonable price.

Alan, get new ex oversize seat and valve fitted, maybe a good idea to replace both valve guides at same time as you will require new valves due to the oversize seats anyway,

It was me who had it done for Peter at my local head shop, who due to the large ex seat had to source the seats from the USA, then maching seats to to fit the new much larger valves, if you are interested the shop is based in Warrington Cheshire (Headshop UK Ltd) you can call em on 01925 861166. if you have starting prob or lack of umph but the valve adjustment seems ok then you need to replace existing top end with the larger stuff, HM valves will do but you might have prob getting someone to locate matching seats then match it all up, As the Headshop UK done mine and Peters you know that it can be done. At the end of the day a head is a head. (Peter 53 hows the head now i had it done for you?)

Hello Paul! Long time no hear... yes thanks the head is great now and it's been a year now (?) that I have enjoyed riding my Bullet. Have been playing with various silencers, some good, some not so good, have changed the whole front end for one with a disc brake, and all is good. How's the yoga going?

Hi guys--------- and thanks very much indeed for all that useful info...Even better as the results are actually in service and out on the road... I'm fortunate in that I also have a dedicated Cylinder Head Shop close by and quite a few of the local bikers have used it over may years---myself included..BUT,--I'm more interested in those American seats and the big valve that you mentioned... At the beginning of this year I fitted one of our hosts BIG exhaust valves to prevent it being pulled through due to extremely close sizes at the periphery... After approx. 3,250 miles it failed with a lot of small "Pock" marks on the valve's seat...I returned it to our hosts who have forwarded it on to the manufacturer for their comments..... Is YOUR big valve one of these or from the USA ???...So which combination is now running in the cyl. heads of yours and PETER 53's bikes ??--- and can I get it/them here ?? ---- Yes you can't see it but the old guides are already removed in anticipation of new...Bronze, of course !!

To be honest Alan I can't remember now which parts came from our hosts and which were sourced by the Head Shop in Warrington as it was about a year ago, and my poor brain struggles with what happened yesterday... Paul who sorted it is the one to ask as he lives very near these people.

Alan R:- it all started when i had my 65 head done (couldn't get it to run,turned out the ex valve had retarded into the seat)the only way around it was to have HM's larger valve fitted, (also had the inlet done at same time)after taking it to the local head shop, they then had to locate a new hardened ex valve seat (HM don't supply these) to match the exhaust port & new larger valve, the only one which would fit was from a supplier which they use over in the USA that's how big the hole was (i think the real prob was the inner diameter, to be able to make a good seat around the valve head after it had been machined to match the angle of the valve head, the head shop fitted the new valve seat which then has to be taken down to match the valve head, with the right amount of stem showing out of the valve guide (am not sure what that measurment was off hand but HM can help there)Peter had the same work carried out, he sent me valves & springs the head shop has there own bronze guides (they use them in Porche cars, so is ok for the enfield)they rebuilt the whole lot together again so you only then need to refit (with new valve caps)Peter does your bike sound different now?? if not sure Alan, you can allways give me a bellon me land line, send me an email and will attach a number (if you can't make out what am saying) First thing though is to get your new valves/springs n stuff then take em over to your head place see what they say m8.

Hi guys------OK then GURU, if you put up your E-mail address (remember to do it phonetically so's the SPAM machines can't read it)and we can chat in detail....I thought that HM did do a hardened exhaust valve seat ??