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[slowmo]

my 03 500 iron barrel at 10K has suffered the ubiqitous burned valve and badly pocketed seat (1.5 mm recessed). Dont think I am wholly guilty of the crime as problems became obvious after only 500 miles of me taking on the bike (that could just be denial though!)Took to local workshop for replacement guides and valve seats etc, but after 2 weeks they informed me that although they had passed the head around various contacts, none had the equipment to remove/replace the valve seat withou risking damage to the head.


Quick questions then; 1 can anybody recommend a M/C workshop capable of carrying out this work (the closer to Bristol the better) 2; I bought the hitchcock supplied valve seat and OS valve, but as this is turning out to be expensive job, are there any alternative ultra hard seats available that could be used instead for a future proof repair? 3: is a replaced seat going to be secure or is it more prone to dropping out in future?


Ta for any advice

[Barnes]

Hi. Give t&l engineering a ring. They are nr bedford but they do any and all engine work. Inc valve seats if memory serves me right its about 65 quid per seat. They will also cut and grind it for you. Tel:01234 352418 ask for dereck. Cheers ed

[Paul M H]

You could try Hitchcocks. As there workshops is now open as listed below. Although not well advertised on the site yet here is the details below.

After a long period of planning and preparation we are pleased to announce that our new SERVICE DEPARTMENT workshop is now operational.

This purpose-built, spacious, modern and fully equipped facility will allow us to carry out
servicing, repairs, modifications and expert fitting of our performance parts to customers’ Royal Enfields. The workshop is also equipped to analyse and tune customers’ engines using our new dynometer installation.

Bookings for workshop time may be made using our usual phone number: 01564 783192.

[Alan R]

Head Techniques, Telford do all mine ( and other R/E owners ) R/E Heads including seat replacement, grinding etc.}-------- http://head-technique.co.uk/

[Tim NZ]

The shop you went to is useless! find another.


Getting the old seat out is easy: weld a section of solid steel bar onto the valve seat, heat head to HOT, then with a drift down through the valve guide tap out the old dead seat. Occasionally simply welding the bar onto the old seat causes enough contraction of the seat for it to simply drop out.


Cceck dims of old recess against the Advised OD of the new seat, allow for 0.003" - 0.005" interference fit. Usually a std valve seat 'blank' is preferred over the factory replacement part, so that the recess can be cleaned up and new insert made to fit.


Approx 2 hours work required if the shop knows what they are doing...

[The rider formaly known as Lone Rider]

I had a similar problem. It was the EX valve.

The valve was undersise, and continually kept pulling through the seat area.

Check you have the proper valves fitted too.

[Bullet Whisperer]

Just welding around the inside circumference of the old valve seat should be enough for it to fall out when it cools down, this also works for removing the outer races of roller bearings, when they can't be drifted out. Heating the head and freezing the new valve seat should allow it to drop into the head, but you only get the one go at it [you probably would be looking for a couple of hundred degrees for the heat]. I changed the valve seats in several individual cast iron cylinder heads for a big MAK diesel some years back and in that case we boiled the heads in a big vat of water and put the valve seats into dry ice. It is a good idea to have a good mandrel handy to hold and insert them, though, because if they drop half way in and stop at this point, that can be a problem. I could give contact details for the guy who does my rebores, regrinds and sometimes, valve seats, but being near Lampeter, he is probably too far out of your way! Cheers, Paul.

[slowmo]

Thanks Chaps


I will do some phoning around the supplied contacts and find a box to put it in. Think I would rather send it to an outfit with good experience than risk the head with somebody local keen to 'have a go'.


Ta Slowmo

[The rider formaly known as Lone Rider]

Google search "Cylinder head repairs (your town)"