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Well I have decided to go the whole hog with my 1200 over Christmas. While I have the heads off to replace the gaskets, I will remove the valves and grind them in and put in new valve stem seals which will stop the smoking on start-up.
Thing is I have never grinded in valves before and more than one person has suggested that the GL1200 has hardened valves and seats (for running unleaded) and that they can't be ground in and need to be cut with a machine instead.
Has anyone out there managed to grind in the valves on their 1200 and if so can you tell me the way to go with this? Thanks once again.
 

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When you have the heads disassembled just use a hand lapping tool to check the contact with the seat. Use some bluing to help identfy any problem areas. If the valves are burnt you may have to replace them, but, I find this to be rare. You may have to take the heads to a machine shop if you require the 3 angles reground as I did on my 84 1200. I also opened up the exhaust ports on my heads as big as possible and matched the exhaust ports to the gaskets for a little better fuel economy and slightly more horsepower.

(Just in case you don't know, make certain that all the valves stay organized so that they go back into their proper ports, if you mix them up you could have problems.)

Vic
 

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Goldwinger1984 is on the mark.. Very good advice..

Inspect the valve guides for wear prior to lapping the valves by dissassembling the springs, keepers & seals, and just wiggle the valve from side to side while it's in the guide.. The amount of freeplay should be negligable if any at all. If you still wish to hand lap the valves, start with a course grit lapping compound, a few drops of oiland work the face untilthe surface finishesare uniform all around on both the seat and valve face.. This indicates full surface contact.. Then, finish the job with a fine grit compound and continue lapping until the face surfaces are nice and shinny. Be sure to clean all surfaces, including the back sides of the valves and stems before assembly.Use plenty of engine oil during re-assembly. Most of all,,,,,Have Fun!!!:goofygrin:
 

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The 1200 valves are easy to grind in. Grinding paste will bed in even hardened valves and seats, just takes a bit longer than on unhardened items. You can use a drill on low speed to grip the thin end of the valve (put tape on the end first) and pull upwards as you spin the drill. That will do the job very quickly, but you should only use a drill if there is severe pitting that will take a while to remove and you will need to stop often to check progress before you grind too far. Also if you use a drill you will need plenty of oil down the valve stem to prevent wearing the guide out.
 
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Hey Eamonn1200, :action:Now you have just recieved tech advice from three (3) "Guru's" from (3) three different countries, :waving: so you cant go wrong. :clapper:Thats what this forum is all about. Good luck with the job over xmas. :santahat:

:santawaving: :18red: :santawaving:
 

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Yes Redwing. I decided to get prepared this time, all the questions answered before I did the job. I'm off for 2 weeks over Christmas so once the turkey & pud are settled I will be able to get stuck into the job. Thanks to everyone for your continued help. :waving:
 

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Don't want to get in an dispute with Jason, but using a drill seems a bit brutal and might grind away more material than necessary. I'vealways used the old suction cup on a stick for hand lapping valves. For the best results the lapping should be done in both directions. Put a very light layer of compound on the valve face or seat, set the valve down on it's seat, put the lapper on top and turn the valve around once or twice to distribute the compound and then go to town, like you're trying to start a fire twirling a stick between your plams. You don't need much pressure. Lift the valve up a little bitonce every ten or so twirls during the process to pull the compound back in. You can get a good idea how well things are shaping up by looking closely at the faces of the valve and seat, if you have compound that's dyed. It really doesn't take all that much to lap them in, especially if the valves and seatshave been reground. Use the coarse grade compound sparingly and do most of the work with the fine. Make really, really sure that all compound has been washed out, it just takes a trace of it in the guides to make all kinds of nasty mischief.
 

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The drill does work, provided its a variable speed and better if its reversable as well. I've seen it done in engine shops, ie low speed from the drill and not too much pressure and someone dripping oil from an oilcan down the guide for lubrication. You only need a drill for well worn valve seats, you wouldn't be using it for a light lapping where there is no pitting. The trick is to know the difference when you examine the parts.
I guess it's one of those unofficial "tricks of the trade" that gets frowned on by the teahers but which works all the same.
 

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I'll probably do them by hand as I'm not experienced enough to trust myself with a drill. A car mechanic friend told me to do the lapping before I installed the stem seals so as to stop them getting damaged. Hadn't thought of that, we live and learn. Thanks for all the help once again.
 
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