valve , piston cleaning +head

macfreebe · Post by **macfreebe** » Thu May 12, 2011 7:38 pm

Hi everyone anyone know whats the best way to clean valves + piston face +head as mine is needing done as there is a build up of something on them [like suit].Also after cct fecked ,bent 2 intake valves do u need 2 remove valve guids when replacing new valves or r they ok ?

benny hedges · Post by **benny hedges** » Thu May 12, 2011 8:35 pm

its best to replace the guides and seals if you can m8... but you can get away without.
depends how bad the valves were tbh.
if its ovalled the guides they will pass oil & the bike will be a smoker

wire brush on a drill is best for cleaning the carbon off, followed by solvol on wet n dry if you want it shiny!
a bit of carbon does no harm tho... actually helps combustion

Miztaziggy · Post by **Miztaziggy** » Thu May 12, 2011 9:06 pm

Doesnt too much carbon make it overheat though, when the piston fires it heats up the sooty spots?

macfreebe · Post by **macfreebe** » Thu May 12, 2011 9:08 pm

The guides r reluctant 2 move + dont want 2 force them any ideas

tony.mon · Post by **tony.mon** » Fri May 13, 2011 9:10 am

Guides are usually ok when this has happened, the bent part of the valve jams at the bottom of the guide and doesn't intrude far enough in to the guide to cause damage, form all the ones I've done.
Just insert a new valve and wiggle it, and compare to the other two (inlet) valves.
If there's not appreciably more wear, then leave them alone.

Any engine refurber, car ones will do, will have a press to remove the guides.
I've used a big drill press before, but it'll need to be a substantial one.

Oil leaking past them is caught by new OEM seals (don't bother with Silvers supposedly suitable originals, I had to send them back several times).
But preferably just install new ones if you're at all concerned about them.

Or just buy a secondhand head that has already been cleaned up for sale, and save the cost of new valves, seals and guides, plus any workshop cost if you can't do it yourself.

BTW, heating the heads first is helpful, stick them in the oven at full temp for an hour,
The ali expands more than the guide bush material.

And lastly an old bodge is to remove the guides, rotate through 90 degrees and re-install, as the wear is only in one direction; there's no sideways movement at all....

macfreebe · Post by **macfreebe** » Fri May 13, 2011 9:54 am

Thanks 4 that i think i will leave guides alone as they seem ok .At last have reached the stage where i can start putting bike back together .also one of the exaust bolts in the head has snapped of .I can get a self grip on it but havent tried it yet as dont want 2 do any damage 2 .Have soaked it with wd40 for a week 2 help .any tips u can tell us would be a great help thanks

benny hedges · Post by **benny hedges** » Fri May 13, 2011 12:04 pm

give the broken bit of stud a few sharp knocks downwards before trying to remove it, then 1/2 turn out, 1/4 back, like you're tapping the thread, just in case the thread winds out with the stud.
a bit of coppaslip on the new stud will stop it happening again
(personally i dont believe the stories that it caused threads to weld up... ive never had a problem with it)

Miztaziggy · Post by **Miztaziggy** » Fri May 13, 2011 7:01 pm

Definitely try hitting it with hammer to shock it, then get mole grips on tight and turn plus hammer at same time. Should come free. If not I posted a thread about same thing and put on another solution Inc a dremmel

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