Strange valve clearances problem.

[Neosophist]

There is still a few mm to play with but for optimal performance you should have them set properly.

Did you balls up the first attempt? Guess there is no way of telling that.

How / where are you measuring the clearnace from.

Why are you replacing the cams / valve stem seals etc? is it broken?

[VFRkieran]

Thanks for the replies its a big help!

@ Neo Im sure i got them right on the first attempt but it looks like i must have gone tits up somewhere, i have all the time in the world to make sure it is absolutly spot on this time round so i will make sure its perfect.

I was measuring the clearance between the rocker arm and top of the shim.

Im swapping the cams for NC35 ones because i got them for nothing in a blown motor and i wouldnt like to sell them and make money from someones good will, so the way i see it its worth swapping them even for the relativly small performance gains. Valve stem seals are being replaced just for peace of mind, i have 67000 km on the clocks and it is burning a small amount of oil, other than that its been trouble free for the 25k ive put on it over the last 18months so i am now giving the whole bike a good refresh over this winter.

@ Mark I was under the impression that lapping them in would reduce the clearance even more, luckily i have 32 valve shims so hopefully i will be able to get the clearances bang on without having to shell out for any others.
I think i will set them at the looser end of the scale if you and tony think its a good idea too, a big reason for doing all of this work is how much nicer the bike should feel when its completed i have a feeling this is the first time the heads have come off in 23 years! I did plan on removing the casting flash but to tell you the truth i wouldnt know what to remove! If you have any pictures or could explain what and where that would be brilliant!

@ Pip and Tony My thinking exactly is that they shouldnt have closed up by this much in half the recommended interval for the valve clearance check, so i must have made a mistake somewhere! I have 2 explanations for this, either my maths was wrong and i infact tightened up the gap rather than increasing it.

Or i have been measuring them wrong this is where i need a little clarification, with the feeler guage am i correct in thinking i should slide it right through the gap or do i just poke the tip of the guage into the gap at the edge of rocker arm and shim rather than pushing it all the way through? Hope ive explained that properly, im sure the way i was doing it (pushing the feeler guage right through) is correct, but the fact that the clearances have tightened up so much is making me question everything.

Hope that wasnt too long winded for everybody, apologies for not replying earlier and again the help is massively apreciated!

[CMSMJ1]

Aye.. you push in so it slides in, but not too freely and not so that it bends the gauge! Think shagging...

casting flash wise - you can see it in the heads - either side of the inlet tract you see roughness where the heads came out the mould. you are only removing this. nothing radical like a porting job, but just cleaning the crap left over. easy to do.

[VFRkieran]

Aye.. you push in so it slides in, but not too freely and not so that it bends the gauge! Think shagging...

casting flash wise - you can see it in the heads - either side of the inlet tract you see roughness where the heads came out the mould. you are only removing this. nothing radical like a porting job, but just cleaning the crap left over. easy to do.

Haha i like that way of describing it, i have definatly been measuring them correctly then.

I thought that was most likely what the casting flash was, should be easy enough to make a bit of an improvement there, thanks for clearing that up.

[porndoguk]

what's the Craig with head gaskets then keiran?

Need to get my heads finished this winter.

[VFRkieran]

what's the Craig with head gaskets then keiran?

Need to get my heads finished this winter.

Can still get them new from david silvers for around £60 the pair. Also on valve steam seals Rick o tells me honda have put the price up to £9 pound a seal! He is trying to source some good quality aftermarket ones from Versah japan which he says will be up to OEM quality. Allthough david silvers still have OEM seals listed at 6.75.

[porndoguk]

I was hoping for a cheaper option but not on quality for the gaskets,

I have a set of heads that I started removing the casting on, and all the studs/threads are mint as my rear c1 has been drilled and tapped to M8, and the front c4 had a snapped stud and a previous attempt by a former owner ended up in a fuck up so that's why I was going to change my heads eventually, I currently have my front header lockwired up (Bodged)

Ps what's the Craig was meant to read Craic but auto correct spazzed out on me lol

[VFRkieran]

I think it will be a struggle to find some head gaskets as good as OEM quality for alot less money TBH, Im just going to bite the bullet and spend the money on OEM stuff hopefully i will have alot more trouble free miles before i eventually decide to get the whole bottom end professionally rebuilt.

I got quite lucky all of my studs bar one came out with ease, the other looks to be a little rusted but i think with a bit of persuasion it may come out without breaking.

[speedy231278]

I'd not touch aftermarket head gaskets with a 50 foot pole. Aftermarket engine gaskets have a bad reputation, and somewhere on here not very long ago someone posted a thread where they'd had HGF after an engine rebuild, and the cause was a crap aftermarket gasket letting go after a handful of miles. Quite frankly, £60 is quite a lot for two small gaskets, but work out what your hourly rate at work is, then multiply that by how much time it takes you to strip and rebuild the top end. I bet your time to do a second rebuild is worth more than the saving on cheap gaskets...

[VFRkieran]

I know exactly what your saying speedy which is why im planning to use OEM gaskets because it is such a crucial part and if it goes wrong its going to cost alot more than you save! I am still undecided on Valve stem seals however I spoke to Rick Oliver last night and he said that Versah are going to supply him with some gasket kits and valve stem seals which he thinks will be up to par with the OEM stuff, not sure i want to be the guinea pig though...