Valve spring broken?

Very possible.

RH exhaust ?


this might help

viewtopic.php?f=5&t=11115

83036028044

http://www.partspitstop.com/KeywordProd ... 3036028044

hello Idle

http://www.ebay.co.uk/itm/HUSABERG-DUAL ... 2219wt_698

a common enough problem with the original conical springs. I sell the above sets with fitting instructions and never had any trouble with them so contact me if you are interested. mine are slightly softer than the KTM ones.

regards

Taffy

come on now I can't let that one pass up "never had a problem" simply isn't true viewtopic.php?f=5&t=15236

for anyone who wanted to spend double the price on valve springs Kibblewhites DVSK has titanium retainers and something thicker than 0.1mm fork shims to put under the springs.

Idle I know the feeling.. where to stop.. .if the piston is OK and you leave the cases together it should make it cheaper but only short term

Same side spring happened to me. I seem to think it something to do with decomp. I justed replace both exhaust spring have not had a problem since. Funny i took the head off mine the other day and relapped the valves back in. My mates a fulltime head porter for race cars/bike basicly any motor. Him and his boss commend about how good the ports are as standard then we got talking about duel valve spring with lower seating presures and they both said the same" why would you want to go duel with lower seat presures". Most of the engines are going toward conicals now days they said. They also comented they have never seen a motor make more horsepower with lower seat presure only high horsepower with high seat preasures. Valve float kills any motor very quickly they said. Food for thought.

It's true, I've never had one problem with my DVSKs. 100% reliability.

fork shim? another accusation without any foundation. quite a list....

get a life

Thats great Idle

glad to be able to help, I have a set of the ATV springs on the way, a new conical set and a kibblewhite DVSK ($150 on eBay) to compare weights and seated pressures with, will update the thread above when they arrive.

FWIW and just quickly though AVOID anyone selling valve springs claiming the OEM seated pressure to be 100Lbs it is much much lower...

Taffy said:

It's true, I've never had one problem with my DVSKs. 100% reliability.

fork shim? another accusation without any foundation. quite a list....

get a life

Click to expand...

another misinterpretation of a simple one line sentence resulting in a paranoid delusion from ye olde welsh lunatic

I did not accuse anyone of using fork shims I pointed out that the shims you supply are the same thickness as fork shims.

get some glasses

birdwoodburg said:

Same side spring happened to me. I seem to think it something to do with decomp. I justed replace both exhaust spring have not had a problem since. Funny i took the head off mine the other day and relapped the valves back in. My mates a fulltime head porter for race cars/bike basicly any motor. Him and his boss commend about how good the ports are as standard then we got talking about duel valve spring with lower seating presures and they both said the same" why would you want to go duel with lower seat presures". Most of the engines are going toward conicals now days they said. They also comented they have never seen a motor make more horsepower with lower seat presure only high horsepower with high seat preasures. Valve float kills any motor very quickly they said. Food for thought.

Click to expand...

If I recall correctly Thomas of enginehardware was adding preload to the conicals, 1mm I think to reduce breakages by moving their resonance.

you're right Birdwoodberg about conicals, seated pressure etc and FWIW I didn't notice any extra power going to dual springs, the first ones I got actually increased seated pressure.

its now generally accepted amongst the speed talk gurus that the main function of the dual valve springs in canceling out resonance is due to the friction between the inner and outer coils. while good for spring life it creates extra heat and dual springs almost always increase the reciprocating mass. anyone who claims dual valve springs reduce running temp should work for a marketing company. (or be able to provide actual proof)

I should be able to setup a spintron test to show the difference in power requirement between all the springs should be fun I want to check out the oiling circuits in action too.

Idle yes I'd check at 10 hrs

birdwoodburg said:

Same side spring happened to me. I seem to think it something to do with decomp. I justed replace both exhaust spring have not had a problem since. Funny i took the head off mine the other day and relapped the valves back in. My mates a fulltime head porter for race cars/bike basicly any motor. Him and his boss commend about how good the ports are as standard then we got talking about duel valve spring with lower seating presures and they both said the same" why would you want to go duel with lower seat presures". Most of the engines are going toward conicals now days they said. They also comented they have never seen a motor make more horsepower with lower seat presure only high horsepower with high seat preasures. Valve float kills any motor very quickly they said. Food for thought.

Click to expand...

Birdwood your mates have got this slightly wrong. cam profiles, acceleration ramps, valve assembly weights are all to be put into the equation. if a valve is to be stopped from floating the spring pressure has to be raised and clearly their engines struggle with this - so they simply need MORE pressure. the Husabergs don't. you can even use the old wicked '53' cam with them and they still don't float - they made all the 400 and 470s have valve float with their single springs! this smashed the seats up. it did it in as little as one race for some.

as for info about resonances and DVs being some kind of new idea well I got it myself from technical college. that is 1977.

personally, I've only ever said that I felt the difference at low revs and since when did a most people give a SH** about it for RR or some such. I ask you - I mean let's get the facts straight here can we? all these guys want is top line B.H.P and then what is underneath is second.

DVS is a better set up than SVS - end of. the problem is finding the space and I've only ever done that with my first springs and the kibblewhite's which were a very strange design.

I've weighed the 'Ti' Kibblewhite caps and they are no lighter as they are probably made of a Ti ALLOY and not 100% Ti.

I'd invite anyone reading this who has ever fitted my kits or Kibblewhite's or anyother some such to say just how much easier it was to compress the DVs after fighting to remove the SVs set-ups?

ANYONE OUT THERE WOULD LIKE TO SAY HOW MUCH EASIER IT FELT? it would be nice to get THAT part sorted first.

regards

Taffy

Taffy they were refering to springs only not cam ect. Float was brought up and said any float kills a engine real quick and that why they would go for increased presure. I have a 650 so rev's shouldnt be a problem to bring on valve float. 450's might but no expert on this. Not sure what a 450 rev's too.

I'd invite anyone reading this who has ever fitted my kits or Kibblewhite's or anyother some such to say just how much easier it was to compress the DVs after fighting to remove the SVs set-ups?

ANYONE OUT THERE WOULD LIKE TO SAY HOW MUCH EASIER IT FELT? it would be nice to get THAT part sorted first.

I got one of Taffy's DVSK fitted.
No doubt about the motor being easier to kick (or hand) over slowly to find TDC. Not as much clatter from the top end. Definatly easier to fit than single springs. No probs fitting (once the fitted length issue was cleared up, that is cleared up not sorted Bushie).
Be interesting to figure how much less turning resistance is required to open/close valves with dual verses single springs. There was a theory a few years ago that suggested 8-10% of the power generated is used to turn the camshaft depending on lift/profile.

Any knowledgables got any input (without turning it into a slanging session).

Idle said:

As far as power is concerned, I did chip/scrub the carbon off the head and valves (230 hours worth) so I'm sure that's why it has more snap and power off idle. The slightly weaker springs may have helped the response just off idle.

Click to expand...

why are you sure about this?

it isn't the carbon. it is your the valve springs Idle. eace:
you just don't get it do you. seated pressures down 40%, people quoting it in front of you as to why but no, Idle says I scrapped some carbon off so THAT is the difference!

but at least you not biased are you..... it was your opinion.

regards

Taffy

Idle try carby cleaner works a treat on carbon gone in seconds.