Valve guide cracked how do you get them out?

[Suicidalbadger]

My 76 Jota has had its first major failure in 25 years, so not bad going.
But how do you get the circlip off the valve guide? Its got a bent valve/cracked guide but everything else looks OK.
This might show the bike

Any other tips whilst I'm in the rebuild appreciated I don't do many engine rebuilds as I mainly work with marine shafts, much less fidly.

 

[Dellortoman]

How did it get a bent valve? Did you miss a gear and hit 45,000 RPM?

Sorry, dunno about the valve guide circlip, never done that. But someone here will have the answer in no time at all.

Oh, by the way, welcome to the forum 

Cheers,
Cam

 

[breganzane]

They come out the other way, toward the cam side.  The circlip is not a retainer it is a 'stop' when installing.  The bore is very short in the head, so keeping them aligned when both removing and installing is important to avoid damage or misalignment.  Make a jig locating in the bucket bore.  More experienced types can chip in with the best methods.
Cheers
Steve B

 

[Suicidalbadger]

Brilliant, thanks for the welcome and information Dell and Breg. Looks like I may be getting the head sorted by Slaters as it would be a shame to do all this work and have valves that don't seat with guides not straight. Not sure what caused it to fail, it contacted the piston which is what bent it but piston looks OK, Its got Witt ignition so shouldn't over rev, but it also suffered a slipped timing back plate that sent the timing out whilst caning it. But otherwise it all seems OK.

Just out of interest do you have any idea how many old silver Jotas are still out there?

 

[sfcpiet]

No matter who does the head, the guides almost never line up with the seats, due to their shortness.  If you do manage that, play the lottery next week!

A good head shop will have the facilities to bore out the old guide to about 3/4 depth from the valve head side to reduce the pressure of the interference fit.  Heat the head and drift the guide out carefully.  No need to remove the circlip.  Bashing guides out without boring them beforehand usually takes out a fair bit of metal from the head... which in turn poses other problems.

piet

 

[Paul LeClair]

Brilliant, thanks for the welcome and information Dell and Breg. Looks like I may be getting the head sorted by Slaters as it would be a shame to do all this work and have valves that don't seat with guides not straight. Not sure what caused it to fail, it contacted the piston which is what bent it but piston looks OK, Its got Witt ignition so shouldn't over rev, but it also suffered a slipped timing back plate that sent the timing out whilst caning it. But otherwise it all seems OK.

Just out of interest do you have any idea how many old silver Jotas are still out there?

well, at the moment the early silver Jota's are rising high in the collector's eyes, an honest authentic example might well bring huge money, at least in the U.S. market, maybe in the $15,000 - $18,000 U.S. range. The info available suggests that maybe 5 early siver Jota's came to the U.S. sort of grey market through the late Lance Weil, I know of one expected to go to auction later this year with a hope of reachiing $18,000..... I don't know whether the seller is being realistic or not, but an early non Jota triple sold at auction several months ago for about $13,000 U.S. Very bad news for those of us who ride them and restore them to ride, it is getting harder and harder to find a restoreable example for reasonable money, or at least my own idea of reasonable money

as for how many may be in the U.K., if you are taking the bike ot Slater's anyways, you may want to pay Slater's the 25 pounds or whatever to authenticate yours as a "real" Jota, and they can tell you from their records how many there actually were.

welcome to this forum!

Paul leClair

 

[Suicidalbadger]

Last time I took it to Slaters just after I bought it around 86 (a great ride up from Bristol) they were surprised to see it still had the original cast Al (no plastic see through just black Alloy) front brake master cylinder. The only non original major piece is the witt ignition as the old wires had corroded out of the bosch coils, I've got the original seat as well as the one in the photo, and a z beam headlamp. But I have lost the tool kit

Slaters said any bike that had been dropped would usually loose or crack the master cylinder! so this was the most interesting piece! It's not showroom but then it gets ridden in the winter and snow sometimes (not by choice) it was just the only vehicle available.

 

[Reggie3cl]

I like the way that bike looks!  Anyway, you may also like to consider Keith at Laverdascozia for your head work, he'll do a top job.  

 

[CLEMTOG]

or even SEP at Kedgworth, who also do a great job, and in house, most do not, they send them to out workers, nothing wrong with that, but if you are removing and refitting yourself, then why not go direct, the encourageing thing is that SEP are the only ones that I have heard of recently who wont do the job unless they have the cams and their bearings etc, very encourageing is that, how do the others manage without?

I have been very diasapointed with certain cylinder head shop (s) in the past and got so fed up with poor quaity work, that I bought a brand new head, the last one, that he had, not not him, it was Toddy

If another new old stock, still in factory wrapper head came up under ?1000, I would buy it.
CLEM

 

[laverdakeith]

No matter who does the head, the guides almost never line up with the seats, due to their shortness.  If you do manage that, play the lottery next week!

A good head shop will have the facilities to bore out the old guide to about 3/4 depth from the valve head side to reduce the pressure of the interference fit.  Heat the head and drift the guide out carefully.  No need to remove the circlip.  Bashing guides out without boring them beforehand usually takes out a fair bit of metal from the head... which in turn poses other problems.

piet

 I do as Piet does, hog the guts of the guide out before removal. After pissing around making individual guides for individual bores in the past I now ream all guide bores to a nominal size using a hardened and ground pilot I machined up which locates in the cam follower bore, this ensures the bore for the replacement guide is re-formed concentric and parallel with the follower bore (how the head was machined in the first place) and I can guarentee the interferance fit on all guides is the same. I have guides made from Colsibro with the exhausts machined to accept stem seals which I fit using a guided mandrel after first cooling them in liquid CO2.  Maintaining concentricity here is critical as your valve seats are a finite resource and any slight error on the guide fitment compounds into extra material removal from the valve seat.
  It should not strictly be necesary to send cams etc. as anyone who is familiar with a Laverda head will have a record of acceptable max and min stem heights.


    Keith.

 

[Paul LeClair]

here in western Canada machinist specialists with a knowledge of Laverda heads are non existent. For worn guides, rather than have a Laverda head completely butchered, I have been using bronze valve guide liners......

http://klineind.com/home.php?cat=253

you people with easy access to Laverda machinist specialists have no idea how lucky you are! Support your local Laverda specialist!

Paul LeClair

 

[Grant]

Don't they have a postal service where you live?
I have to post my cranks or heads thousands of km to get work done on them.
Nothing in Spain of note for Laverdas.

 

[mcnicol]

Grant

Paul's in the same boat as me, since Lance Weil had his terminal accident, except for Scott Potter and Wolfgang there's nobody who knows Laverdas in North America. Scott's not set up to do everything that might need to be done, and I don't know about Wolfgang for esoteric stuff like this. So we have to send stuff to Red in Australia (when he's home), or Piet in Germany and now Keith in Scotland. All good choices, but it does add significantly to the cost, plus there's the risk of the stuff getting damaged or just disappearing in transit. Ah well, the joys of owning fine machinery :.
JLO must know people he uses in Europe; JLO, want to give us a lead for experienced Laverda machinists who work for less money than Rupert Murdoch?

Ken

 

[phil37]

Whilst the head is out , SuicidalB, pay extra to get the 8mm cam pillar stud threads helicoiled or timeserted - they can easily strip on re-assembly. BTW - I have a Silver Jota with all cast front brake master cylinder - anyone wanting to bid $18000 could be the proud owner of it! - Regards - Phil

 

[nick7]

Hey Clem,
I think you are a bit optimistic at just?1k for a new old stock head....you remember what I paid for that RGS one sat in Slaters for 25 years?! It may be of interest to mention I sent even that to keith before fitting...3 angle valve seats cut,timecerts, exhaust guides adapted to take seals, new billet inlet stubs etc.Sweeter than a sweet thing now..Do't know where Slaters will send your head, but if he can fit you in,Keith would be my choice.
Nick7

 

[Reggie3cl]

Andy Wagner is showing a new head at 1453.41 Euros (why the 3.41??) so a wee bit over a grand Sterling.  Another item on my big long Laverda shopping list... :

 

[Paul LeClair]

Whilst the head is out , SuicidalB, pay extra to get the 8mm cam pillar stud threads helicoiled or timeserted - they can easily strip on re-assembly. BTW - I have a Silver Jota with all cast front brake master cylinder - anyone wanting to bid $18000 could be the proud owner of it! - Regards - Phil

Hi Phil

naw, your bike is missing the original Italian air from the tires, the rear grab rail, and has a really funky swingarm, the collectors would be turning up their noses if you offered it at auction, thank god......

Paul LeClair

 

[phil37]

Being picky Paul - but the grab rails weren't  used 'till 1979 ish on the 1000's - making Suicidal's SOOOOOOOOOOOO non-original - Regards - Phil

 

[Davo]

Hey, I've got 3 all ali master cylinders if anyone wishes to make their bike "original". One of them is the original from 1976 depsite the bike having been down the road a couple of times. $5000 each reasonable??