valve clearance closing up

sfcpiet said:
In over 30 years of Laverda triple ownership, never have I experienced problems with fuel feed.  Taps, hose and carb unions are all up to the job.  Never even considered swapping them for something else!  Hose routing only has an influence if it is draped OVER the tank...  

The Breganze boys got it right from the start.

piet
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Hi Piet,

as you know, I had fueling issues which lead to the sized valve on my 1000 SFC (which still needs a fix...  ;) ). I had that on the Jota, too, and any time the tank get's empty, there is more and more air in the fuel-lines. And mine just point down - maybe that's the fault then...  :LOL:

The moment you get below reserve and corner a bit (not hard, just a bit...) the snorkel of fuel tab that is higher (on left corners the right one) is sucking air. that is a fact at least on all my bikes. even going to reserve does not fill the fuel-lines fully anymore, it feels as if the fuel just dribbles into the line. I have tried several different routings, several different pet-cocks, made sure they are not blocked or water is the tank etc. - I had it always and ever. I had it with Dell'Ortos, I had it with Keihins - no difference.

The only way to avoid it is to keep the tank full.

To the theory of the fuel stays at the ground even in corners: I understand the point of centrifugal forces, but they are not applying the moment you enter the corner, they are only applying full at the center of the corner, increasing on the way from entering the corner to the center and decreasing from the center to the exit. Fuel still can move a bit on the way there and out. I can not suggest to look at the fuel lines while cornering, but I had those issue several times, believe it or not.

Oh- and lets not forget the situation when you brake hard and all the fuel splashes to the front of the tank or up- or down-hill rides with limited fuel in the tank. Maybe I am doing something wrong here, I don't know, but it happens on all my bike except for the 750 Formula maybe...  :D
 
your exhaust valves are closing??
My RGA had some valve clearance issues. The valves looked VERY overheated. I changed the oil on the bike and the clearances closed more.
AFTER that I learned that the oil cooler lines need to be bled beacuse they exit out the bottom instead of the top.
Yes, I learned that after I had the shims ground.
If you don't bleed the oil cooler air gets trapped and the head overheats. ugh.

DungeonMaster
 
Hi DM my valve clearance closed up as the valvehad been ground so far that there was no margin left and as it heated the valve head mushroomed back in towards the seat the problem has since been sorted with a replacement valve.
Two items raised here bewilder me a bit the first is the fuel feed topic surely bikes are going to run onto reserve from time to time my Laverdas have done it thousands of times and never done any damage also I have just come back from a 3200km ride in 3 days and couldn't help but look at the right hand fuel line from time to time and noticed quite a lot that there was an air bubble in the fuel line (even after I kicked the petrol line union down a bit as suggested earlier in this thread, at times the engine was continuously running at over 4000 rpm for up to 2 hours with no sign of fuel starvation.
The other item is this bleeding the oil cooler I believe the oil is pumped through the radiator at low pressure Dungeon Master are you sure there wasn't a restriction on the outlet side of the oil radiater that stopped oil flow to the head as I am certain that oil coolers wouldn't have to be bled otherwise all these bikes that get ridden irregualrly would have oil cooler lines getting cracked all the time, I would be interested in other opinions here.
Just my opinion,
Regards
M
 
Doesn't the oil drain out of the cooler whenever you shut the motor off?
 
DungeonMaster said:
your exhaust valves are closing??
My RGA had some valve clearance issues. The valves looked VERY overheated. I changed the oil on the bike and the clearances closed more.
AFTER that I learned that the oil cooler lines need to be bled beacuse they exit out the bottom instead of the top.
Yes, I learned that after I had the shims ground.
If you don't bleed the oil cooler air gets trapped and the head overheats. ugh.

DungeonMaster
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Sorry mate, but that's bullshit...  (cheers)  :D

The cooler does not drain completely when the engine is shut off.  Proof?  Take it off and watch 1/4 liter oil drain out when held sideways... if you have the correct type fitted that is.

The cooler is actually filled from the top, the pipes go to the top of the cooler internally.

Even if it were totally empty, the oil pump would fill it before any overheating could occur, Lav pumps are not THAT puny... I have never bothered to prime the cooler before re-fitting.  If the pump doesn't manage, you would suffer cam siezures before the head/valves would overheat.  Wise to check cooler temp before giving the bike the berries, gives you an idea of what's going on in terms of oil circulation.

A simple oil change will have no effect on valve clearances.  Your valves closed up further because they were already knackered.  Once the deformation starts, it will continue till the head either drops off or the valve is replaced.  This can also happen to inlet valves!

Primary reason for burnt/stretched valves is incorrect float level, even a partially blocked fuel line will flow enough for the engine at WOT.

piet
 
That rarely happens Grant.

Even a badly scored pump will manage to fill the cooler and even circulate some lubricant, well, sort of...  You wouldn't believe what I've found in some pump housings over the years. :D

piet
 
Over 250,000 kms on the yellow peril; never bled the oil cooler, never bent or burnt a valve or anything like that, what have I done right (dunno)
 
Over 250,000 kms on the yellow peril; never bled the oil cooler, never bent or burnt a valve or anything like that, what have I done right  (dunno)
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You rode it regularly (had to with that kind of mileage). Laverdas (especially triples) need to be used to stay in good fettle.

 
Think you nailed it Poffer, always like to ride at least once a week to burn any moisture out of the engine and exhaust.
I honestly can't understand how some folk have problem after problem and mine keeps soldiering on.
 
Think you nailed it Poffer, always like to ride at least once a week to burn any moisture out of the engine and exhaust.
I honestly can't understand how some folk have problem after problem and mine keeps soldiering on.
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S'true  :D  The best Laverda I ever had (more years ago than I care to admit  ;) ) was a 1977 Jota. It had been ridden hard to within an inch of its life and had 48k miles on it when I got it (it was quite young then). I carried on the tradition - thrashed it and put miles on it.  When I came to sell it, it sold in a heartbeat, as it ran like a dream  8)

Pete
 
poffer said:
Think you nailed it Poffer, always like to ride at least once a week to burn any moisture out of the engine and exhaust.
I honestly can't understand how some folk have problem after problem and mine keeps soldiering on.
Click to expand...

S'true  :D  The best Laverda I ever had (more years ago than I care to admit  ;) ) was a 1977 Jota. It had been ridden hard to within an inch of its life and had 48k miles on it when I got it (it was quite young then). I carried on the tradition - thrashed it and put miles on it.  When I came to sell it, it sold in a heartbeat, as it ran like a dream  8)

Pete
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Treat'em mean >:( - keep'em kean :D
 
what you can get is emulsification in the top of the cooler if the bikes not ridden alot this can cause prombles,take it off clean it back wash etc as said before the internal tube in the cooler goes close to the top and emulsification here can cause big prombles ,on a weak pump in this case the oil will mainly go to the chaincase causing a shortage at the top end,infact i;ve sometimes wondered if blanked off ( to chaincase) would it improve the oil flow to the top end (i don't believe it was there on the early bikes ?)  :D :D :D :D :D :D :D :D :D :D
 
you are right Ray it wasnt
but dont forget that the rubber hoses can collapse and can cause total oil circulation failure, you know all about that one as I recall.
CLEM
ps wanna bed in the tin tent this weekend at lydden?
 
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