Accelerator pump issue - help please!

Thanks, I'll bear it in mind. I'm told M&S in Newcastle know Laverdas also, but I'm keen to fix any issues myself if I can. That way I'll get to know the bike.
 
the accelerator pumps are not and were not your issue, my 1200TS (which yours was when new) has not had them for at least 35 years and maybe 200,000 kilometres, there is no delay on throttle response, she goes like stink and will rev all the way from 1000 to more than 8000 if you dare risk a blow up, she is on very high mileage and an engine built as a temporary fix from a box of used spares, so not in the best of health, but for sure you dont need those acel pumps, my feeling is that your ignition is not advancing as the revs build, if its got the stock BTZ still fitted, there is no advance curve, but simply a step at about 1800rpm or 25000rpm depoending on how your trigger gaps are set (they are not realy adjustable but can move) of course getting the carbs cleaned was a very good thing, but the internal channels are very often missed or partially missed, its easy to clean removed jets, but the passages that they flow through are just as important and veryoften not cleaned well or not at all!
CLEM
 
Finally got around to having another look at the Mirage.

Solved the gearchange issue, which was a worn part in the gear selector mechanism, so I took a look at the carbs again.

My bike has Jota exhausts, no air filter, and standard Mirage 145 main jets with K14 needles. The carbs look in great shape as they've been ultrasonically cleaned by a carb specialist. I was given a set of K1 Jota needles so I reckoned it would be worth trying those. What a transformation! No more flat spot at 4-5000 rpm and it pulls strongly all the way through the range. Result!

Still a few little bugs to sort out, such as a significant oil leak on the right side of the engine, which seems to be just a badly fitted gasket, but I'll need to take the alternator off to fix that. However, I think I'm going to enjoy owning a Laverda triple once these teething troubles are sorted out.
 
The jetting for mains their days is around 125 or slightly less. 140s were used back when fuel was way different. The needles are what most use now K1s. Do a search here for air filters, there are opinions that can be made to fit the airbox.
 
Good stuff (y).

Just as a passing comment, because others will know better, but I note that Jean-Louis' Mini book lists a K1 needle plus 130 main for the Mirage as opposed to K14 and 115 main for the cooking 1200 and TS.
Mirage.jpg
 
Still a few little bugs to sort out, such as a significant oil leak on the right side of the engine, which seems to be just a badly fitted gasket, but I'll need to take the alternator off to fix that.
When you have the inner case off, carefully check for distortion on the cover. The space between the two lower bolt holes is larger than ideal and the case can bow. An engineering shop should be able to skim it flat.
 
So it will run too rich at large throttle openings on the 145 main jets? I'd better order some 130 jets then. Or 125, or 120?
Incidentally, the cams are marked A/11 if that makes a difference.
 
When you have the inner case off, carefully check for distortion on the cover. The space between the two lower bolt holes is larger than ideal and the case can bow. An engineering shop should be able to skim it flat.
Yes, I think that's the problem. The gasket has visibly blown outwards between those two lower bolt holes, hence the leak.
 
Yes, I think that's the problem. The gasket has visibly blown outwards between those two lower bolt holes, hence the leak.
Once skimmed it should be good for another forty years.
Be careful to get a shop which will remove the absolute minimum required, not just chop 30 thou, or more, off, which could compromise the starter gear shimming,
 
<snip>
Incidentally, the cams are marked A/11 if that makes a difference.
Jean-Louis (see below) and Mick Walker say a Mirage should have 4C cams, but Ian Falloon says this was downgraded in 1980 for the Mirage TS to A11s. So I dunno ...

Best wait until some experts come along to confirm or deny ;)

4C.jpg
 
My bike was imported from the USA some twenty years ago and originally wore '1200' badges on the side panels, so it's really a TS with Jota exhausts, hence the A11 cams rather than 4C cams.
 
My bike was imported from the USA some twenty years ago and originally wore '1200' badges on the side panels, so it's really a TS with Jota exhausts, hence the A11 cams rather than 4C cams.
Ah, that changes things ...

I have a spare parts page entitled "Varianti per 1200TS (Mirage) versione USA" which shows quite a few differences from the 'standard' Mirage.

Main jet 112
Idle 64
Needle K28 (3)
Atomiser 262 AB
Slides 50/3
A12 (!) cams
... and so on.

The part numbers for the cans are 63 503 184 and 185. Are these 'Jota' cans?
 
your bike was obviously a series 1 1200TS when new,
tell us the four digit VIN number, mine is 2608, yours will be close.
most TS types are are serieds 11.
the series 1 as supplied ex factory did have some changes oiver other triples, the side panels, frame trims (under seat) and the tail piece are all correct for a TS, it should also have engine panels and a handlebar fairing. What is very often missed, and frequently changed when the motor is apart, is that factory fittment was the big valve Jota head (not the Corsa/SFC head). The pistons will be flat top 7.8:1 Mondials and the stock cams were the very common All type. Jetting is not the same as it was back in the early 80's (so ignore what you read in books) due to the change(s) to the fuel ending with what we have today, Mine runs very well on E10 but she has been dynoed to take into account a few changes and the modern fuel, a good test for any triple is the abiluity to re-start a hot or warm motor simply by just pressing the starter button, choke should not be needed, but frequently is! there should be no need for blipping the throttle, it should start just by pressing the starter button (with a broom handle if you like) and it should tick over for a fortnight before you even need to get near it, most do not, one dealer even sent out a leaflet with every triple that he serviced that said, "half choke is needed to re-start a hot or warm engine, this is normal" no its not, it indicates that low end of your carburation is wrong, and if it wont run flat out in top gear (guitar string tight throttle wire) then your main jet is wrong as well, I have seen several different bikes that on a "top speed run" the rider will realise that the motor is faltering/flagging and drops the throttle a tad and its back in, this is not normal. My advice to you is to reditch the accelerator pumps and go to the dyno for a run or five. Good and clued up dyno operators will ask you to temporailly disconnect them anyway so as not to "screw" the readings.
CLEM

hers mine owned for 43 years/250,000 kilometres
click on the photo for a full screen view.
 

Attachments

  • Picos 2018zoom.jpg
    Picos 2018zoom.jpg
    340.6 KB · Views: 15
Back
Top