What did you do to or for or with your Laverda today?

They had a static display of racing bikes with ‘start-ups’ on the Douglas Prom this evening as part of the MGP centennial celebrations.
Rune and I took Tom Quaye’s old 840 race bike and his Formula 500 which drew in the crowds when he fired it up a couple of times. All-in-all a good day today.
 

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Checked the tappets on the SFQ - exactly where I set them prior to its maiden voyage - about 3 tanks full ago (GPS speedo had issues!). Includes lots of high rpm hitouts on the road and dyno. Nice to know there's no soft seat or valve tip shit going on (Rotax adjusters BTW).
 
Fitted a new Bosch M4F54 30 amp/hr battery (£83.24). The previous Banner Starting Bull (£63.99 in '21) only lasted 20 months, before dying.
Its, same make, predecessor(£56.02 in '17) made 58 months. Before that a Westco 53030 lasted 18 months (£91.99 in '15
Best I've ever done was a Yuasa, which lasted 9 years!
 
got two Yuasa's a year or two ago for a tenner each, you might remember you named Dave Finch the truffle sniffer, one failed fairly quickly and wouldnt even do ride on mower service, the second one is still going strong.
Anyone else still using them?

I seriously dont think that 240CCA is needed, (experts please respond) I have salvaged a Lithium batterry from a KTM that Tom dismnatled its weighs jack shit, (580gms) is about the size of two fag packets and has 140CCA, might give it a try

CLEM
 
FWIW, not so much the CCA as the leading parameter, it is the actual battery terminal volts as the high cold crank amps are drawn. Battery voltage is a square law function for common inductive discharge ignitions, mentioned this previous. Lets say ignition 3 amps is drawn from a 12 battery R=E/I or 12/3=4Ohms. P=E*I or 12*3= 48watts ( its the magnetizing current that does the ignition spark work, however ).

Repeat same calculation for a cold crank sag of say 9V at battery terminals, 4 Ohms at 9V= 2.25Amps following 9 times 2.25 equals, 20.25Watts. You lose more than 50% of the power for a 25% drop in terminal voltage. Much worse with every voltage sag at the battery terminals, let alone losses in the wiring and switches.

Series compound wound starter motor will work down to 6V as such, the ignition system not even close unless a DC to DC convertor is included.

Batteries these days should be considered consumables like tyres and oil ( coolants even ). Then even with higher cost batteries, no certainty that service life will be commensurate with higher purchase price, the charging system has to be very good.

CCA should be equated with battery terminal voltage, to be meaningful. Something i am able to do here with graphite pile battery tester.

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CLEMTOG said:
got two Yuasa's a year or two ago for a tenner each, you might remember you named Dave Finch the truffle sniffer, one failed fairly quickly and wouldnt even do ride on mower service, the second one is still going strong.
Anyone else still using them?
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Using Yuasa AGM had a good run so far, changed the one in the Jota only because it was more than 6 years old and didn't want to get stuck 700 Ks from home.
 
E662F94B-C5CC-46AE-8BD4-8DB387EDC361.jpegFound a dirty old bike at the back of the workshop that hasn’t seen serious use for a few years. Gave it a bit of a clean, will get it back on the road in October (likely to get snow next month) and see if I still like it. Otherwise could turn it into a bar leaner. BTW, has one of those yellow AGM Motobatts fitted November 2012 and starts a charm. Only battery I have tried in the Jota that gives good cranking.
 
this years 2 day excursion around the alps with the Jota was a little wetter than last years, had to turn back at the Großglockner, Brenner and Timmelsjoch passes due to land slips. Bike performed without a hitch of course, great trip. Was almost as wet as the run down to Breganze earlier in the „summer“
 

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laverda180 said:
this years 2 day excursion around the alps with the Jota was a little wetter than last years, had to turn back at the Großglockner, Brenner and Timmelsjoch passes due to land slips. Bike performed without a hitch of course, great trip. Was almost as wet as the run down to Breganze earlier in the „summer“
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Great roads, had a fat time doing them 4 years ago
 
CLEMTOG said:
I seriously dont think that 240CCA is needed
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It isn't, as John notes - you need volts as well as amps to get a successful start! But having said that, CCA is not a bad indicator of suitability to the task. A triple starter will take around 170A when cranking with a cold engine. Add in the effects of an aging battery with reduced capacity; poor charging regime; old wiring with increased volt drop and you're quickly running out of road. Not to mention a starter motor that's never been overhauled.
My old Odyssey PC680 sees a minimum terminal voltage of 10.4v when cranking and delivering 170A (which coincidentally happens to be its CCA) - voltage tends to rise once the engine begins to turn. Worth noting that CCA claims by some manufacturers are not reliable and spurious when talking about lithium based cells. I usually recommend a 16Ah lead acid battery as the minimum for a triple.
 
CLEMTOG said:
<snip>

I seriously don't think that 240CCA is needed ...
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Get yerself a 750 Zanè, Clem, and discover how every little bit of extra ooomph is most definitely needed! :giggle:

(Me dear old Corsa, on the other hand, will turn over on a AA (OK, I exagerate a bit). Bet yours does too ...)
 
  • Haha
Reactions: Jo
Rob said:
It isn't, as John notes - you need volts as well as amps to get a successful start! But having said that, CCA is not a bad indicator of suitability to the task. A triple starter will take around 170A when cranking with a cold engine. Add in the effects of an aging battery with reduced capacity; poor charging regime; old wiring with increased volt drop and you're quickly running out of road. Not to mention a starter motor that's never been overhauled.
My old Odyssey PC680 sees a minimum terminal voltage of 10.4v when cranking and delivering 170A (which coincidentally happens to be its CCA) - voltage tends to rise once the engine begins to turn. Worth noting that CCA claims by some manufacturers are not reliable and spurious when talking about lithium based cells. I usually recommend a 16Ah lead acid battery as the minimum for a triple.
Click to expand...
I've seen Bosch starters gobble 240 and more amps... with the engine only just turning over.

Clean them up and they suddenly are quite content to spin happily on 160-180 amps.

My 3C has been happy with a 14Ah battery the last 30 years. Sure, doesn't have much in reserve, if the bugger doesn't fire immediately, I've got to start asking myself why. ;)

I usually fit el-cheapo 18 or 20Ah gel batteries, these generally last 4-6 seasons. Once splashed out on a 19Ah Banner, it died after 5 years. This year, I treated the GTL and RGS to 20Ah heavy duty, vibration resistant Landport HVT-1, see how that works out.

piet


piet
 
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