Mikuni

CDHE said:
Need to refocus this thread for just a moment......Mikunis are mounted with plenty of space by removing insulators and shortening spigots by about 5mm. Not quite enough room to install the little conical K&N filters I purchased along with the carbs. It has been suggested that I consider using the stock sheet metal system. Unsure about going about finding rubber boots that would make the connection. Don't have the stock ones to check fit. Any thoughts? Thanks.
Click to expand...
Have you tried Uni Filter or DNA Filters.
 
CDHE said:
Need to refocus this thread for just a moment......Mikunis are mounted with plenty of space by removing insulators and shortening spigots by about 5mm. Not quite enough room to install the little conical K&N filters I purchased along with the carbs. It has been suggested that I consider using the stock sheet metal system. Unsure about going about finding rubber boots that would make the connection. Don't have the stock ones to check fit. Any thoughts? Thanks.
Click to expand...
Have you considered a set of Red's angled inlet stubs? They're very nicely made items CNC machined from billet Aluminium. They drop the carb angle down by 10°. The carbs are happier at a not-so-steep angle, and you get a little more room for pod filters or an airbox.

I don't think Red has a website, but he's here on the forum and also on Facebook (as Redax laverda).
Kieth Nairn also sells them through his Laverda Scozia business in Scotland. Here's a link to his website. Scroll down a bit to see the stubs. http://www.laverdascozia.co.uk/parts/redax.html
I dunno whether Wolfgang in Canada sells them, but it's worth asking as he's closer to your location in USA.
 
Dellortoman said:
Have you considered a set of Red's angled inlet stubs? They're very nicely made items CNC machined from billet Aluminium. They drop the carb angle down by 10°. The carbs are happier at a not-so-steep angle, and you get a little more room for pod filters or an airbox.

I don't think Red has a website, but he's here on the forum and also on Facebook (as Redax laverda).
Kieth Nairn also sells them through his Laverda Scozia business in Scotland. Here's a link to his website. Scroll down a bit to see the stubs. http://www.laverdascozia.co.uk/parts/redax.html
I dunno whether Wolfgang in Canada sells them, but it's worth asking as he's closer to your location in USA.
Click to expand...
Not aware that Red supplies them for the 750s. The angled triple stubs won't fit, unless you want the carbs angled in- or outwards... ;)

750 and triple flanges are at 90° to each other.

piet
 
Thanks Piet. I obviously need to pay closer attention. It's never dawned on me that the inlet stub flanges have a 90° difference in orientation between the twins and triples. Although to be perfectly honest, I didn't look at the picture long enough to notice it's a 750.

Is there any reason angled stubs couldn't be made for the 750 twins? Come to think of it, with the nuts on the sides rather than top/bottom, you could get a more horizontal angle because you don't have to provide clearance for a nut/spanner at the bottom. For a one-off set, welded fabrication would be a simple job.

Perhaps some U-shaped inlet stubs would work, so the carbs sit outboard of the cylinder head with inlet trumpets facing forward for a ram-air effect. Poor man's supercharging. ;)
 
Cam,

The "small-valve" VHB-equipped heads actually have angled stubs. But, obviously, they're too small for the 36mm carbs and stud spacing also differs.

With the introduction of the bigger 36mm carbs, the tank bottom was modified to create space for them.

piet
 
Thanks. Sanded the flanges in figure 8's on my tablesaw's bed. They weren't at all flat. I have the airbox. Can anyone tell me the OD of the Dell's intake? If it is a match, I can hit Wolfgang up for the rubber bits.

And about those gas guzzlers...Anyone checked out the newish Toyota Rav4 Prime.

0-60= 5.7 seconds
MPG= 38
Range on Battery only= 42 miles
AND, it seems they can be adapted for use as a generator.

We just came off a 60 hour long power outage here in Colorado. Were it not for my motorcycle addiction, I think I would be driving one of these in place of my pig of a V8 4runner.
 
CLEMTOG said:
a few years ago I was organsising a day at Bruntingthorpe proving ground, this would have taken the form of several "top speed runs" using two way calculations and a mobile dyno, none of the reprobates that talk about power ,torque and top speed were prepared to put there bikes where there big mouths are and so the day floundered, IIRC, there was a need for 40 or so attendees on the day to break even, I didnt even get 8! and that included me.
CLEM
Click to expand...

Hi Clem, I posted my dyno charts several times here, can send them to you if you want. I have nothing to hide. ;-)

But I agree, that most of the Laverdas that their owners claim to have "top performance" have not proven to be delivering on what the owner claimed. When my brother had a workshop 25 years ago, he offered every owner of a Motorbike to make two dyno runs for a special price, before and after the bike was maintained by him. Many of them agreed to it "allthough the bike runs fine and I expect nothing to be found wrong". How wrong they were... Many of the Triples hardly put out more than 60 HP... Ignition setting wrong, Carbs dirty and miss-adjusted, sometimes even the cams were one tooth off, not to mention about valve clearence etc. etc. etc. Ask Piet, he could write books about how badly maintained many of the Laverdas are...

Michael, an electronic engineer and Laverda-owner since 30+ years who worked professionally on Motorbikes for a while at a well known Laverda-dealer, once rode my Jota. He had a nice red/black smoked Jota himself which he made long distance tours with and was very happy about the performance and was sure that the motor was "one of the strongest" he had ever ridden. I offered him a testride on my Jota. He was gone for more than one hour and I already thought he had issues with the bike, when I heard him coming back. I went outside where he stopped the bike but remained sitting on it, motor off. He looked down to the instruments and did not react when I was talking to him. "Are you OK?" I asked and after some seconds, he looked up to me and said: "What the hell is that, please!?!?"

We discussed a while about what modifications had been done and I heard a while later, that he had taken his motor out and opened it up to see what's wrong. IIRC, he found Yamaha Pistons with way to low compression and some other "gimicks" in the engine from a "tuner" called Claus N. ... The engine must have had barely 60 HP if ever... No wonder, he was totally surprised by my bikes performance, which is not the strongest Laverda in the world, but a nice, rideable and well sorted bike with a bit more performance than standard. Well, almost twice as much HP than what his bike actually put out, so... :sneaky:
 
agree entirely Lothat but YOU were one of those not prepared to come and put it on THE SAME dyno as 40 others, on the same day, and with the same atmospheric conditions, and then have your two way top speed acurately measured, you could have come and proved to us what German engineering is realy like, or not!
Clem
 
And unless bikes are run on the same dyno, you're highly unlikely to get accurate comparison readings anyway. This has already been canvassed on here - no point flogging a dead horse (or is that a worn-out Jota?!)
 
Pretty sure I wasn't even on that event or planed to be there. I also don't see this as a pissing-competition, I measured the results simply to see if the changes I did were resulting in something positive or not. I am not good with the "seat of pants"- feeling. But - You are welcome, Clem, to come to Germany and we'll find a Dyno close by to get our bikes compared if that's what floats your boat. I suggest that who is right pays for the dyno runs... ;)

JFYI: Both bikes were measured before and after changes on 3 different dynos (of the same type though), at different times in the year, different places with different altitudes, temperatures and humidities. The comparable results were all within 1%. If the operators (3 different ones...) do it right, they enter the environmental data into the system and the Dynojet does calculate that in. With that, you get fairly comparable, if not almost equal results. That said, there is still the "rear wheel or engine HP" discussion. As all measurements were taken on acceleration type dynos from Dynojet and I attended all the measurements, I can confirm which value was rear wheel (no measurement of drive train resistance) and which engine HP (with measurement of drive train resistance and according re-calculation of the values). That said, 100 HP or more is also no rocket science, it is simply the result of the concepts of Cico, Sulzbacher etc.: more ccm, higher compression, larger inlet, larger exhaust, larger carbs, "hotter" cams. Simple as that. Cico btw. also put 40mm carbs on the racers... 3 of them per bike, I mean... 😇 less so much german engineering (except for the exhausts) but following italian and austrian engineering (who might have followed german engineering though...?!? Not sure...🤣).

And just to point out: the peak power was just the initial goal. The tests where mostly done not to find out the peak power but to see if the work done improved the power- and - more importantly - the torque curve. In both cases (1000 SFC and Jota), the biggest issue were the exhaust systems...
 
Last edited:
Vacillating between pod filters and working with the original air cleaner set up. Looks like I can use a piece of 55mm ID rubber hose with 90 degree bend to fashion a boot. Can anyone give a gut reaction about whether the bend looks too restrictive?
 

Attachments

  • intake boots.jpeg
    intake boots.jpeg
    186.3 KB · Views: 32
I'll be fitting a pair of Red's Miks to a bike soon and will endeavour to retain the std airbox using std rubber snorkels and fitting the DNA pods inside the airbox - I just like to idea of a remote source for intake air and the slightly enclosed nature of the airbox (with innards removed). Encouraged top her you were able to fit the snorkels using a little heat, Jo.
 
Works well, at least on triples. Reckon it could work just as well on twins, the carb-to-airbox dimensions are similar.

Ideally, the rear of the triple airbox could be trimmed a bit to make a bit more space for the connector tubes.

piet

DSCN8319.JPG
 
I have very out-there porting and inlet tract positioning on my much modified 3c and even with Reds angled manifolds and they too are slightly modified to fit my head I couldn't use the standard airbox even after really wanting to. So it's DNA pods for me.
 
Thinking that I am finally happy with the installation of the TM-36's that I purchased from Tophams. Cut about 1/2" off of the stock inlets as angled ones were not available. I like the stock side covers, so fashioned a fussy blanking plate to replace the stock air cleaner housing and stuffed DNA (OVI-5404) filters in the space I carved out. Reg tabs just fit inside one of the filter pleats!
 

Attachments

  • laverda air cleaners.jpg
    laverda air cleaners.jpg
    175.3 KB · Views: 28
  • laverda plate.jpg
    laverda plate.jpg
    212.5 KB · Views: 27
Good thinking. I opted for remote filters. I used a my sheetmetal version as a mould for a carbon mid-piece (airbox replacement). Flex tubes JUST squeeze through and the BIG DNA filters are under the seat (not shown. Didn't like the look of the SF sidecovers once the airbox was gone.

Carbon mid cover-low kb.JPGCarbon mid cover fitted low kb.JPGFCR Flex intakes side.jpgFCR Flex intakes rear.jpgLeft Carbon Sidecover-fitted.JPG
 
piranha-bro2 said:
Good thinking. I opted for remote filters. I used a my sheetmetal version as a mould for a carbon mid-piece (airbox replacement). Flex tubes JUST squeeze through and the BIG DNA filters are under the seat (not shown. Didn't like the look of the SF sidecovers once the airbox was gone.

View attachment 91633View attachment 91634View attachment 91635View attachment 91636View attachment 91638
Click to expand...
wow. the fcr's require a lot more modification. nice work on the carbon!
 
You must log in or register to reply here.
Back
Top